The sound field is as important as the cabinet of a speaker. A good sound stage will give full play to the advantages of audio equipment and appreciate it pleasantly; An unreasonable sound field will greatly reduce the performance level of the device and affect the sense of hearing. Of course, due to the limitation of the level of architectural decoration and the user's understanding of sound engineering, many projects contact the sound construction unit very late, so that the design of the sound field cannot be carried out completely, so that many sound projects lack sound field design.
A basic sound field design includes: the treatment of sound insulation, the reduction of on-site noise, the requirements of building structure, the realization of sound uniformity, the avoidance of problems such as sound chatter, focusing, feedback, etc., indoor calculation, etc. The following classification is analyzed.

In order to create a quiet sound field and avoid the impact on the units and residents in the surrounding environment, at the beginning of the sound field design, the treatment of sound insulation should first be considered in order to provide a good innate condition for the sound field, and the treatment of sound insulation involves the sound insulation between the building and the outside world, and the sound insulation of each room in the building. The parts of sound insulation include: sound insulation of partition walls, sound insulation of doors and windows, ceiling ceiling sound insulation of rooms connected at the top, etc.
For sound insulation with the outside world, the general building structure can meet the basic sound insulation requirements, but if the building design does not consider the needs of sound engineering at all, it is necessary to investigate the sound insulation situation, if necessary, you should consult with the architectural design unit and learn about the local noise restrictions from the public security organs. Usually do not use the height of the floor as sound engineering for sound insulation between rooms, if the wall is too thin, it will bring a certain difficulty to the project, this time to negotiate with the decoration unit to add a layer of partition to the wall when decorating to solve the medium and high frequency sound insulation.
Low-frequency sound insulation is more difficult to completely solve, because there is no more effective way than to increase the weight of the sound insulation.
Doors and windows are the weak link of sound insulation treatment, for their sound insulation can be recommended to the decoration unit to improve the production quality of doors and windows, if necessary, use leather doors and double-glazed windows, or add isolation passages outside the door and hang heavy double-layer curtains on the windows;
For the ceiling ceiling insulation of the top connected room is also more critical, especially in some large-scale entertainment venues built in recent years, the sound of the hall has a great impact on the surrounding private rooms, part of the interference is from the ceiling ceiling, this part of the sound insulation scheme can not be proposed too late, otherwise it is difficult to implement, so the sound designer is required to raise questions to the decoration unit as soon as possible and coordinate a feasible plan. For example: cover the ceiling with a layer of fireproof and sound-absorbing cotton or add another layer of ceiling at a certain distance above the ceiling.

In short, the sound insulation treatment of the project is of great significance, not only to improve the quality of the project but also to facilitate the normal use of users, and at the same time should pay attention to carefully consider whether the sound insulation treatment is necessary and whether the treatment method is feasible, otherwise it will increase some unnecessary work and costs.
Reduction of on-site noise Many people
do not pay attention to the background noise of the site, but in the relevant standards have put forward corresponding requirements, such as: the first-level cabaret should be less than 35dB, the first-level disco should be less than 40dB, the reason is: the increase of background noise correspondingly reduces the signal-to-noise ratio of the sound reinforcement system, affecting the quality of the project, in order to effectively solve this problem, the aforementioned sound insulation is limited. For example: whether the air outlet noise of the central air conditioner is solved by the installation unit; The noise, size, installation position of the exhaust fan, etc.
The general
sound is not capable of making the building structure completely designed according to its own intentions, but for the part of the project quality requirements that are strict and the construction project is processed on the reconstructed structure, it is necessary for the sound designer to put forward the corresponding requirements as much as possible. Here is mainly about some local structural conditions of the building: First of all, the construction unit must obtain the recognition of the load-bearing capacity of the wall or roof that needs to be hoisted in the sound project, especially when the weight of the lamp shed is large,
hoisting is more important;
Secondly, it is necessary to have a more detailed understanding of the room structure, embedded pipeline location and exit in the existing building, so as to facilitate the possible interspersed pipe and wiring construction;
The second is to understand the weak links in the internal structure of the building, and find out what the landlord can change and what cannot.
The realization of sound uniformity The concept
of sound uniformity is generally not very clear, and there is not much consideration in the project, is it not important? No, it's very important.
To give a simple example: you go to an entertainment hall and find that the sound situation is different everywhere, some places the music is very good, and some places seem to have shortcomings or something, and the sound is erratic. This is the effect of poor uniformity.

In the relevant standards, it is generally required that the deviation of the test value of the field pressure level at each point is less than 2dB.
How do you achieve a uniform sound stage?
First of all, there should be no obvious defects in the building structure. For example: there should not be too many columns in the room, and the wall should avoid arcs with traps, especially the wall on the side of the stage should not have a large structure; There can not be a large sound shadow area in the sound reinforcement range, but because a large number of changes cannot be made to meet these requirements after the decoration is completed in the later stage of the construction of the building structure, the experience should be used as much as possible in the sound engineering, the sound reinforcement area should be cleverly arranged, the larger defective structure should be avoided, and the impact brought by them should be minimized;
Secondly, some simple solutions to improve the sound diffusion effect can be provided to the decorative unit in a timely and effective manner. For example: all concert halls have a good sound diffusion effect, because its interior uses a large number of various shapes of sound diffusers, and these structures can be completed by some simple decorative methods, so as long as the method is proper should be able to achieve better results, of course, to the shape of the diffusion, position, quantity of reasonable and appropriate design is not an easy task, generally more economical and feasible way is to use the wall cement wool method, although this method is more old and not very beautiful, But it can play a very effective role in the sound diffusion of the hall.
Moreover, the reasonable arrangement of the audio system, especially the positioning of the speaker must be strictly required. It would be nice to use computer design software provided by some speaker manufacturers for sound field simulation in the design, and if not, it should be adjusted until the live sound field.
Avoidance of sound flutter, focus, and feedback
For the problem of poor sound reinforcement caused by sound flutter, sound focus, and sound feedback, some people blame the whole cause on audio equipment, which is not appropriate, in fact, they should all belong to the category of sound field.
Usually these problems do not occur all the time, so in the general engineering often can not attract enough attention, even if these problems occur, many people do not realize that this is caused by the unreasonable sound field, or just know that the sound field is unreasonable, there is no way to solve it.
Sound chatter, for example, the sound system is generally working normally, but occasionally a rhythmic pulse-like "fluttering" or "buzzing" sound can be heard in the scene, which is usually prone to occur somewhere in the low and mid-frequency bands. In large halls, this sound is separated from the direct sound for a long time, which makes people sound very uncomfortable, which is called tremor.
The reason is: the sound is reflected back and forth between the relatively parallel walls in the hall, and the reflection of the wall is very strong, and the sound energy is difficult to weaken, so it is required to check at any time whether there are two large parallel surfaces with strong reflection in the hall at any time, and whether there are too many glass, stainless steel structures. These things, which seem common to the decoration unit, can cause problems.

The curved surface where sound focus occurs is placed on some large decorative items or hanging curtains, curtains, etc., to reduce the possibility of sound focusing occurring.
The early prevention of acoustic feedback is more difficult, and the frequency of feedback can not be accurately predicted during design, but the prevention of acoustic feedback is more important for practical applications, so it can be used to analyze the sound absorption coefficient at different frequency points when selecting decorative materials in the early stage of design, and refer to the calculation of reverberation time to roughly judge, providing necessary reference for construction and debugging.
Of course, in order to completely solve the above problems, only rely on the later equipment debugging to improve, generally after the completion of the project, use the signal generator and spectrum meter to detect the indigo point of the sound reinforcement area, and use the repeated debugging of the equipment to make up for the lack of sound field.
Calculation of reverberation time
Reverberation time is a quantitative metric that can be controlled in the design. The importance is that, if properly designed, the sound system performs very well, giving the impression that the sound is full and round, without dragging or disturbing. It can be said that if the requirements of the previous sound field design can be better met, and the reverberation time can be well controlled, the acoustic effect can be added a lot. Before calculating, you must first choose a reasonable reverberation time target value, which is generally selected according to the volume and purpose of the hall.
In terms of specific values, most design practitioners prefer to obtain a smaller recommended sound field reverberation time, the reason is: the sound field reverberation time can not be adjusted after a long time, so some people suggest that the hall natural sound is as dry as possible, hoping to add artificial reverberation to the system in debugging and use to meet the requirements of reverberation.
At the same time, in recent years, the increasing update of interior decoration materials, materials with high sound absorption coefficient are widely used, so that the reverberation time of a large number of halls is generally small, it can be seen that the starting point of this design principle and the influence of objective conditions are not doubted, but you know, the reverberation sound in the sound field courtyard refers to the natural reverberation sound produced by the sound source, which is based on the direct sound to show its particularity, is an important feature in the sound field.

And when the system is used, add artificial reverberation, which is equivalent to the direct sound in the signal also into the reverberation, at this time, and then the sound played by the speaker, there is no direct sound that the sound engineer wants you to hear, although different degrees of reverberation are usually added when recording programs, which is equivalent to destroying the program source (sound source), so this method not only disrupts the good foil relationship between the direct sound and the reverberation sound, Moreover, it goes against the purpose of sound field reverberation to make the room have a proper "hall sound". The author believes that this point can be raised for discussion by engineering designers.