The broadcasting and sound system covers a wide range, from factories, schools, hotels, stations, terminals, plazas to venues, theaters, stadiums, residential quarters, etc.
In civil construction engineering design, broadcasting systems can be divided into the following categories:
Public broadcasting systems for public areas (squares, stations, terminals, shopping malls, restaurants, corridors, classrooms, etc.) and parking lots. This type of system is mainly used for voice broadcasting, so clarity is paramount. Moreover, such systems often broadcast background music in peacetime, and can be converted to emergency broadcasts in the event of a disaster or emergency.
Broadcast sound system for hotel rooms. Such systems include room audio broadcasts and emergency broadcasts, often delivered by bedside tables located in the guest rooms. The room broadcasts contain a number of freely selectable bands. In the case of emergency broadcasts, room broadcasts are automatically interrupted and automatically switched to emergency broadcasts.
Hall sound reinforcement system represented by auditorium, theater and gymnasium. This is a professional sound reinforcement system, which not only considers electro-acoustic technology problems, but also involves architectural acoustics. Both of them must be balanced and not neglected. Such broadcast systems often have comprehensive multi-purpose requirements, which can be used not only for the sound reinforcement of the venue language, but also for the performances of the arts. For large-scale live sound systems, the electric power is low. Tens of thousands, more than tens of thousands of watts, it is necessary to use high-powered speakers and power amplifiers, in the system configuration and equipment selection have certain requirements, while paying attention to the load of the power line.
Broadcast sound system for conference rooms, lecture halls, etc. Such systems are generally also systems that are set up for background music and emergency broadcasts provided by public broadcasts, but because of their particularity, conference broadcast systems are often set up separately in conference rooms and lecture halls. For higher requirements or international conference halls, special audiovisual systems such as simultaneous interpretation systems, conference voting systems, and large-screen projection televisions are also required.
As can be seen from the above, the broadcast audio systems for various buildings, hotels and other civil buildings can be basically classified into three types:
First, the public address system , this social cable broadcasting system, which includes background music and emergency broadcast functions, usually combined, usually play background music or other programs, and when an emergency such as a fire occurs, it is converted into an alarm broadcast. The microphone used for broadcasting in such a system is generally not in the same room as the speaker broadcasted to the public, so there is no problem of acoustic feedback, and the constant pressure transmission method is a typical system;
Second, the hall sound reinforcement system, this system uses professional audio equipment, and requires a high-powered speaker system and power amplifier, because the microphone and the speaker for sound reinforcement are in the same hall, there is the problem of acoustic feedback and even howling. And because of its short distance, the system generally uses low-impedance direct transmission; Third, the dedicated conference system, although it is also a sound reinforcement system, but has its special requirements, like the sound interpretation system.
The composition of a broadcast sound system <br> Regardless of which broadcast sound system, it can be divided into four parts: program equipment, signal amplification and processing equipment, transmission lines and speaker systems. Program source equipment: The program source is usually provided by radio broadcasting, laser phonograph and recording deck, in addition to microphones and electronic musical instruments.
Signal amplification and processing equipment: including mixers, preamplifiers, power amplifiers and various controllers and audio processing equipment. The primary task of this part of the equipment is signal amplification, followed by signal selection, the mixer and preamplifier have similar roles and status (of course, the mixer has higher function and performance indicators), and their basic function is to complete the signal selection. And pre-amplification, in addition to the volume and sound effects for various adjustments and controls. In order to better perform frequency equalization and timbre beautification, the graphic equalizer is also separately input. This part is the "control center" of the entire broadcast sound system.
The power amplifier amplifies the signal from the preamplifier or the mixer, and then pushes the speaker through the transmission line. Although the transmission line is simple, it has different requirements depending on the system and transmission mode. For the auditorium, theater, etc., because the distance between the power amplifier and the speaker is not far, the direct feeding method of low resistance and large current is generally adopted, and the transmission line is required. Dedicated speaker cable, and for the public broadcasting system , because of the wide service area and long distance, in order to reduce the loss caused by the transmission line, the high-voltage transmission method is often adopted, and the transmission line is not required because of the small transmission current.
Speaker System: The speaker system requires the entire system to be matched, and the choice of its position should be realistic. Auditoriums, theaters, dance halls, sound quality, sound quality requirements, and speakers generally use high-power speakers; and public broadcasting systems , because it is not so high requirements for sound, generally use 3W-6W ceiling speakers is good;
Characteristics of the broadcasting system:
The background music is abbreviated as BCM. It is the abbreviation of BACK GROUD MUSIC. Its main function is to cover up the noise and create a relaxed and harmonious atmosphere. If the listener does not concentrate on listening, he can't distinguish the location of the sound source. The volume is small. A music that creates a relaxed and pleasant atmosphere. Therefore, there are two effects of background music. One is to cover up the environmental noise psychologically, and the other is to create an atmosphere that suits the indoor environment. It is widely used in hotels, hotels, restaurants, shopping malls, hospitals, office buildings and so on. It is not appropriate for a piece of music to be lyrical or to be easily intense.
Background music is not stereo, but mono music. This is because stereo requirements can distinguish the sound source orientation and have a sense of depth, while background music is not conscious to hear where the sound comes from, and does not want The location of the sound source is felt, and the sound source is required to be concealed, and the volume is lighter, so as not to affect the two people's opposite speech.
Characteristics of the fire broadcast function: Fire broadcast is activated when an accident occurs, so it is closely related to personal safety.
Therefore, fire broadcasting has the following characteristics:
The fire alarm signal should have the highest priority in the system, and it can cut off the status of background music and calling people. It should be operated by the fire alarm officer. Transmission cables and speakers should be fire resistant. In the case of AC power outage, the alarm broadcast should also be implemented.
1. General order of public broadcasting engineering design The public broadcasting mentioned here refers to the sound broadcasting of cable transmission, which is usually used in public places, buildings, and communities, for background music broadcasting, paging broadcasting, and forced insertion of forced broadcasting. .
The design of this type of public broadcasting project is usually carried out in the following order:
First of all, we should consider the selection and configuration of broadcast speakers, the selection of broadcast power amplifiers, and broadcast partitions.
2. Selection and configuration of broadcast speakers: Selection of broadcast speakers: In principle, broadcast speakers of different specifications should be selected depending on the environment. For example, in a room with a ceiling ceiling, an embedded, back coverless ceiling speaker should be used. Such as the CH-705 series. This type of speaker has a simple structure, is relatively inexpensive, and is easy to construct. The main disadvantage is that there is no back cover and it is easy to be bitten by insects and rats.
In indoors with only ceilings and no ceilings (such as open-frame shopping malls), ceiling-mounted tubular speakers (ST-708S) or ceiling speakers with rear cover (such as the XT-701N~705 series) should be used. Since the ceiling is equivalent to an infinite baffle, the use of a speaker without a rear cover in the case of a ceiling is not caused by an acoustic short circuit. The situation is very different when there is no ceiling. If you still use a ceilingless speaker without a back cover, the effect will be very poor. In this case, the lifting speaker is used in principle. However, if the investment is too large, a ceiling speaker with a rear cover can also be used. The rear cover with the rear cover ceiling speaker not only has the general mechanical protection effect, but also plays a role in preventing the acoustic short circuit to a certain extent.
In ceiling-free rooms (such as underground parking lots), wall-mounted speakers or indoor sound columns should be used. The former is BG-105, BG-106, BG-108 series, and the latter is SN-302~304 series.
Outdoors, an outdoor sound column or horn should be used. The former is SY-510~540, SY-611~616 series: the latter is like HS-30Q~150Q series. Such sound columns and horns not only have a rainproof function but also a large volume. Since the outdoor environment is empty and there is no reverberation effect, it is necessary to select a variety with a loud volume.
In gardens and grasslands, grass speakers should be used. Such as S-601~S-1001, KT-620, DT-21A~28A series. These speakers are rainproof, sleek, and the volume and sound quality are more elegant.
In the halls with high decoration and high ceilings, it is advisable to use hoisting speakers with elegant shape and harmonious color tone, such as ST-708S series. In the occasions with high arson requirements, arson-type speakers should be used. For example, the ST-708S series. This type of speaker is fully sealed and its outlet is mated to the flame-retardant sleeve.
3. Configuration of the broadcast speaker In principle, the broadcast speaker is arranged in the broadcast service area in a uniform and scattered manner, and the degree of dispersion should ensure that the signal-to-noise ratio in the service area is not less than 15DB. Generally, the noise floor of a high-grade office corridor is about 48~52DB, the noise floor of a super mall is about 58~63DB, and the noise floor of a busy road section is about 70~75DB. Considering the accident, the scene may be very confusing, so for the need of emergency broadcasting, even if the broadcasting service area is an office building, do not estimate the noise floor too low. For this reason, as a general consideration, in addition to the bustling and lively places, it is possible to roughly consider the noise floor as 65~70DB (except in special cases). According to this calculation, the sound pressure level of the broadcast coverage area should be above 80~85DB.
Since broadcast speakers are typically distributed, the sound pressure level of the broadcast coverage area can be approximated as a contribution from a single broadcast speaker. According to the relevant electroacoustic theory, the sound pressure level SPL of the speaker coverage area has the following relationship with the sensitivity level LM of the speaker, the electric power P fed to the speaker, and the distance R between the listening point and the speaker:
SPL=LM+10LgP-20Lgrdb(1)
The sensitivity level of the ceiling speaker is between 88~93DB: the rated power is 3~10W. At 90 DB/8W, the sound pressure level at the speaker BM is about 81 DB. The above does not consider the contribution of the early reflection sound group. Indoors, the contribution of early reflections and adjacent speakers can increase the sound pressure level by about 2~3DB.
According to the above approximate calculation, in the venue where the ceiling is not higher than 3M, the ceiling speakers can be uniformly arranged from each other by 5~8M. If only background music is considered without considering emergency broadcast, the distance can be increased to 8~12M. In addition, the fire accident design and installation specifications applicable to mainland China (hereinafter referred to as “Specifications:â€) have the following rigid rules: “The number of speakers in public places such as walkways, halls, restaurants, etc. should be guaranteed from any part of the floor. Recently, a speaker has a walking distance of no more than 15M. Speakers should be provided at the intersection of the walkway and at the corner. The last speaker at the end of the walkway is no more than 8M from the wall."
There is basically no early reflection sound group in outdoor places, and the effective coverage of a single broadcast speaker can only take the lower limit calculated above. Since the distance corresponding to the lower limit is very short, a sound column composed of a plurality of speakers should be used in principle. The signal power level fed to the speaker group (eg, the sound column) is doubled (provided the group is acceptable), and the sound pressure level can be increased by 3DB. Please pay attention to the meaning of "double". It is doubled from 1 to 2, and it is only twice as important as 2. In addition, for every 1 time increase in distance, the sound pressure level will drop by 6DB. According to the above rules, it is not difficult to estimate the arrangement distance of the outdoor sound column. For example, taking the CS-540 outdoor sound column as an example, its rated power is 40W, which is more than 4 times that of a single ceiling speaker. Therefore, its effective coverage distance is more than twice that of a single ceiling speaker. In fact, this distance can be larger. Because the sensitivity of the column is higher than that of a single ceiling speaker (about 3~6DB), the distance can be doubled for each additional point DB. That is to say, the coverage distance of the 540-sound column can reach 20M or more, but the radiation angle of the sound column is relatively narrow, and it is effective only about 60 to 90 degrees (horizontal angle) in front of it. The specific calculation can be obtained by equation (1).
The choice of broadcast power amplifiers is different from HI-FI power amplifiers. Its main feature is the 70V and 100V constant voltage output terminals. This is because broadcast lines are usually quite long and high-voltage transmission is required to reduce line loss. The most important indicator of a broadcast power amplifier is the rated output power, and the maximum rated output power should be selected, depending on the total power of the broadcast speaker.
For the broadcast system, as long as the total power of the broadcast speaker is less than or equal to the rated power of the power amplifier, and the voltage parameters are the same, it can be arbitrarily matched, but considering the line loss, aging and other factors, the power margin should be left as appropriate. According to the requirements of the "Specifications", the capacity of the power amplifier equipment (equivalent to the rated output power) should generally be calculated as follows:
P=K1.K2.P0∑(2)
P--power amplifier equipment output total electric power (W) P0--each branch (equivalent to partition) simultaneous broadcast maximum electric power P0=KI-PIPI--the first partition speaker rated capacity KI--the first partition requires the coefficient at the same time Service broadcast room program, take 0.2~0.4 background music system, take 0.5~0.6 business broadcast, take 0.7~0.8 fire accident broadcast, take 1.0K1--line attenuation compensation coefficient: 1.26~1.58K2--aging coefficient: 1.2~1.4 According to this, if it is a background music system, the rated output power of the broadcast power amplifier should be about 1.3 times of the total power of the broadcast speaker.
However, all public address systems should, in principle, be able to carry out emergency broadcasts of disasters. Therefore, the system must be equipped with an emergency broadcast amplifier. According to the "Specifications" requirements, the rated output power of the emergency broadcast power amplifier should be 1.5 times the sum of the speaker capacity of the three partitions with the largest capacity of the broadcast speaker. Broadcasting a public broadcasting system is usually divided into several areas, by the management (or Programs) determine which areas must be broadcast, those areas must be suspended, those areas must be inserted into emergency broadcasts, and so on.
The partitioning scheme depends in principle on the needs of the customer. Generally refer to the following rules:
1. Buildings are usually divided into floors. Shopping malls and amusement parks are usually divided by departments. Sports venues are usually divided into stands, residential quarters, resorts usually divided by property management, and so on.
2. The administrative department and the public place should be divided into districts.
3. A separate community where important departments or broadcast speakers have to be arbitrarily adjusted by field personnel. In short, the partition is for ease of management. Any part that needs to be treated separately should be divided into different areas. However, the total power of the broadcast speakers in each zone should not be too large, and it must be compatible with the capacity of the partitioner and the power amplifier. Take the PAS-2013D partitioner in the SYB series as an example. The power capacity of each zone is 500VA, but 10 The total capacity of the districts should not exceed 1000 VA. Accordingly, if 10 zones are operated at full capacity, the average zone should not exceed 100 VA (approximately 100 W).
Community Public Address System Structure The residential community public address system structure consists of four parts:
Broadcast power amplifier, audio input/output, sound equipment, and intelligent playback. The four are organically integrated into a unified public address system . The design of the structure fully takes into account the needs of the community for the function, but also pays attention to the construction cost of the system.
The broadcasting and sound system covers a wide range, from factories, schools, hotels, stations, terminals, plazas to venues, theaters, stadiums, residential quarters, etc.
In civil construction engineering design, broadcasting systems can be divided into the following categories:
Public broadcasting systems for public areas (squares, stations, terminals, shopping malls, restaurants, corridors, classrooms, etc.) and parking lots. This type of system is mainly used for voice broadcasting, so clarity is paramount. Moreover, such systems often broadcast background music in peacetime, and can be converted to emergency broadcasts in the event of a disaster or emergency.
Broadcast sound system for hotel rooms. Such systems include room audio broadcasts and emergency broadcasts, often delivered by bedside tables located in the guest rooms. The room broadcasts contain a number of freely selectable bands. In the case of emergency broadcasts, room broadcasts are automatically interrupted and automatically switched to emergency broadcasts.
Hall sound reinforcement system represented by auditorium, theater and gymnasium. This is a professional sound reinforcement system, which not only considers electro-acoustic technology problems, but also involves architectural acoustics. Both of them must be balanced and not neglected. Such broadcast systems often have comprehensive multi-purpose requirements, which can be used not only for the sound reinforcement of the venue language, but also for the performances of the arts. For large-scale live sound systems, the electric power is low. Tens of thousands, more than tens of thousands of watts, it is necessary to use high-powered speakers and power amplifiers, in the system configuration and equipment selection have certain requirements, while paying attention to the load of the power line.
Broadcast sound system for conference rooms, lecture halls, etc. Such systems are generally also systems that are set up for background music and emergency broadcasts provided by public broadcasts, but because of their particularity, conference broadcast systems are often set up separately in conference rooms and lecture halls. For higher requirements or international conference halls, special audiovisual systems such as simultaneous interpretation systems, conference voting systems, and large-screen projection televisions are also required.
As can be seen from the above, the broadcast audio systems for various buildings, hotels and other civil buildings can be basically classified into three types:
First, the public address system , this social cable broadcasting system, which includes background music and emergency broadcast functions, usually combined, usually play background music or other programs, and when an emergency such as a fire occurs, it is converted into an alarm broadcast. The microphone used for broadcasting in such a system is generally not in the same room as the speaker broadcasted to the public, so there is no problem of acoustic feedback, and the constant pressure transmission method is a typical system;
Second, the hall sound reinforcement system, this system uses professional audio equipment, and requires a high-powered speaker system and power amplifier, because the microphone and the speaker for sound reinforcement are in the same hall, there is the problem of acoustic feedback and even howling. And because of its short distance, the system generally uses low-impedance direct transmission; Third, the dedicated conference system, although it is also a sound reinforcement system, but has its special requirements, like the sound interpretation system.
The composition of a broadcast sound system <br> Regardless of which broadcast sound system, it can be divided into four parts: program equipment, signal amplification and processing equipment, transmission lines and speaker systems. Program source equipment: The program source is usually provided by radio broadcasting, laser phonograph and recording deck, in addition to microphones and electronic musical instruments.
Signal amplification and processing equipment: including mixers, preamplifiers, power amplifiers and various controllers and audio processing equipment. The primary task of this part of the equipment is signal amplification, followed by signal selection, the mixer and preamplifier have similar roles and status (of course, the mixer has higher function and performance indicators), and their basic function is to complete the signal selection. And pre-amplification, in addition to the volume and sound effects for various adjustments and controls. In order to better perform frequency equalization and timbre beautification, the graphic equalizer is also separately input. This part is the "control center" of the entire broadcast sound system.
The power amplifier amplifies the signal from the preamplifier or the mixer, and then pushes the speaker through the transmission line. Although the transmission line is simple, it has different requirements depending on the system and transmission mode. For the auditorium, theater, etc., because the distance between the power amplifier and the speaker is not far, the direct feeding method of low resistance and large current is generally adopted, and the transmission line is required. Dedicated speaker cable, and for the public broadcasting system , because of the wide service area and long distance, in order to reduce the loss caused by the transmission line, the high-voltage transmission method is often adopted, and the transmission line is not required because of the small transmission current.
Speaker System: The speaker system requires the entire system to be matched, and the choice of its position should be realistic. Auditoriums, theaters, dance halls, sound quality, sound quality requirements, and speakers generally use high-power speakers; and public broadcasting systems , because it is not so high requirements for sound, generally use 3W-6W ceiling speakers is good;
Characteristics of the broadcasting system:
The background music is abbreviated as BCM. It is the abbreviation of BACK GROUD MUSIC. Its main function is to cover up the noise and create a relaxed and harmonious atmosphere. If the listener does not concentrate on listening, he can't distinguish the location of the sound source. The volume is small. A music that creates a relaxed and pleasant atmosphere. Therefore, there are two effects of background music. One is to cover up the environmental noise psychologically, and the other is to create an atmosphere that suits the indoor environment. It is widely used in hotels, hotels, restaurants, shopping malls, hospitals, office buildings and so on. It is not appropriate for a piece of music to be lyrical or to be easily intense.
Background music is not stereo, but mono music. This is because stereo requirements can distinguish the sound source orientation and have a sense of depth, while background music is not conscious to hear where the sound comes from, and does not want The location of the sound source is felt, and the sound source is required to be concealed, and the volume is lighter, so as not to affect the two people's opposite speech.
Characteristics of the fire broadcast function: Fire broadcast is activated when an accident occurs, so it is closely related to personal safety.
Therefore, fire broadcasting has the following characteristics:
The fire alarm signal should have the highest priority in the system, and it can cut off the status of background music and calling people. It should be operated by the fire alarm officer. Transmission cables and speakers should be fire resistant. In the case of AC power outage, the alarm broadcast should also be implemented.
1. General order of public broadcasting engineering design The public broadcasting mentioned here refers to the sound broadcasting of cable transmission, which is usually used in public places, buildings, and communities, for background music broadcasting, paging broadcasting, and forced insertion of forced broadcasting. .
The design of this type of public broadcasting project is usually carried out in the following order:
First of all, we should consider the selection and configuration of broadcast speakers, the selection of broadcast power amplifiers, and broadcast partitions.
2. Selection and configuration of broadcast speakers: Selection of broadcast speakers: In principle, broadcast speakers of different specifications should be selected depending on the environment. For example, in a room with a ceiling ceiling, an embedded, back coverless ceiling speaker should be used. Such as the CH-705 series. This type of speaker has a simple structure, is relatively inexpensive, and is easy to construct. The main disadvantage is that there is no back cover and it is easy to be bitten by insects and rats.
In indoors with only ceilings and no ceilings (such as open-frame shopping malls), ceiling-mounted tubular speakers (ST-708S) or ceiling speakers with rear cover (such as the XT-701N~705 series) should be used. Since the ceiling is equivalent to an infinite baffle, the use of a speaker without a rear cover in the case of a ceiling is not caused by an acoustic short circuit. The situation is very different when there is no ceiling. If you still use a ceilingless speaker without a back cover, the effect will be very poor. In this case, the lifting speaker is used in principle. However, if the investment is too large, a ceiling speaker with a rear cover can also be used. The rear cover with the rear cover ceiling speaker not only has the general mechanical protection effect, but also plays a role in preventing the acoustic short circuit to a certain extent.
In ceiling-free rooms (such as underground parking lots), wall-mounted speakers or indoor sound columns should be used. The former is BG-105, BG-106, BG-108 series, and the latter is SN-302~304 series.
Outdoors, an outdoor sound column or horn should be used. The former is SY-510~540, SY-611~616 series: the latter is like HS-30Q~150Q series. Such sound columns and horns not only have a rainproof function but also a large volume. Since the outdoor environment is empty and there is no reverberation effect, it is necessary to select a variety with a loud volume.
In gardens and grasslands, grass speakers should be used. Such as S-601~S-1001, KT-620, DT-21A~28A series. These speakers are rainproof, sleek, and the volume and sound quality are more elegant.
In the halls with high decoration and high ceilings, it is advisable to use hoisting speakers with elegant shape and harmonious color tone, such as ST-708S series. In the occasions with high arson requirements, arson-type speakers should be used. For example, the ST-708S series. This type of speaker is fully sealed and its outlet is mated to the flame-retardant sleeve.
3. Configuration of the broadcast speaker In principle, the broadcast speaker is arranged in the broadcast service area in a uniform and scattered manner, and the degree of dispersion should ensure that the signal-to-noise ratio in the service area is not less than 15DB. Generally, the noise floor of a high-grade office corridor is about 48~52DB, the noise floor of a super mall is about 58~63DB, and the noise floor of a busy road section is about 70~75DB. Considering the accident, the scene may be very confusing, so for the need of emergency broadcasting, even if the broadcasting service area is an office building, do not estimate the noise floor too low. For this reason, as a general consideration, in addition to the bustling and lively places, it is possible to roughly consider the noise floor as 65~70DB (except in special cases). According to this calculation, the sound pressure level of the broadcast coverage area should be above 80~85DB.
Since broadcast speakers are typically distributed, the sound pressure level of the broadcast coverage area can be approximated as a contribution from a single broadcast speaker. According to the relevant electroacoustic theory, the sound pressure level SPL of the speaker coverage area has the following relationship with the sensitivity level LM of the speaker, the electric power P fed to the speaker, and the distance R between the listening point and the speaker:
SPL=LM+10LgP-20Lgrdb(1)
The sensitivity level of the ceiling speaker is between 88~93DB: the rated power is 3~10W. At 90 DB/8W, the sound pressure level at the speaker BM is about 81 DB. The above does not consider the contribution of the early reflection sound group. Indoors, the contribution of early reflections and adjacent speakers can increase the sound pressure level by about 2~3DB.
According to the above approximate calculation, in the venue where the ceiling is not higher than 3M, the ceiling speakers can be uniformly arranged from each other by 5~8M. If only background music is considered without considering emergency broadcast, the distance can be increased to 8~12M. In addition, the fire accident design and installation specifications applicable to mainland China (hereinafter referred to as “Specifications:â€) have the following rigid rules: “The number of speakers in public places such as walkways, halls, restaurants, etc. should be guaranteed from any part of the floor. Recently, a speaker has a walking distance of no more than 15M. Speakers should be provided at the intersection of the walkway and at the corner. The last speaker at the end of the walkway is no more than 8M from the wall."
There is basically no early reflection sound group in outdoor places, and the effective coverage of a single broadcast speaker can only take the lower limit calculated above. Since the distance corresponding to the lower limit is very short, a sound column composed of a plurality of speakers should be used in principle. The signal power level fed to the speaker group (eg, the sound column) is doubled (provided the group is acceptable), and the sound pressure level can be increased by 3DB. Please pay attention to the meaning of "double". It is doubled from 1 to 2, and it is only twice as important as 2. In addition, for every 1 time increase in distance, the sound pressure level will drop by 6DB. According to the above rules, it is not difficult to estimate the arrangement distance of the outdoor sound column. For example, taking the CS-540 outdoor sound column as an example, its rated power is 40W, which is more than 4 times that of a single ceiling speaker. Therefore, its effective coverage distance is more than twice that of a single ceiling speaker. In fact, this distance can be larger. Because the sensitivity of the column is higher than that of a single ceiling speaker (about 3~6DB), the distance can be doubled for each additional point DB. That is to say, the coverage distance of the 540-sound column can reach 20M or more, but the radiation angle of the sound column is relatively narrow, and it is effective only about 60 to 90 degrees (horizontal angle) in front of it. The specific calculation can be obtained by equation (1).
The choice of broadcast power amplifiers is different from HI-FI power amplifiers. Its main feature is the 70V and 100V constant voltage output terminals. This is because broadcast lines are usually quite long and high-voltage transmission is required to reduce line loss. The most important indicator of a broadcast power amplifier is the rated output power, and the maximum rated output power should be selected, depending on the total power of the broadcast speaker.
For the broadcast system, as long as the total power of the broadcast speaker is less than or equal to the rated power of the power amplifier, and the voltage parameters are the same, it can be arbitrarily matched, but considering the line loss, aging and other factors, the power margin should be left as appropriate. According to the requirements of the "Specifications", the capacity of the power amplifier equipment (equivalent to the rated output power) should generally be calculated as follows:
P=K1.K2.P0∑(2)
P--power amplifier equipment output total electric power (W) P0--each branch (equivalent to partition) simultaneous broadcast maximum electric power P0=KI-PIPI--the first partition speaker rated capacity KI--the first partition requires the coefficient at the same time Service broadcast room program, take 0.2~0.4 background music system, take 0.5~0.6 business broadcast, take 0.7~0.8 fire accident broadcast, take 1.0K1--line attenuation compensation coefficient: 1.26~1.58K2--aging coefficient: 1.2~1.4 According to this, if it is a background music system, the rated output power of the broadcast power amplifier should be about 1.3 times of the total power of the broadcast speaker.
However, all public address systems should, in principle, be able to carry out emergency broadcasts of disasters. Therefore, the system must be equipped with an emergency broadcast amplifier. According to the "Specifications" requirements, the rated output power of the emergency broadcast power amplifier should be 1.5 times the sum of the speaker capacity of the three partitions with the largest capacity of the broadcast speaker. Broadcasting a public broadcasting system is usually divided into several areas, by the management (or Programs) determine which areas must be broadcast, those areas must be suspended, those areas must be inserted into emergency broadcasts, and so on.
The partitioning scheme depends in principle on the needs of the customer. Generally refer to the following rules:
1. Buildings are usually divided into floors. Shopping malls and amusement parks are usually divided by departments. Sports venues are usually divided into stands, residential quarters, resorts usually divided by property management, and so on.
2. The administrative department and the public place should be divided into districts.
3. A separate community where important departments or broadcast speakers have to be arbitrarily adjusted by field personnel. In short, the partition is for ease of management. Any part that needs to be treated separately should be divided into different areas. However, the total power of the broadcast speakers in each zone should not be too large, and it must be compatible with the capacity of the partitioner and the power amplifier. Take the PAS-2013D partitioner in the SYB series as an example. The power capacity of each zone is 500VA, but 10 The total capacity of the districts should not exceed 1000 VA. Accordingly, if 10 zones are operated at full capacity, the average zone should not exceed 100 VA (approximately 100 W).
Community Public Address System Structure The residential community public address system structure consists of four parts:
Broadcast power amplifier, audio input/output, sound equipment, and intelligent playback. The four are organically integrated into a unified public address system . The design of the structure fully takes into account the needs of the community for the function, but also pays attention to the construction cost of the system.
The broadcasting and sound system covers a wide range, from factories, schools, hotels, stations, terminals, plazas to venues, theaters, stadiums, residential quarters, etc.
In civil construction engineering design, broadcasting systems can be divided into the following categories:
Public broadcasting systems for public areas (squares, stations, terminals, shopping malls, restaurants, corridors, classrooms, etc.) and parking lots. This type of system is mainly used for voice broadcasting, so clarity is paramount. Moreover, such systems often broadcast background music in peacetime, and can be converted to emergency broadcasts in the event of a disaster or emergency.
Broadcast sound system for hotel rooms. Such systems include room audio broadcasts and emergency broadcasts, often delivered by bedside tables located in the guest rooms. The room broadcasts contain a number of freely selectable bands. In the case of emergency broadcasts, room broadcasts are automatically interrupted and automatically switched to emergency broadcasts.
Hall sound reinforcement system represented by auditorium, theater and gymnasium. This is a professional sound reinforcement system, which not only considers electro-acoustic technology problems, but also involves architectural acoustics. Both of them must be balanced and not neglected. Such broadcast systems often have comprehensive multi-purpose requirements, which can be used not only for the sound reinforcement of the venue language, but also for the performances of the arts. For large-scale live sound systems, the electric power is low. Tens of thousands, more than tens of thousands of watts, it is necessary to use high-powered speakers and power amplifiers, in the system configuration and equipment selection have certain requirements, while paying attention to the load of the power line.
Broadcast sound system for conference rooms, lecture halls, etc. Such systems are generally also systems that are set up for background music and emergency broadcasts provided by public broadcasts, but because of their particularity, conference broadcast systems are often set up separately in conference rooms and lecture halls. For higher requirements or international conference halls, special audiovisual systems such as simultaneous interpretation systems, conference voting systems, and large-screen projection televisions are also required.
As can be seen from the above, the broadcast audio systems for various buildings, hotels and other civil buildings can be basically classified into three types:
First, the public address system , this social cable broadcasting system, which includes background music and emergency broadcast functions, usually combined, usually play background music or other programs, and when an emergency such as a fire occurs, it is converted into an alarm broadcast. The microphone used for broadcasting in such a system is generally not in the same room as the speaker broadcasted to the public, so there is no problem of acoustic feedback, and the constant pressure transmission method is a typical system;
Second, the hall sound reinforcement system, this system uses professional audio equipment, and requires a high-powered speaker system and power amplifier, because the microphone and the speaker for sound reinforcement are in the same hall, there is the problem of acoustic feedback and even howling. And because of its short distance, the system generally uses low-impedance direct transmission; Third, the dedicated conference system, although it is also a sound reinforcement system, but has its special requirements, like the sound interpretation system.
广æ’音å“ç³»ç»Ÿçš„ç»„æˆ <br> ä¸ç®¡å“ªä¸€ç§å¹¿æ’音å“系统，它基本å¯åˆ†å››ä¸ªéƒ¨åˆ†ï¼šèŠ‚目设备ã€ä¿¡å·çš„放大和处ç†è®¾å¤‡ã€ä¼ 输线路和扬声器系统。节目æºè®¾å¤‡ï¼šèŠ‚ç›®æºé€šå¸¸ä¸ºæ— 线电广æ’，激光唱机和录音å¡åº§ç‰è®¾å¤‡æ供，æ¤å¤–è¿˜æœ‰ä¼ å£°å™¨ã€ç”µåä¹å™¨ç‰ã€‚
ä¿¡å·æ”¾å¤§å’Œå¤„ç†è®¾å¤‡ï¼šåŒ…括调音å°ã€å‰ç½®æ”¾å¤§å™¨ã€åŠŸçŽ‡æ”¾å¤§å™¨å’Œå„ç§æŽ§åˆ¶å™¨åŠéŸ³å“åŠ å·¥è®¾å¤‡ç‰ã€‚这部分设备的首è¦ä»»åŠ¡æ˜¯ä¿¡å·æ”¾å¤§ï¼Œå…¶æ¬¡æ˜¯ä¿¡å·çš„选择，调音å°å’Œå‰ç½®æ”¾å¤§å™¨ä½œç”¨å’Œåœ°ä½ç›¸ä¼¼ï¼ˆå½“然调音å°çš„åŠŸèƒ½å’Œæ€§èƒ½æŒ‡æ ‡æ›´é«˜ï¼‰ï¼Œå®ƒä»¬çš„åŸºæœ¬åŠŸèƒ½æ˜¯å®Œæˆä¿¡å·çš„选择和å‰ç½®æ”¾å¤§ï¼Œæ¤å¤–还担负音é‡å’ŒéŸ³å“效果进行å„ç§è°ƒæ•´å’ŒæŽ§åˆ¶ã€‚有时为了更好地进行频率å‡è¡¡å’ŒéŸ³è‰²ç¾ŽåŒ–，还å¦å¤–å•ç‹¬æŠ•å…¥å›¾ç¤ºå‡è¡¡å™¨ã€‚这部分是整个广æ’音å“系统的“控制ä¸å¿ƒâ€ã€‚
功率放大器则将å‰ç½®æ”¾å¤§å™¨æˆ–调音å°é€æ¥çš„ä¿¡å·è¿›è¡ŒåŠŸçŽ‡æ”¾å¤§ï¼Œå†é€šè¿‡ä¼ è¾“çº¿åŽ»æŽ¨åŠ¨æ‰¬å£°å™¨æ”¾å£°ã€‚ä¼ è¾“çº¿è·¯è™½ç„¶ç®€å•ï¼Œä½†éšç€ç³»ç»Ÿå’Œä¼ 输方å¼çš„ä¸åŒè€Œæœ‰ä¸åŒçš„è¦æ±‚ï¼Œå¯¹ç¤¼å ‚ã€å‰§åœºç‰ï¼Œç”±äºŽåŠŸçŽ‡æ”¾å¤§å™¨ä¸Žæ‰¬å£°å™¨çš„è·ç¦»ä¸è¿œï¼Œä¸€èˆ¬é‡‡ç”¨ä½Žé˜»å¤§ç”µæµçš„直接馈é€æ–¹å¼ï¼Œä¼ 输线è¦æ±‚用专用喇å线，而对公共广æ’系统 ，由于æœåŠ¡åŒºåŸŸå¹¿ï¼Œè·ç¦»é•¿ï¼Œä¸ºäº†å‡å°‘ä¼ è¾“çº¿è·¯å¼•èµ·çš„æŸè€—ï¼Œå¾€å¾€é‡‡ç”¨é«˜åŽ‹ä¼ è¾“æ–¹å¼ï¼Œç”±äºŽä¼ 输电æµå°ï¼Œæ•…å¯¹ä¼ è¾“çº¿è¦æ±‚ä¸é«˜ã€‚
扬声器系统：扬声器系统è¦æ±‚整个系统è¦åŒ¹é…，åŒæ—¶å…¶ä½ç½®çš„选择也è¦åˆ‡åˆå®žé™…ã€‚ç¤¼å ‚ã€å‰§åœºã€æŒèˆžåŽ…音色ã€éŸ³è´¨è¦æ±‚高，而扬声器一般用大功率音箱；而公共广æ’系统 ，由于它对音色è¦æ±‚ä¸æ˜¯é‚£ä¹ˆé«˜ï¼Œä¸€èˆ¬ç”¨3W-6W天花喇åå³å¥½ï¼›
广æ’系统的特点：
背景音ä¹ç®€ç§°BCM，是BACK GROUD MUSIC的缩写，它的主è¦ä½œç”¨æ˜¯æŽ©ç›–å™ªå£°å¹¶åˆ›é€ ä¸€ä¸è½»æ¾å’Œè°çš„气氛，å¬çš„人若ä¸ä¸“心å¬ï¼Œå°±ä¸èƒ½è¾¨åˆ«å…¶å£°æºä½ç½®ï¼ŒéŸ³é‡è¾ƒå°ï¼Œæ˜¯ä¸€ç§èƒ½åˆ›é€ è½»æ¾æ„‰å¿«çŽ¯å¢ƒæ°”氛的音ä¹ã€‚å› æ¤ï¼ŒèƒŒæ™¯éŸ³ä¹çš„效果有两个，一是心ç†ä¸ŠæŽ©ç›–çŽ¯å¢ƒå™ªå£°ï¼ŒäºŒæ˜¯åˆ›é€ ä¸Žå®¤å†…çŽ¯å¢ƒç›¸é€‚åº”çš„æ°”æ°›ï¼Œå®ƒåœ¨å®¾é¦†ã€é…’店ã€é¤åŽ…ã€å•†åœºã€åŒ»é™¢ã€åŠžå…¬æ¥¼ç‰å¹¿æ³›çš„应用。ä¹æ›²åº”æ˜¯æŠ’æƒ…é£Žæ ¼çš„æˆ–æ˜¯è½»æ¾çš„强烈激性的ä¹æ›²æ˜¯ä¸é€‚宜。
背景音ä¹ä¸æ˜¯ç«‹ä½“声，而是å•å£°é“音ä¹ï¼Œè¿™æ˜¯å› 为立体声è¦æ±‚能分辨出声æºæ–¹ä½ï¼Œå¹¶ä¸”有纵深感，而背景音ä¹åˆ™æ˜¯ä¸ä¸“心å¬å°±æ„识ä¸åˆ°å£°éŸ³ä»Žä½•å¤„æ¥ï¼Œå¹¶ä¸å¸Œæœ›ä¸ºäººæ„Ÿè§‰å‡ºå£°æºçš„ä½ç½®ï¼Œä»¥è‡³è¦æ±‚把声æºéšè”½èµ·æ¥ï¼Œè€ŒéŸ³é‡è¦è¾ƒè½»ï¼Œä»¥ä¸å½±å“两人对é¢è®²è¯ä¸ºåŽŸåˆ™ã€‚
消防广æ’功能的特点：消防广æ’是在有事故å‘生时å¯ç”¨ï¼Œæ‰€ä»¥å®ƒè·Ÿäººèº«çš„安全有密切关系.
å› è€Œæ¶ˆé˜²å¹¿æ’有以下特点：
消防报è¦ä¿¡å·åº”在系统ä¸å…·æœ‰æœ€é«˜ä¼˜å…ˆæƒï¼Œå¯å¯¹èƒŒæ™¯éŸ³ä¹å’Œå‘¼å«æ‰¾äººç‰çŠ¶æ€å…·æœ‰åˆ‡æ–功能。应使于消防报è¦å€¼ç人员æ“ä½œã€‚ä¼ è¾“ç”µç¼†å’Œæ‰¬å£°å™¨åº”å…·æœ‰é˜²ç«ç‰¹æ€§ã€‚在交æµç”µæ–电的情况下也è¦ä¿è¯æŠ¥è¦å¹¿æ’实施。
1ã€å…¬å…±å¹¿æ’工程设计的一般顺åºè¿™é‡Œæ‰€è¯´çš„公共广æ’æ˜¯æŒ‡æœ‰çº¿ä¼ è¾“çš„å£°éŸ³å¹¿æ’，通常用于公共场所ã€å¤§åŽ¦ã€å°åŒºå†…部，供背景音ä¹å¹¿æ’ã€å¯»å‘¼å¹¿æ’以åŠå¼ºè¡Œæ’入的ç¾å®³æ€§å¹¿æ’使用。
这一类公共广æ’工程的设计，通常按下列顺åºè¿›è¡Œï¼š
首先应考虑广æ’扬声器的选用ã€é…置，广æ’功放的选用，广æ’分区。
2ã€å¹¿æ’扬声器的选用和é…置广æ’扬声器的选用：原则上应视环境选用ä¸åŒå“ç§è§„æ ¼çš„å¹¿æ’扬声器。 For example, in a room with a ceiling ceiling, an embedded, back coverless ceiling speaker should be used.如CH-705系列。 This type of speaker has a simple structure, is relatively inexpensive, and is easy to construct. The main disadvantage is that there is no back cover and it is easy to be bitten by insects and rats.
在仅有框架åŠé¡¶è€Œæ— 天花æ¿çš„室内（如开架å¼å•†åœºï¼‰ï¼Œå®œç”¨åŠè£…å¼ç’型音箱（ST-708S）或有åŽç½©çš„天花扬声器（如XT-701N~705系列）。由于天花æ¿ç›¸å½“于一å—æ— é™å¤§çš„éšœæ¿ï¼Œæ‰€ä»¥è‡ªçˆ±æœ‰å¤©èŠ±æ¿çš„æ¡ä»¶ä¸‹ä½¿ç”¨æ— åŽç½©çš„扬声器也ä¸ä¼šå¼•èµ·å£°çŸè·¯ã€‚而没有天花æ¿æ—¶æƒ…况就大ä¸ç›¸åŒï¼Œå¦‚æžœä»ç”¨æ— åŽç½©çš„天花扬声器，效果会很差。这时原则上使用åŠè£…音箱。 However, if the investment is too large, a ceiling speaker with a rear cover can also be used.有åŽç½©å¤©èŠ±æ‰¬å£°å™¨çš„åŽç½©ä¸ä»…有一般的机械防护作用，而且在一定程度上起到防æ¢å£°çŸè·¯çš„作用。
åœ¨æ— åŠé¡¶çš„室内（例如地下åœè½¦åœºï¼‰ï¼Œåˆ™å®œé€‰ç”¨å£æŒ‚å¼æ‰¬å£°å™¨æˆ–室内音柱。å‰è€…如BG-105ã€BG-106ã€BG-108系列，åŽè€…如SN-302~304系列。
在室外，宜选用室外音柱或å·è§’。å‰è€…如SY-510~540ã€SY-611~616系列：åŽè€…如HS-30Q~150Q系列。这类音柱和å·è§’ä¸ä»…有防雨功能而且音é‡è¾ƒå¤§ï¼Œç”±äºŽå®¤å¤–环境空旷，没有混å“效应，选择音é‡è¾ƒå¤§çš„å“ç§æ˜¯å¿…须的。
In gardens and grasslands, grass speakers should be used.如S-601~S-1001ã€KT-620ã€DT-21A~28Aç‰ç³»åˆ—。 These speakers are rainproof, sleek, and the volume and sound quality are more elegant.
在装修讲究ã€é¡¶æ£šé«˜é˜”çš„åŽ…å ‚ï¼Œå®œé€‰ç”¨é€ åž‹ä¼˜é›…ã€è‰²è°ƒå’Œè°çš„åŠè£…å¼æ‰¬å£°å™¨ï¼Œå¦‚ST-708S系列，在放ç«è¦æ±‚较高的场åˆï¼Œå®œé€‰ç”¨æ”¾ç«åž‹çš„扬声器。例如ST-708S系列。 This type of speaker is fully sealed and its outlet is mated to the flame-retardant sleeve.
3ã€å¹¿æ’扬声器的é…置广æ’扬声器原则上以å‡åŒ€ã€åˆ†æ•£çš„原则é…置于广æ’æœåŠ¡åŒºï¼Œå…¶åˆ†æ•£çš„程度应ä¿è¯æœåŠ¡åŒºå†…的信噪比ä¸å°äºŽ15DB。 通常，高级写å—楼走廊的本底噪声约为48~52DB，超级商场的本底噪声约58~63DB，ç¹åŽè·¯æ®µçš„本底噪声约为70~75DB。考虑到å‘生事故时，现场å¯èƒ½ååˆ†æ··ä¹±ï¼Œå› æ¤ä¸ºäº†ç´§æ€¥å¹¿æ’的需è¦ï¼Œå³ä½¿å¹¿æ’æœåŠ¡åŒºæ˜¯å†™å—楼，也ä¸è¦æŠŠæœ¬åº•å™ªå£°ä¼°è®¡å¾—太低。æ¤æ¤ï¼Œä½œä¸ºä¸€èˆ¬è€ƒè™‘，除了ç¹åŽçƒé—¹çš„场所，ä¸å¦¨å¤§è‡´æŠŠæœ¬åº•å™ªå£°è§†ä¸º65~70DB（特殊情况除外）。照æ¤æŽ¨ç®—，广æ’覆盖区的声压级宜在80~85DB以上。
鉴于广æ’扬声器通常是分散é…置的，所以广æ’覆盖区的声压级å¯ä»¥è¿‘似地认为是å•ä¸ªå¹¿æ’æ‰¬å£°å™¨çš„è´¡çŒ®ã€‚æ ¹æ®æœ‰å…³çš„电声å¦ç†è®ºï¼Œæ‰¬å£°å™¨è¦†ç›–区的声压级SPLåŒæ‰¬å£°å™¨çš„çµæ•åº¦çº§LMã€é¦ˆç»™æ‰¬å£°å™¨çš„电功率Pã€å¬éŸ³ç‚¹ä¸Žæ‰¬å£°å™¨çš„è·ç¦»Rç‰æœ‰å¦‚下关系：
SPL=LM+10LgP-20Lgrdb（1）
天花扬声器的çµæ•åº¦çº§åœ¨88~93DB之间：é¢å®šåŠŸçŽ‡ä¸º3~10W。以90DB/8W算，在离扬声器BM处的声压级约为81DB。以上算未考虑早期å射声群的贡献。在室内，早期å射声群和邻近扬声器的贡献å¯ä½¿å£°åŽ‹çº§å¢žåŠ 2~3DBå·¦å³ã€‚
æ ¹æ®ä»¥ä¸Šè¿‘似计算，在天花æ¿ä¸é«˜äºŽ3M的场馆内，天花扬声器大体å¯ä»¥äº’相è·ç¦»5~8Må‡åŒ€é…置。如果仅考虑背景音ä¹è€Œä¸è€ƒè™‘紧急广æ’，则该è·ç¦»å¯ä»¥å¢žå¤§è‡³8~12M。å¦å¤–，适用于ä¸å›½å¤§é™†çš„ç«ç¾äº‹æ•…广æ’设计安装规范（以下简称“规范：）有以下一些硬性规定：“走é“ã€å¤§åŽ…ã€é¤åŽ…ç‰å…¬ä¼—场所，扬声器的é…置数é‡ï¼Œåº”能ä¿è¯ä»Žæœ¬å±‚任何部ä½åˆ°æœ€è¿‘一个扬声器的æ¥è¡Œè·ç¦»ä¸è¶…过15M。 Speakers should be provided at the intersection of the walkway and at the corner.èµ°é“末端最åŽä¸€ä¸ªæ‰¬å£°å™¨è·å¢™ä¸å¤§äºŽ8Mâ€ã€‚
There is basically no early reflection sound group in outdoor places, and the effective coverage of a single broadcast speaker can only take the lower limit calculated above. Since the distance corresponding to the lower limit is very short, a sound column composed of a plurality of speakers should be used in principle.馈给扬声器群组（例如音柱）的信å·ç”µåŠŸçŽ‡æ¯å¢žåŠ 一å€ï¼ˆå‰æ是该群组能够接å—），声压级å¯æå‡3DB。请注æ„“一å€â€çš„å«ä¹‰ã€‚ç”±1增至2是一å€ï¼Œè€Œç”±2增至关é‡è¦æ‰æ˜¯ä¸€å€ã€‚å¦å¤–，è·ç¦»æ¯å¢žåŠ 1å€ï¼Œå£°åŽ‹çº§å°†ä¸‹é™6DBã€‚æ ¹æ®ä¸Šè¿°è§„则ä¸éš¾æŽ¨ç®—室外音柱的é…ç½®è·ç¦»ã€‚例如，以CS-540室外音柱为例，其é¢å®šåŠŸçŽ‡ä¸º40W，是å•ä¸ªå¤©èŠ±æ‰¬å£°å™¨çš„4å€ä»¥ä¸Šã€‚ Therefore, its effective coverage distance is more than twice that of a single ceiling speaker.事实上，这个è·ç¦»è¿˜å¯ä»¥å¤§ä¸€äº›ã€‚å› ä¸ºéŸ³æŸ±çš„çµæ•åº¦æ¯”å•ä¸ªå¤©èŠ±æ‰¬å£°å™¨è¦é«˜ï¼ˆçº¦é«˜3~6DB），而æ¯å¢žåŠ 点DB，è·ç¦»å°±å¯å†åŠ å€ã€‚也就是说540音柱的覆盖è·ç¦»å¯ä»¥è¾¾20M以上，但音柱的è¾å°„角比较窄，仅在其æ£å‰æ–¹çº¦60~90度（水平角）左å³æœ‰æ•ˆã€‚具体计算å¯ç”¨å¼ï¼ˆ1）。
广æ’功放的选用广æ’功放ä¸åŒäºŽHI-FI功放，其最主è¦çš„特å¾æ˜¯å…·æœ‰70Vå’Œ100Væ’压输出端å，这是由于广æ’çº¿è·¯é€šå¸¸éƒ½ç›¸å½“é•¿ï¼Œé¡»ç”¨é«˜åŽ‹ä¼ è¾“æ‰èƒ½å‡å°‘线路æŸè€—。广æ’功放的最é‡è¦æŒ‡æ ‡æ˜¯é¢å®šè¾“出功率，应选用多大的é¢å®šè¾“出功率，须视广æ’扬声器的总功率而定。
对于广æ’系统æ¥è¯´ï¼Œåªè¦å¹¿æ’扬声器的总功率å°äºŽæˆ–ç‰äºŽåŠŸæ”¾çš„é¢å®šåŠŸçŽ‡ï¼Œè€Œä¸”电压å‚数相åŒï¼Œå³å¯éšæ„é…接，但考虑到线路æŸè€—ã€è€åŒ–ç‰å› ç´ ï¼Œåº”é€‚å½“ç•™æœ‰åŠŸçŽ‡ä½™é‡ã€‚按照“规范â€çš„è¦æ±‚，功放设备的容é‡ï¼ˆç›¸å½“于é¢å®šè¾“出功率）一般应按下å¼è®¡ç®—：
P=K1.K2.P0∑(2)
P--功放设备输出总电功率（W） P0--æ¯ä¸€åˆ†è·¯ï¼ˆç›¸å½“于分区）åŒæ—¶å¹¿æ’时最大电功率P0=KI-PIPI--第I分区扬声器é¢å®šå®¹é‡KI--第I分区åŒæ—¶éœ€è¦ç³»æ•°æœåŠ¡æ€§å¹¿æ’客房节目，å–0.2~0.4背景音ä¹ç³»ç»Ÿï¼Œå–0.5~0.6业务性广æ’，å–0.7~0.8ç«ç¾äº‹æ•…广æ’，å–1.0K1--线路衰耗补å¿ç³»æ•°ï¼š1.26~1.58K2--è€åŒ–系数：1.2~1.4æ®æ¤ï¼Œå¦‚果是背景音ä¹ç³»ç»Ÿï¼Œå¹¿æ’功放的é¢å®šè¾“出功率应是广æ’扬声器总功率的1.3å€å·¦å³ã€‚
但是，所有公共广æ’系统原则上应能进行ç¾å®³äº‹æ•…紧急广æ’ã€‚å› æ¤ï¼Œç³»ç»Ÿé¡»è®¾ç½®ç´§æ€¥å¹¿æ’åŠŸæ”¾ã€‚æ ¹æ®â€œè§„范â€è¦æ±‚，紧急广æ’功放的é¢å®šè¾“出功率应是广æ’扬声器容é‡æœ€å¤§çš„三个分区ä¸ä¸æ‰¬å£°å™¨å®¹é‡æ€»å’Œçš„1.5å€å¹¿æ’分区一个公共广æ’系统通常划分æˆè‹¥å¹²ä¸ªåŒºåŸŸï¼Œç”±ç®¡ç†äººå‘˜ï¼ˆæˆ–预编程åºï¼‰å†³å®šé‚£äº›åŒºåŸŸé¡»å‘布广æ’ã€é‚£äº›åŒºåŸŸé¡»æš‚åœå¹¿æ’ã€é‚£äº›åŒºåŸŸé¡»æ’入紧急广æ’ç‰ç‰ã€‚
分区方案原则上å–决客户的需è¦ã€‚通常å¯å‚考下列规则：
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In civil construction engineering design, broadcasting systems can be divided into the following categories:
Public broadcasting systems for public areas (squares, stations, terminals, shopping malls, restaurants, corridors, classrooms, etc.) and parking lots. This type of system is mainly used for voice broadcasting, so clarity is paramount. Moreover, such systems often broadcast background music in peacetime, and can be converted to emergency broadcasts in the event of a disaster or emergency.
Broadcast sound system for hotel rooms. Such systems include room audio broadcasts and emergency broadcasts, often delivered by bedside tables located in the guest rooms. The room broadcasts contain a number of freely selectable bands. In the case of emergency broadcasts, room broadcasts are automatically interrupted and automatically switched to emergency broadcasts.
Hall sound reinforcement system represented by auditorium, theater and gymnasium. This is a professional sound reinforcement system, which not only considers electro-acoustic technology problems, but also involves architectural acoustics. Both of them must be balanced and not neglected. Such broadcast systems often have comprehensive multi-purpose requirements, which can be used not only for the sound reinforcement of the venue language, but also for the performances of the arts. For large-scale live sound systems, the electric power is low. Tens of thousands, more than tens of thousands of watts, it is necessary to use high-powered speakers and power amplifiers, in the system configuration and equipment selection have certain requirements, while paying attention to the load of the power line.
Broadcast sound system for conference rooms, lecture halls, etc. Such systems are generally also systems that are set up for background music and emergency broadcasts provided by public broadcasts, but because of their particularity, conference broadcast systems are often set up separately in conference rooms and lecture halls. For higher requirements or international conference halls, special audiovisual systems such as simultaneous interpretation systems, conference voting systems, and large-screen projection televisions are also required.
As can be seen from the above, the broadcast audio systems for various buildings, hotels and other civil buildings can be basically classified into three types:
First, the public address system , this social cable broadcasting system, which includes background music and emergency broadcast functions, usually combined, usually play background music or other programs, and when an emergency such as a fire occurs, it is converted into an alarm broadcast. The microphone used for broadcasting in such a system is generally not in the same room as the speaker broadcasted to the public, so there is no problem of acoustic feedback, and the constant pressure transmission method is a typical system;
Second, the hall sound reinforcement system, this system uses professional audio equipment, and requires a high-powered speaker system and power amplifier, because the microphone and the speaker for sound reinforcement are in the same hall, there is the problem of acoustic feedback and even howling. And because of its short distance, the system generally uses low-impedance direct transmission; Third, the dedicated conference system, although it is also a sound reinforcement system, but has its special requirements, like the sound interpretation system.
The composition of a broadcast sound system <br> Regardless of which broadcast sound system, it can be divided into four parts: program equipment, signal amplification and processing equipment, transmission lines and speaker systems. Program source equipment: The program source is usually provided by radio broadcasting, laser phonograph and recording deck, in addition to microphones and electronic musical instruments.
Signal amplification and processing equipment: including mixers, preamplifiers, power amplifiers and various controllers and audio processing equipment. The primary task of this part of the equipment is signal amplification, followed by signal selection, the mixer and preamplifier have similar roles and status (of course, the mixer has higher function and performance indicators), and their basic function is to complete the signal selection. And pre-amplification, in addition to the volume and sound effects for various adjustments and controls. In order to better perform frequency equalization and timbre beautification, the graphic equalizer is also separately input. This part is the "control center" of the entire broadcast sound system.
The power amplifier amplifies the signal from the preamplifier or the mixer, and then pushes the speaker through the transmission line. Although the transmission line is simple, it has different requirements depending on the system and transmission mode. For the auditorium, theater, etc., because the distance between the power amplifier and the speaker is not far, the direct feeding method of low resistance and large current is generally adopted, and the transmission line is required. Dedicated speaker cable, and for the public broadcasting system , because of the wide service area and long distance, in order to reduce the loss caused by the transmission line, the high-voltage transmission method is often adopted, and the transmission line is not required because of the small transmission current.
Speaker System: The speaker system requires the entire system to be matched, and the choice of its position should be realistic. Auditoriums, theaters, dance halls, sound quality, sound quality requirements, and speakers generally use high-power speakers; and public broadcasting systems , because it is not so high requirements for sound, generally use 3W-6W ceiling speakers is good;
Characteristics of the broadcasting system:
The background music is abbreviated as BCM. It is the abbreviation of BACK GROUD MUSIC. Its main function is to cover up the noise and create a relaxed and harmonious atmosphere. If the listener does not concentrate on listening, he can't distinguish the location of the sound source. The volume is small. A music that creates a relaxed and pleasant atmosphere. Therefore, there are two effects of background music. One is to cover up the environmental noise psychologically, and the other is to create an atmosphere that suits the indoor environment. It is widely used in hotels, hotels, restaurants, shopping malls, hospitals, office buildings and so on. It is not appropriate for a piece of music to be lyrical or to be easily intense.
Background music is not stereo, but mono music. This is because stereo requirements can distinguish the sound source orientation and have a sense of depth, while background music is not conscious to hear where the sound comes from, and does not want The location of the sound source is felt, and the sound source is required to be concealed, and the volume is lighter, so as not to affect the two people's opposite speech.
Characteristics of the fire broadcast function: Fire broadcast is activated when an accident occurs, so it is closely related to personal safety.
Therefore, fire broadcasting has the following characteristics:
The fire alarm signal should have the highest priority in the system, and it can cut off the status of background music and calling people. It should be operated by the fire alarm officer. Transmission cables and speakers should be fire resistant. In the case of AC power outage, the alarm broadcast should also be implemented.
1. General order of public broadcasting engineering design The public broadcasting mentioned here refers to the sound broadcasting of cable transmission, which is usually used in public places, buildings, and communities, for background music broadcasting, paging broadcasting, and forced insertion of forced broadcasting. .
The design of this type of public broadcasting project is usually carried out in the following order:
First of all, we should consider the selection and configuration of broadcast speakers, the selection of broadcast power amplifiers, and broadcast partitions.
2. Selection and configuration of broadcast speakers: Selection of broadcast speakers: In principle, broadcast speakers of different specifications should be selected depending on the environment. For example, in a room with a ceiling ceiling, an embedded, back coverless ceiling speaker should be used. Such as the CH-705 series. This type of speaker has a simple structure, is relatively inexpensive, and is easy to construct. The main disadvantage is that there is no back cover and it is easy to be bitten by insects and rats.
In indoors with only ceilings and no ceilings (such as open-frame shopping malls), ceiling-mounted tubular speakers (ST-708S) or ceiling speakers with rear cover (such as the XT-701N~705 series) should be used. Since the ceiling is equivalent to an infinite baffle, the use of a speaker without a rear cover in the case of a ceiling is not caused by an acoustic short circuit. The situation is very different when there is no ceiling. If you still use a ceilingless speaker without a back cover, the effect will be very poor. In this case, the lifting speaker is used in principle. However, if the investment is too large, a ceiling speaker with a rear cover can also be used. The rear cover with the rear cover ceiling speaker not only has the general mechanical protection effect, but also plays a role in preventing the acoustic short circuit to a certain extent.
In ceiling-free rooms (such as underground parking lots), wall-mounted speakers or indoor sound columns should be used. The former is BG-105, BG-106, BG-108 series, and the latter is SN-302~304 series.
Outdoors, an outdoor sound column or horn should be used. The former is SY-510~540, SY-611~616 series: the latter is like HS-30Q~150Q series. Such sound columns and horns not only have a rainproof function but also a large volume. Since the outdoor environment is empty and there is no reverberation effect, it is necessary to select a variety with a loud volume.
In gardens and grasslands, grass speakers should be used. Such as S-601~S-1001, KT-620, DT-21A~28A series. These speakers are rainproof, sleek, and the volume and sound quality are more elegant.
In the halls with high decoration and high ceilings, it is advisable to use hoisting speakers with elegant shape and harmonious color tone, such as ST-708S series. In the occasions with high arson requirements, arson-type speakers should be used. For example, the ST-708S series. This type of speaker is fully sealed and its outlet is mated to the flame-retardant sleeve.
3. Configuration of the broadcast speaker In principle, the broadcast speaker is arranged in the broadcast service area in a uniform and scattered manner, and the degree of dispersion should ensure that the signal-to-noise ratio in the service area is not less than 15DB. Generally, the noise floor of a high-grade office corridor is about 48~52DB, the noise floor of a super mall is about 58~63DB, and the noise floor of a busy road section is about 70~75DB. Considering the accident, the scene may be very confusing, so for the need of emergency broadcasting, even if the broadcasting service area is an office building, do not estimate the noise floor too low. For this reason, as a general consideration, in addition to the bustling and lively places, it is possible to roughly consider the noise floor as 65~70DB (except in special cases). According to this calculation, the sound pressure level of the broadcast coverage area should be above 80~85DB.
Since broadcast speakers are typically distributed, the sound pressure level of the broadcast coverage area can be approximated as a contribution from a single broadcast speaker. According to the relevant electroacoustic theory, the sound pressure level SPL of the speaker coverage area has the following relationship with the sensitivity level LM of the speaker, the electric power P fed to the speaker, and the distance R between the listening point and the speaker:
SPL=LM+10LgP-20Lgrdb(1)
The sensitivity level of the ceiling speaker is between 88~93DB: the rated power is 3~10W. At 90 DB/8W, the sound pressure level at the speaker BM is about 81 DB. The above does not consider the contribution of the early reflection sound group. Indoors, the contribution of early reflections and adjacent speakers can increase the sound pressure level by about 2~3DB.
According to the above approximate calculation, in the venue where the ceiling is not higher than 3M, the ceiling speakers can be uniformly arranged from each other by 5~8M. If only background music is considered without considering emergency broadcast, the distance can be increased to 8~12M. In addition, the fire accident design and installation specifications applicable to mainland China (hereinafter referred to as “Specifications:â€) have the following rigid rules: “The number of speakers in public places such as walkways, halls, restaurants, etc. should be guaranteed from any part of the floor. Recently, a speaker has a walking distance of no more than 15M. Speakers should be provided at the intersection of the walkway and at the corner. The last speaker at the end of the walkway is no more than 8M from the wall."
There is basically no early reflection sound group in outdoor places, and the effective coverage of a single broadcast speaker can only take the lower limit calculated above. Since the distance corresponding to the lower limit is very short, a sound column composed of a plurality of speakers should be used in principle. The signal power level fed to the speaker group (eg, the sound column) is doubled (provided the group is acceptable), and the sound pressure level can be increased by 3DB. Please pay attention to the meaning of "double". It is doubled from 1 to 2, and it is only twice as important as 2. In addition, for every 1 time increase in distance, the sound pressure level will drop by 6DB. According to the above rules, it is not difficult to estimate the arrangement distance of the outdoor sound column. For example, taking the CS-540 outdoor sound column as an example, its rated power is 40W, which is more than 4 times that of a single ceiling speaker. Therefore, its effective coverage distance is more than twice that of a single ceiling speaker. In fact, this distance can be larger. Because the sensitivity of the column is higher than that of a single ceiling speaker (about 3~6DB), the distance can be doubled for each additional point DB. That is to say, the coverage distance of the 540-sound column can reach 20M or more, but the radiation angle of the sound column is relatively narrow, and it is effective only about 60 to 90 degrees (horizontal angle) in front of it. The specific calculation can be obtained by equation (1).
The choice of broadcast power amplifiers is different from HI-FI power amplifiers. Its main feature is the 70V and 100V constant voltage output terminals. This is because broadcast lines are usually quite long and high-voltage transmission is required to reduce line loss. The most important indicator of a broadcast power amplifier is the rated output power, and the maximum rated output power should be selected, depending on the total power of the broadcast speaker.
For the broadcast system, as long as the total power of the broadcast speaker is less than or equal to the rated power of the power amplifier, and the voltage parameters are the same, it can be arbitrarily matched, but considering the line loss, aging and other factors, the power margin should be left as appropriate. According to the requirements of the "Specifications", the capacity of the power amplifier equipment (equivalent to the rated output power) should generally be calculated as follows:
P=K1.K2.P0∑(2)
P--power amplifier equipment output total electric power (W) P0--each branch (equivalent to partition) simultaneous broadcast maximum electric power P0=KI-PIPI--the first partition speaker rated capacity KI--the first partition requires the coefficient at the same time Service broadcast room program, take 0.2~0.4 background music system, take 0.5~0.6 business broadcast, take 0.7~0.8 fire accident broadcast, take 1.0K1--line attenuation compensation coefficient: 1.26~1.58K2--aging coefficient: 1.2~1.4 According to this, if it is a background music system, the rated output power of the broadcast power amplifier should be about 1.3 times of the total power of the broadcast speaker.
However, all public address systems should, in principle, be able to carry out emergency broadcasts of disasters. Therefore, the system must be equipped with an emergency broadcast amplifier. According to the "Specifications" requirements, the rated output power of the emergency broadcast power amplifier should be 1.5 times the sum of the speaker capacity of the three partitions with the largest capacity of the broadcast speaker. Broadcasting a public broadcasting system is usually divided into several areas, by the management (or Programs) determine which areas must be broadcast, those areas must be suspended, those areas must be inserted into emergency broadcasts, and so on.
The partitioning scheme depends in principle on the needs of the customer. Generally refer to the following rules:
1. Buildings are usually divided into floors. Shopping malls and amusement parks are usually divided by departments. Sports venues are usually divided into stands, residential quarters, resorts usually divided by property management, and so on.
2. The administrative department and the public place should be divided into districts.
3. A separate community where important departments or broadcast speakers have to be arbitrarily adjusted by field personnel. In short, the partition is for ease of management. Any part that needs to be treated separately should be divided into different areas. However, the total power of the broadcast speakers in each zone should not be too large, and it must be compatible with the capacity of the partitioner and the power amplifier. Take the PAS-2013D partitioner in the SYB series as an example. The power capacity of each zone is 500VA, but 10 The total capacity of the districts should not exceed 1000 VA. Accordingly, if 10 zones are operated at full capacity, the average zone should not exceed 100 VA (approximately 100 W).
Community Public Address System Structure The residential community public address system structure consists of four parts:
Broadcast power amplifier, audio input/output, sound equipment, and intelligent playback. The four are organically integrated into a unified public address system . The design of the structure fully takes into account the needs of the community for the function, but also pays attention to the construction cost of the system.
The broadcasting and sound system covers a wide range, from factories, schools, hotels, stations, terminals, plazas to venues, theaters, stadiums, residential quarters, etc.
In civil construction engineering design, broadcasting systems can be divided into the following categories:
Public broadcasting systems for public areas (squares, stations, terminals, shopping malls, restaurants, corridors, classrooms, etc.) and parking lots. This type of system is mainly used for voice broadcasting, so clarity is paramount. Moreover, such systems often broadcast background music in peacetime, and can be converted to emergency broadcasts in the event of a disaster or emergency.
Broadcast sound system for hotel rooms. Such systems include room audio broadcasts and emergency broadcasts, often delivered by bedside tables located in the guest rooms. The room broadcasts contain a number of freely selectable bands. In the case of emergency broadcasts, room broadcasts are automatically interrupted and automatically switched to emergency broadcasts.
Hall sound reinforcement system represented by auditorium, theater and gymnasium. This is a professional sound reinforcement system, which not only considers electro-acoustic technology problems, but also involves architectural acoustics. Both of them must be balanced and not neglected. Such broadcast systems often have comprehensive multi-purpose requirements, which can be used not only for the sound reinforcement of the venue language, but also for the performances of the arts. For large-scale live sound systems, the electric power is low. Tens of thousands, more than tens of thousands of watts, it is necessary to use high-powered speakers and power amplifiers, in the system configuration and equipment selection have certain requirements, while paying attention to the load of the power line.
Broadcast sound system for conference rooms, lecture halls, etc. Such systems are generally also systems that are set up for background music and emergency broadcasts provided by public broadcasts, but because of their particularity, conference broadcast systems are often set up separately in conference rooms and lecture halls. For higher requirements or international conference halls, special audiovisual systems such as simultaneous interpretation systems, conference voting systems, and large-screen projection televisions are also required.
As can be seen from the above, the broadcast audio systems for various buildings, hotels and other civil buildings can be basically classified into three types:
First, the public address system , this social cable broadcasting system, which includes background music and emergency broadcast functions, usually combined, usually play background music or other programs, and when an emergency such as a fire occurs, it is converted into an alarm broadcast. The microphone used for broadcasting in such a system is generally not in the same room as the speaker broadcasted to the public, so there is no problem of acoustic feedback, and the constant pressure transmission method is a typical system;
Second, the hall sound reinforcement system, this system uses professional audio equipment, and requires a high-powered speaker system and power amplifier, because the microphone and the speaker for sound reinforcement are in the same hall, there is the problem of acoustic feedback and even howling. And because of its short distance, the system generally uses low-impedance direct transmission; Third, the dedicated conference system, although it is also a sound reinforcement system, but has its special requirements, like the sound interpretation system.
The composition of a broadcast sound system <br> Regardless of which broadcast sound system, it can be divided into four parts: program equipment, signal amplification and processing equipment, transmission lines and speaker systems. Program source equipment: The program source is usually provided by radio broadcasting, laser phonograph and recording deck, in addition to microphones and electronic musical instruments.
Signal amplification and processing equipment: including mixers, preamplifiers, power amplifiers and various controllers and audio processing equipment. The primary task of this part of the equipment is signal amplification, followed by signal selection, the mixer and preamplifier have similar roles and status (of course, the mixer has higher function and performance indicators), and their basic function is to complete the signal selection. And pre-amplification, in addition to the volume and sound effects for various adjustments and controls. In order to better perform frequency equalization and timbre beautification, the graphic equalizer is also separately input. This part is the "control center" of the entire broadcast sound system.
The power amplifier amplifies the signal from the preamplifier or the mixer, and then pushes the speaker through the transmission line. Although the transmission line is simple, it has different requirements depending on the system and transmission mode. For the auditorium, theater, etc., because the distance between the power amplifier and the speaker is not far, the direct feeding method of low resistance and large current is generally adopted, and the transmission line is required. Dedicated speaker cable, and for the public broadcasting system , because of the wide service area and long distance, in order to reduce the loss caused by the transmission line, the high-voltage transmission method is often adopted, and the transmission line is not required because of the small transmission current.
Speaker System: The speaker system requires the entire system to be matched, and the choice of its position should be realistic. Auditoriums, theaters, dance halls, sound quality, sound quality requirements, and speakers generally use high-power speakers; and public broadcasting systems , because it is not so high requirements for sound, generally use 3W-6W ceiling speakers is good;
Characteristics of the broadcasting system:
The background music is abbreviated as BCM. It is the abbreviation of BACK GROUD MUSIC. Its main function is to cover up the noise and create a relaxed and harmonious atmosphere. If the listener does not concentrate on listening, he can't distinguish the location of the sound source. The volume is small. A music that creates a relaxed and pleasant atmosphere. Therefore, there are two effects of background music. One is to cover up the environmental noise psychologically, and the other is to create an atmosphere that suits the indoor environment. It is widely used in hotels, hotels, restaurants, shopping malls, hospitals, office buildings and so on. It is not appropriate for a piece of music to be lyrical or to be easily intense.
Background music is not stereo, but mono music. This is because stereo requirements can distinguish the sound source orientation and have a sense of depth, while background music is not conscious to hear where the sound comes from, and does not want The location of the sound source is felt, and the sound source is required to be concealed, and the volume is lighter, so as not to affect the two people's opposite speech.
Characteristics of the fire broadcast function: Fire broadcast is activated when an accident occurs, so it is closely related to personal safety.
Therefore, fire broadcasting has the following characteristics:
The fire alarm signal should have the highest priority in the system, and it can cut off the status of background music and calling people. It should be operated by the fire alarm officer. Transmission cables and speakers should be fire resistant. In the case of AC power outage, the alarm broadcast should also be implemented.
1. General order of public broadcasting engineering design The public broadcasting mentioned here refers to the sound broadcasting of cable transmission, which is usually used in public places, buildings, and communities, for background music broadcasting, paging broadcasting, and forced insertion of forced broadcasting. .
The design of this type of public broadcasting project is usually carried out in the following order:
First of all, we should consider the selection and configuration of broadcast speakers, the selection of broadcast power amplifiers, and broadcast partitions.
2. Selection and configuration of broadcast speakers: Selection of broadcast speakers: In principle, broadcast speakers of different specifications should be selected depending on the environment. For example, in a room with a ceiling ceiling, an embedded, back coverless ceiling speaker should be used. Such as the CH-705 series. This type of speaker has a simple structure, is relatively inexpensive, and is easy to construct. The main disadvantage is that there is no back cover and it is easy to be bitten by insects and rats.
In indoors with only ceilings and no ceilings (such as open-frame shopping malls), ceiling-mounted tubular speakers (ST-708S) or ceiling speakers with rear cover (such as the XT-701N~705 series) should be used. Since the ceiling is equivalent to an infinite baffle, the use of a speaker without a rear cover in the case of a ceiling is not caused by an acoustic short circuit. The situation is very different when there is no ceiling. If you still use a ceilingless speaker without a back cover, the effect will be very poor. In this case, the lifting speaker is used in principle. However, if the investment is too large, a ceiling speaker with a rear cover can also be used. The rear cover with the rear cover ceiling speaker not only has the general mechanical protection effect, but also plays a role in preventing the acoustic short circuit to a certain extent.
In ceiling-free rooms (such as underground parking lots), wall-mounted speakers or indoor sound columns should be used. The former is BG-105, BG-106, BG-108 series, and the latter is SN-302~304 series.
Outdoors, an outdoor sound column or horn should be used. The former is SY-510~540, SY-611~616 series: the latter is like HS-30Q~150Q series. Such sound columns and horns not only have a rainproof function but also a large volume. Since the outdoor environment is empty and there is no reverberation effect, it is necessary to select a variety with a loud volume.
In gardens and grasslands, grass speakers should be used. Such as S-601~S-1001, KT-620, DT-21A~28A series. These speakers are rainproof, sleek, and the volume and sound quality are more elegant.
In the halls with high decoration and high ceilings, it is advisable to use hoisting speakers with elegant shape and harmonious color tone, such as ST-708S series. In the occasions with high arson requirements, arson-type speakers should be used. For example, the ST-708S series. This type of speaker is fully sealed and its outlet is mated to the flame-retardant sleeve.
3. Configuration of the broadcast speaker In principle, the broadcast speaker is arranged in the broadcast service area in a uniform and scattered manner, and the degree of dispersion should ensure that the signal-to-noise ratio in the service area is not less than 15DB. Generally, the noise floor of a high-grade office corridor is about 48~52DB, the noise floor of a super mall is about 58~63DB, and the noise floor of a busy road section is about 70~75DB. Considering the accident, the scene may be very confusing, so for the need of emergency broadcasting, even if the broadcasting service area is an office building, do not estimate the noise floor too low. For this reason, as a general consideration, in addition to the bustling and lively places, it is possible to roughly consider the noise floor as 65~70DB (except in special cases). According to this calculation, the sound pressure level of the broadcast coverage area should be above 80~85DB.
Since broadcast speakers are typically distributed, the sound pressure level of the broadcast coverage area can be approximated as a contribution from a single broadcast speaker. According to the relevant electroacoustic theory, the sound pressure level SPL of the speaker coverage area has the following relationship with the sensitivity level LM of the speaker, the electric power P fed to the speaker, and the distance R between the listening point and the speaker:
SPL=LM+10LgP-20Lgrdb(1)
The sensitivity level of the ceiling speaker is between 88~93DB: the rated power is 3~10W. At 90 DB/8W, the sound pressure level at the speaker BM is about 81 DB. The above does not consider the contribution of the early reflection sound group. Indoors, the contribution of early reflections and adjacent speakers can increase the sound pressure level by about 2~3DB.
According to the above approximate calculation, in the venue where the ceiling is not higher than 3M, the ceiling speakers can be uniformly arranged from each other by 5~8M. If only background music is considered without considering emergency broadcast, the distance can be increased to 8~12M. In addition, the fire accident design and installation specifications applicable to mainland China (hereinafter referred to as “Specifications:â€) have the following rigid rules: “The number of speakers in public places such as walkways, halls, restaurants, etc. should be guaranteed from any part of the floor. Recently, a speaker has a walking distance of no more than 15M. Speakers should be provided at the intersection of the walkway and at the corner. The last speaker at the end of the walkway is no more than 8M from the wall."
There is basically no early reflection sound group in outdoor places, and the effective coverage of a single broadcast speaker can only take the lower limit calculated above. Since the distance corresponding to the lower limit is very short, a sound column composed of a plurality of speakers should be used in principle. The signal power level fed to the speaker group (eg, the sound column) is doubled (provided the group is acceptable), and the sound pressure level can be increased by 3DB. Please pay attention to the meaning of "double". It is doubled from 1 to 2, and it is only twice as important as 2. In addition, for every 1 time increase in distance, the sound pressure level will drop by 6DB. According to the above rules, it is not difficult to estimate the arrangement distance of the outdoor sound column. For example, taking the CS-540 outdoor sound column as an example, its rated power is 40W, which is more than 4 times that of a single ceiling speaker. Therefore, its effective coverage distance is more than twice that of a single ceiling speaker. In fact, this distance can be larger. Because the sensitivity of the column is higher than that of a single ceiling speaker (about 3~6DB), the distance can be doubled for each additional point DB. That is to say, the coverage distance of the 540-sound column can reach 20M or more, but the radiation angle of the sound column is relatively narrow, and it is effective only about 60 to 90 degrees (horizontal angle) in front of it. The specific calculation can be obtained by equation (1).
The choice of broadcast power amplifiers is different from HI-FI power amplifiers. Its main feature is the 70V and 100V constant voltage output terminals. This is because broadcast lines are usually quite long and high-voltage transmission is required to reduce line loss. The most important indicator of a broadcast power amplifier is the rated output power, and the maximum rated output power should be selected, depending on the total power of the broadcast speaker.
For the broadcast system, as long as the total power of the broadcast speaker is less than or equal to the rated power of the power amplifier, and the voltage parameters are the same, it can be arbitrarily matched, but considering the line loss, aging and other factors, the power margin should be left as appropriate. According to the requirements of the "Specifications", the capacity of the power amplifier equipment (equivalent to the rated output power) should generally be calculated as follows:
P=K1.K2.P0∑(2)
P--power amplifier equipment output total electric power (W) P0--each branch (equivalent to partition) simultaneous broadcast maximum electric power P0=KI-PIPI--the first partition speaker rated capacity KI--the first partition requires the coefficient at the same time Service broadcast room program, take 0.2~0.4 background music system, take 0.5~0.6 business broadcast, take 0.7~0.8 fire accident broadcast, take 1.0K1--line attenuation compensation coefficient: 1.26~1.58K2--aging coefficient: 1.2~1.4 According to this, if it is a background music system, the rated output power of the broadcast power amplifier should be about 1.3 times of the total power of the broadcast speaker.
However, all public address systems should, in principle, be able to carry out emergency broadcasts of disasters. Therefore, the system must be equipped with an emergency broadcast amplifier. According to the "Specifications" requirements, the rated output power of the emergency broadcast power amplifier should be 1.5 times the sum of the speaker capacity of the three partitions with the largest capacity of the broadcast speaker. Broadcasting a public broadcasting system is usually divided into several areas, by the management (or Programs) determine which areas must be broadcast, those areas must be suspended, those areas must be inserted into emergency broadcasts, and so on.
The partitioning scheme depends in principle on the needs of the customer. Generally refer to the following rules:
1. Buildings are usually divided into floors. Shopping malls and amusement parks are usually divided by departments. Sports venues are usually divided into stands, residential quarters, resorts usually divided by property management, and so on.
2. The administrative department and the public place should be divided into districts.
3. A separate community where important departments or broadcast speakers have to be arbitrarily adjusted by field personnel. In short, the partition is for ease of management. Any part that needs to be treated separately should be divided into different areas. However, the total power of the broadcast speakers in each zone should not be too large, and it must be compatible with the capacity of the partitioner and the power amplifier. Take the PAS-2013D partitioner in the SYB series as an example. The power capacity of each zone is 500VA, but 10 The total capacity of the districts should not exceed 1000 VA. Accordingly, if 10 zones are operated at full capacity, the average zone should not exceed 100 VA (approximately 100 W).
Community Public Address System Structure The residential community public address system structure consists of four parts:
Broadcast power amplifier, audio input/output, sound equipment, and intelligent playback. The four are organically integrated into a unified public address system . The design of the structure fully takes into account the needs of the community for the function, but also pays attention to the construction cost of the system.
The broadcasting and sound system covers a wide range, from factories, schools, hotels, stations, terminals, plazas to venues, theaters, stadiums, residential quarters, etc.
In civil construction engineering design, broadcasting systems can be divided into the following categories:
Public broadcasting systems for public areas (squares, stations, terminals, shopping malls, restaurants, corridors, classrooms, etc.) and parking lots. This type of system is mainly used for voice broadcasting, so clarity is paramount. Moreover, such systems often broadcast background music in peacetime, and can be converted to emergency broadcasts in the event of a disaster or emergency.
Broadcast sound system for hotel rooms. Such systems include room audio broadcasts and emergency broadcasts, often delivered by bedside tables located in the guest rooms. The room broadcasts contain a number of freely selectable bands. In the case of emergency broadcasts, room broadcasts are automatically interrupted and automatically switched to emergency broadcasts.
Hall sound reinforcement system represented by auditorium, theater and gymnasium. This is a professional sound reinforcement system, which not only considers electro-acoustic technology problems, but also involves architectural acoustics. Both of them must be balanced and not neglected. Such broadcast systems often have comprehensive multi-purpose requirements, which can be used not only for the sound reinforcement of the venue language, but also for the performances of the arts. For large-scale live sound systems, the electric power is low. Tens of thousands, more than tens of thousands of watts, it is necessary to use high-powered speakers and power amplifiers, in the system configuration and equipment selection have certain requirements, while paying attention to the load of the power line.
Broadcast sound system for conference rooms, lecture halls, etc. Such systems are generally also systems that are set up for background music and emergency broadcasts provided by public broadcasts, but because of their particularity, conference broadcast systems are often set up separately in conference rooms and lecture halls. For higher requirements or international conference halls, special audiovisual systems such as simultaneous interpretation systems, conference voting systems, and large-screen projection televisions are also required.
As can be seen from the above, the broadcast audio systems for various buildings, hotels and other civil buildings can be basically classified into three types:
First, the public address system , this social cable broadcasting system, which includes background music and emergency broadcast functions, usually combined, usually play background music or other programs, and when an emergency such as a fire occurs, it is converted into an alarm broadcast. The microphone used for broadcasting in such a system is generally not in the same room as the speaker broadcasted to the public, so there is no problem of acoustic feedback, and the constant pressure transmission method is a typical system;
Second, the hall sound reinforcement system, this system uses professional audio equipment, and requires a high-powered speaker system and power amplifier, because the microphone and the speaker for sound reinforcement are in the same hall, there is the problem of acoustic feedback and even howling. And because of its short distance, the system generally uses low-impedance direct transmission; Third, the dedicated conference system, although it is also a sound reinforcement system, but has its special requirements, like the sound interpretation system.
广æ’音å“ç³»ç»Ÿçš„ç»„æˆ <br> ä¸ç®¡å“ªä¸€ç§å¹¿æ’音å“系统，它基本å¯åˆ†å››ä¸ªéƒ¨åˆ†ï¼šèŠ‚目设备ã€ä¿¡å·çš„放大和处ç†è®¾å¤‡ã€ä¼ 输线路和扬声器系统。节目æºè®¾å¤‡ï¼šèŠ‚ç›®æºé€šå¸¸ä¸ºæ— 线电广æ’，激光唱机和录音å¡åº§ç‰è®¾å¤‡æ供，æ¤å¤–è¿˜æœ‰ä¼ å£°å™¨ã€ç”µåä¹å™¨ç‰ã€‚
ä¿¡å·æ”¾å¤§å’Œå¤„ç†è®¾å¤‡ï¼šåŒ…括调音å°ã€å‰ç½®æ”¾å¤§å™¨ã€åŠŸçŽ‡æ”¾å¤§å™¨å’Œå„ç§æŽ§åˆ¶å™¨åŠéŸ³å“åŠ å·¥è®¾å¤‡ç‰ã€‚这部分设备的首è¦ä»»åŠ¡æ˜¯ä¿¡å·æ”¾å¤§ï¼Œå…¶æ¬¡æ˜¯ä¿¡å·çš„选择，调音å°å’Œå‰ç½®æ”¾å¤§å™¨ä½œç”¨å’Œåœ°ä½ç›¸ä¼¼ï¼ˆå½“然调音å°çš„åŠŸèƒ½å’Œæ€§èƒ½æŒ‡æ ‡æ›´é«˜ï¼‰ï¼Œå®ƒä»¬çš„åŸºæœ¬åŠŸèƒ½æ˜¯å®Œæˆä¿¡å·çš„选择和å‰ç½®æ”¾å¤§ï¼Œæ¤å¤–还担负音é‡å’ŒéŸ³å“效果进行å„ç§è°ƒæ•´å’ŒæŽ§åˆ¶ã€‚有时为了更好地进行频率å‡è¡¡å’ŒéŸ³è‰²ç¾ŽåŒ–，还å¦å¤–å•ç‹¬æŠ•å…¥å›¾ç¤ºå‡è¡¡å™¨ã€‚这部分是整个广æ’音å“系统的“控制ä¸å¿ƒâ€ã€‚
功率放大器则将å‰ç½®æ”¾å¤§å™¨æˆ–调音å°é€æ¥çš„ä¿¡å·è¿›è¡ŒåŠŸçŽ‡æ”¾å¤§ï¼Œå†é€šè¿‡ä¼ è¾“çº¿åŽ»æŽ¨åŠ¨æ‰¬å£°å™¨æ”¾å£°ã€‚ä¼ è¾“çº¿è·¯è™½ç„¶ç®€å•ï¼Œä½†éšç€ç³»ç»Ÿå’Œä¼ 输方å¼çš„ä¸åŒè€Œæœ‰ä¸åŒçš„è¦æ±‚ï¼Œå¯¹ç¤¼å ‚ã€å‰§åœºç‰ï¼Œç”±äºŽåŠŸçŽ‡æ”¾å¤§å™¨ä¸Žæ‰¬å£°å™¨çš„è·ç¦»ä¸è¿œï¼Œä¸€èˆ¬é‡‡ç”¨ä½Žé˜»å¤§ç”µæµçš„直接馈é€æ–¹å¼ï¼Œä¼ 输线è¦æ±‚用专用喇å线，而对公共广æ’系统 ，由于æœåŠ¡åŒºåŸŸå¹¿ï¼Œè·ç¦»é•¿ï¼Œä¸ºäº†å‡å°‘ä¼ è¾“çº¿è·¯å¼•èµ·çš„æŸè€—ï¼Œå¾€å¾€é‡‡ç”¨é«˜åŽ‹ä¼ è¾“æ–¹å¼ï¼Œç”±äºŽä¼ 输电æµå°ï¼Œæ•…å¯¹ä¼ è¾“çº¿è¦æ±‚ä¸é«˜ã€‚
扬声器系统：扬声器系统è¦æ±‚整个系统è¦åŒ¹é…，åŒæ—¶å…¶ä½ç½®çš„选择也è¦åˆ‡åˆå®žé™…ã€‚ç¤¼å ‚ã€å‰§åœºã€æŒèˆžåŽ…音色ã€éŸ³è´¨è¦æ±‚高，而扬声器一般用大功率音箱；而公共广æ’系统 ，由于它对音色è¦æ±‚ä¸æ˜¯é‚£ä¹ˆé«˜ï¼Œä¸€èˆ¬ç”¨3W-6W天花喇åå³å¥½ï¼›
广æ’系统的特点：
背景音ä¹ç®€ç§°BCM，是BACK GROUD MUSIC的缩写，它的主è¦ä½œç”¨æ˜¯æŽ©ç›–å™ªå£°å¹¶åˆ›é€ ä¸€ä¸è½»æ¾å’Œè°çš„气氛，å¬çš„人若ä¸ä¸“心å¬ï¼Œå°±ä¸èƒ½è¾¨åˆ«å…¶å£°æºä½ç½®ï¼ŒéŸ³é‡è¾ƒå°ï¼Œæ˜¯ä¸€ç§èƒ½åˆ›é€ è½»æ¾æ„‰å¿«çŽ¯å¢ƒæ°”氛的音ä¹ã€‚å› æ¤ï¼ŒèƒŒæ™¯éŸ³ä¹çš„效果有两个，一是心ç†ä¸ŠæŽ©ç›–çŽ¯å¢ƒå™ªå£°ï¼ŒäºŒæ˜¯åˆ›é€ ä¸Žå®¤å†…çŽ¯å¢ƒç›¸é€‚åº”çš„æ°”æ°›ï¼Œå®ƒåœ¨å®¾é¦†ã€é…’店ã€é¤åŽ…ã€å•†åœºã€åŒ»é™¢ã€åŠžå…¬æ¥¼ç‰å¹¿æ³›çš„应用。ä¹æ›²åº”æ˜¯æŠ’æƒ…é£Žæ ¼çš„æˆ–æ˜¯è½»æ¾çš„强烈激性的ä¹æ›²æ˜¯ä¸é€‚宜。
背景音ä¹ä¸æ˜¯ç«‹ä½“声，而是å•å£°é“音ä¹ï¼Œè¿™æ˜¯å› 为立体声è¦æ±‚能分辨出声æºæ–¹ä½ï¼Œå¹¶ä¸”有纵深感，而背景音ä¹åˆ™æ˜¯ä¸ä¸“心å¬å°±æ„识ä¸åˆ°å£°éŸ³ä»Žä½•å¤„æ¥ï¼Œå¹¶ä¸å¸Œæœ›ä¸ºäººæ„Ÿè§‰å‡ºå£°æºçš„ä½ç½®ï¼Œä»¥è‡³è¦æ±‚把声æºéšè”½èµ·æ¥ï¼Œè€ŒéŸ³é‡è¦è¾ƒè½»ï¼Œä»¥ä¸å½±å“两人对é¢è®²è¯ä¸ºåŽŸåˆ™ã€‚
消防广æ’功能的特点：消防广æ’是在有事故å‘生时å¯ç”¨ï¼Œæ‰€ä»¥å®ƒè·Ÿäººèº«çš„安全有密切关系.
å› è€Œæ¶ˆé˜²å¹¿æ’有以下特点：
消防报è¦ä¿¡å·åº”在系统ä¸å…·æœ‰æœ€é«˜ä¼˜å…ˆæƒï¼Œå¯å¯¹èƒŒæ™¯éŸ³ä¹å’Œå‘¼å«æ‰¾äººç‰çŠ¶æ€å…·æœ‰åˆ‡æ–功能。应使于消防报è¦å€¼ç人员æ“ä½œã€‚ä¼ è¾“ç”µç¼†å’Œæ‰¬å£°å™¨åº”å…·æœ‰é˜²ç«ç‰¹æ€§ã€‚在交æµç”µæ–电的情况下也è¦ä¿è¯æŠ¥è¦å¹¿æ’实施。
1ã€å…¬å…±å¹¿æ’工程设计的一般顺åºè¿™é‡Œæ‰€è¯´çš„公共广æ’æ˜¯æŒ‡æœ‰çº¿ä¼ è¾“çš„å£°éŸ³å¹¿æ’，通常用于公共场所ã€å¤§åŽ¦ã€å°åŒºå†…部，供背景音ä¹å¹¿æ’ã€å¯»å‘¼å¹¿æ’以åŠå¼ºè¡Œæ’入的ç¾å®³æ€§å¹¿æ’使用。
这一类公共广æ’工程的设计，通常按下列顺åºè¿›è¡Œï¼š
首先应考虑广æ’扬声器的选用ã€é…置，广æ’功放的选用，广æ’分区。
2ã€å¹¿æ’扬声器的选用和é…置广æ’扬声器的选用：原则上应视环境选用ä¸åŒå“ç§è§„æ ¼çš„å¹¿æ’扬声器。 For example, in a room with a ceiling ceiling, an embedded, back coverless ceiling speaker should be used.如CH-705系列。 This type of speaker has a simple structure, is relatively inexpensive, and is easy to construct. The main disadvantage is that there is no back cover and it is easy to be bitten by insects and rats.
在仅有框架åŠé¡¶è€Œæ— 天花æ¿çš„室内（如开架å¼å•†åœºï¼‰ï¼Œå®œç”¨åŠè£…å¼ç’型音箱（ST-708S）或有åŽç½©çš„天花扬声器（如XT-701N~705系列）。由于天花æ¿ç›¸å½“于一å—æ— é™å¤§çš„éšœæ¿ï¼Œæ‰€ä»¥è‡ªçˆ±æœ‰å¤©èŠ±æ¿çš„æ¡ä»¶ä¸‹ä½¿ç”¨æ— åŽç½©çš„扬声器也ä¸ä¼šå¼•èµ·å£°çŸè·¯ã€‚而没有天花æ¿æ—¶æƒ…况就大ä¸ç›¸åŒï¼Œå¦‚æžœä»ç”¨æ— åŽç½©çš„天花扬声器，效果会很差。这时原则上使用åŠè£…音箱。 However, if the investment is too large, a ceiling speaker with a rear cover can also be used.有åŽç½©å¤©èŠ±æ‰¬å£°å™¨çš„åŽç½©ä¸ä»…有一般的机械防护作用，而且在一定程度上起到防æ¢å£°çŸè·¯çš„作用。
åœ¨æ— åŠé¡¶çš„室内（例如地下åœè½¦åœºï¼‰ï¼Œåˆ™å®œé€‰ç”¨å£æŒ‚å¼æ‰¬å£°å™¨æˆ–室内音柱。å‰è€…如BG-105ã€BG-106ã€BG-108系列，åŽè€…如SN-302~304系列。
在室外，宜选用室外音柱或å·è§’。å‰è€…如SY-510~540ã€SY-611~616系列：åŽè€…如HS-30Q~150Q系列。这类音柱和å·è§’ä¸ä»…有防雨功能而且音é‡è¾ƒå¤§ï¼Œç”±äºŽå®¤å¤–环境空旷，没有混å“效应，选择音é‡è¾ƒå¤§çš„å“ç§æ˜¯å¿…须的。
In gardens and grasslands, grass speakers should be used.如S-601~S-1001ã€KT-620ã€DT-21A~28Aç‰ç³»åˆ—。 These speakers are rainproof, sleek, and the volume and sound quality are more elegant.
在装修讲究ã€é¡¶æ£šé«˜é˜”çš„åŽ…å ‚ï¼Œå®œé€‰ç”¨é€ åž‹ä¼˜é›…ã€è‰²è°ƒå’Œè°çš„åŠè£…å¼æ‰¬å£°å™¨ï¼Œå¦‚ST-708S系列，在放ç«è¦æ±‚较高的场åˆï¼Œå®œé€‰ç”¨æ”¾ç«åž‹çš„扬声器。例如ST-708S系列。 This type of speaker is fully sealed and its outlet is mated to the flame-retardant sleeve.
3ã€å¹¿æ’扬声器的é…置广æ’扬声器原则上以å‡åŒ€ã€åˆ†æ•£çš„原则é…置于广æ’æœåŠ¡åŒºï¼Œå…¶åˆ†æ•£çš„程度应ä¿è¯æœåŠ¡åŒºå†…的信噪比ä¸å°äºŽ15DB。 通常，高级写å—楼走廊的本底噪声约为48~52DB，超级商场的本底噪声约58~63DB，ç¹åŽè·¯æ®µçš„本底噪声约为70~75DB。考虑到å‘生事故时，现场å¯èƒ½ååˆ†æ··ä¹±ï¼Œå› æ¤ä¸ºäº†ç´§æ€¥å¹¿æ’的需è¦ï¼Œå³ä½¿å¹¿æ’æœåŠ¡åŒºæ˜¯å†™å—楼，也ä¸è¦æŠŠæœ¬åº•å™ªå£°ä¼°è®¡å¾—太低。æ¤æ¤ï¼Œä½œä¸ºä¸€èˆ¬è€ƒè™‘，除了ç¹åŽçƒé—¹çš„场所，ä¸å¦¨å¤§è‡´æŠŠæœ¬åº•å™ªå£°è§†ä¸º65~70DB（特殊情况除外）。照æ¤æŽ¨ç®—，广æ’覆盖区的声压级宜在80~85DB以上。
鉴于广æ’扬声器通常是分散é…置的，所以广æ’覆盖区的声压级å¯ä»¥è¿‘似地认为是å•ä¸ªå¹¿æ’æ‰¬å£°å™¨çš„è´¡çŒ®ã€‚æ ¹æ®æœ‰å…³çš„电声å¦ç†è®ºï¼Œæ‰¬å£°å™¨è¦†ç›–区的声压级SPLåŒæ‰¬å£°å™¨çš„çµæ•åº¦çº§LMã€é¦ˆç»™æ‰¬å£°å™¨çš„电功率Pã€å¬éŸ³ç‚¹ä¸Žæ‰¬å£°å™¨çš„è·ç¦»Rç‰æœ‰å¦‚下关系：
SPL=LM+10LgP-20Lgrdb（1）
天花扬声器的çµæ•åº¦çº§åœ¨88~93DB之间：é¢å®šåŠŸçŽ‡ä¸º3~10W。以90DB/8W算，在离扬声器BM处的声压级约为81DB。以上算未考虑早期å射声群的贡献。在室内，早期å射声群和邻近扬声器的贡献å¯ä½¿å£°åŽ‹çº§å¢žåŠ 2~3DBå·¦å³ã€‚
æ ¹æ®ä»¥ä¸Šè¿‘似计算，在天花æ¿ä¸é«˜äºŽ3M的场馆内，天花扬声器大体å¯ä»¥äº’相è·ç¦»5~8Må‡åŒ€é…置。如果仅考虑背景音ä¹è€Œä¸è€ƒè™‘紧急广æ’，则该è·ç¦»å¯ä»¥å¢žå¤§è‡³8~12M。å¦å¤–，适用于ä¸å›½å¤§é™†çš„ç«ç¾äº‹æ•…广æ’设计安装规范（以下简称“规范：）有以下一些硬性规定：“走é“ã€å¤§åŽ…ã€é¤åŽ…ç‰å…¬ä¼—场所，扬声器的é…置数é‡ï¼Œåº”能ä¿è¯ä»Žæœ¬å±‚任何部ä½åˆ°æœ€è¿‘一个扬声器的æ¥è¡Œè·ç¦»ä¸è¶…过15M。 Speakers should be provided at the intersection of the walkway and at the corner.èµ°é“末端最åŽä¸€ä¸ªæ‰¬å£°å™¨è·å¢™ä¸å¤§äºŽ8Mâ€ã€‚
There is basically no early reflection sound group in outdoor places, and the effective coverage of a single broadcast speaker can only take the lower limit calculated above. Since the distance corresponding to the lower limit is very short, a sound column composed of a plurality of speakers should be used in principle.馈给扬声器群组（例如音柱）的信å·ç”µåŠŸçŽ‡æ¯å¢žåŠ 一å€ï¼ˆå‰æ是该群组能够接å—），声压级å¯æå‡3DB。请注æ„“一å€â€çš„å«ä¹‰ã€‚ç”±1增至2是一å€ï¼Œè€Œç”±2增至关é‡è¦æ‰æ˜¯ä¸€å€ã€‚å¦å¤–，è·ç¦»æ¯å¢žåŠ 1å€ï¼Œå£°åŽ‹çº§å°†ä¸‹é™6DBã€‚æ ¹æ®ä¸Šè¿°è§„则ä¸éš¾æŽ¨ç®—室外音柱的é…ç½®è·ç¦»ã€‚例如，以CS-540室外音柱为例，其é¢å®šåŠŸçŽ‡ä¸º40W，是å•ä¸ªå¤©èŠ±æ‰¬å£°å™¨çš„4å€ä»¥ä¸Šã€‚ Therefore, its effective coverage distance is more than twice that of a single ceiling speaker.事实上，这个è·ç¦»è¿˜å¯ä»¥å¤§ä¸€äº›ã€‚å› ä¸ºéŸ³æŸ±çš„çµæ•åº¦æ¯”å•ä¸ªå¤©èŠ±æ‰¬å£°å™¨è¦é«˜ï¼ˆçº¦é«˜3~6DB），而æ¯å¢žåŠ 点DB，è·ç¦»å°±å¯å†åŠ å€ã€‚也就是说540音柱的覆盖è·ç¦»å¯ä»¥è¾¾20M以上，但音柱的è¾å°„角比较窄，仅在其æ£å‰æ–¹çº¦60~90度（水平角）左å³æœ‰æ•ˆã€‚具体计算å¯ç”¨å¼ï¼ˆ1）。
广æ’功放的选用广æ’功放ä¸åŒäºŽHI-FI功放，其最主è¦çš„特å¾æ˜¯å…·æœ‰70Vå’Œ100Væ’压输出端å，这是由于广æ’çº¿è·¯é€šå¸¸éƒ½ç›¸å½“é•¿ï¼Œé¡»ç”¨é«˜åŽ‹ä¼ è¾“æ‰èƒ½å‡å°‘线路æŸè€—。广æ’功放的最é‡è¦æŒ‡æ ‡æ˜¯é¢å®šè¾“出功率，应选用多大的é¢å®šè¾“出功率，须视广æ’扬声器的总功率而定。
对于广æ’系统æ¥è¯´ï¼Œåªè¦å¹¿æ’扬声器的总功率å°äºŽæˆ–ç‰äºŽåŠŸæ”¾çš„é¢å®šåŠŸçŽ‡ï¼Œè€Œä¸”电压å‚数相åŒï¼Œå³å¯éšæ„é…接，但考虑到线路æŸè€—ã€è€åŒ–ç‰å› ç´ ï¼Œåº”é€‚å½“ç•™æœ‰åŠŸçŽ‡ä½™é‡ã€‚按照“规范â€çš„è¦æ±‚，功放设备的容é‡ï¼ˆç›¸å½“于é¢å®šè¾“出功率）一般应按下å¼è®¡ç®—：
P=K1.K2.P0∑(2)
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分区方案原则上å–决客户的需è¦ã€‚通常å¯å‚考下列规则：
1ã€å¤§åŽ¦é€šå¸¸ä»¥æ¥¼å±‚分区，商场ã€æ¸¸ä¹åœºé€šå¸¸ä»¥éƒ¨é—¨åˆ†åŒºï¼Œè¿åŠ¨åœºé¦†é€šå¸¸ä»¥çœ‹å°åˆ†åŒºï¼Œä½å®…å°åŒºï¼Œåº¦å‡æ‘通常按物业管ç†åˆ†åŒºï¼Œç‰ç‰ã€‚
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广æ’功放ã€éŸ³æºè¾“å…¥/出ã€æ”¾å£°å™¨æã€æ™ºèƒ½æ’放。四者有机紧密地结åˆä¸ºä¸€ä¸ªç»Ÿä¸€çš„公共广æ’系统 。该结构的设计充分考虑到å°åŒºå¯¹åŠŸèƒ½çš„需求，åˆæ³¨é‡äº†ç³»ç»Ÿçš„å»ºé€ æˆæœ¬ã€‚
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