Relevant technical standards involved in sound engineering

Because the sound engineering involves more related technologies, and the quality of the project can be measured by the necessary testing methods, the relevant departments of the state have successively formulated a number of national or ministerial standards.

1 national standard

These standards are developed by the majority of scientific research authors according to the development of professional audio technology and construction technology in China, with reference to relevant foreign regulations. Their formulation and implementation are constantly developed and perfected in practice, which fully reflects China's professional audio. The technical level of the industry, as an engineering and technical salesman engaged in the professional audio industry, should have an in-depth understanding of these standards, and some projects with higher requirements for electroacoustic quality should be strictly implemented according to standards, among which there is a high reference value for engineering construction. : GB3947——Acoustic terminology; GB4959——Measurement method of sound reinforcement characteristics of halls; GYJ25——Acoustic characteristics of Hall sound reinforcement system; SJ2112-82——Preferred electrical matching value of equipment interconnection of hall sound reinforcement system; GB/T14218 -93——Electronic dimming equipment performance parameters and test methods; GB/T15485—the calculation method of speech intelligibility index and so on. Due to space limitations, the specific content of the standard is not excerpted here, but engineering and sales staff should carefully collect this information for reference during design and testing.

2 design principles

A qualified project must be designed in a standardized way. A high-quality project is inseparable from scientific and rigorous design. The scientific design is based on a large number of relevant standards, completes a series of calculations, masters all equipment performance and combines The design of the designer's experience, with scientific design, the construction of the project can be reliable and reliable quality, especially the quality of sound engineering, is a comprehensive technology, and with The development of science and technology, the improvement of equipment grades, and the cost of engineering are also getting higher and higher, so it is necessary to eliminate projects without design, no standards, and no drawings. Since the design of the project is so important, what about the design of the project? This starts with the principle of determining the engineering design, which is the design principle of the important five links involved in the engineering design. The following is a few aspects.

(1) Principles of master planning

The master plan is the first and most important work of a project. It requires the designer to consider it all, and the idea is clear. At this time, the irrationality and incompleteness will affect the quality of the project. The overall plan includes the positioning of the project. The sound of the building, the requirements for architectural decoration, the positioning of the sound and light, as well as the safety and rationality of the project and the impact on the environment.

The positioning of the project should be based on the principle of seeking truth from facts. Do not pursue unrealistic high-end and fancy, nor ignore important functions that affect the quality of the project;

The sound of the hall should follow the sound equipment to show the best results in the corresponding environment. The significance of this work is very significant, and it is also the best to test the level of the designer, with the requirements will be discussed later;

Requirements for building decoration should be conducive to the construction principle of sound and light effects; targeting audio and lighting should give full play to the performance of the device as a starting point to reach the beautiful sound stage, lighting and a good purpose;

The safety and rationality of the project and its impact on the environment should be based on strict compliance with the laws and regulations of the relevant state departments, especially safety and fire prevention, reasonable use of electricity, and avoiding environmental pollution.

(2) The principle of determining the sound of the sound

The sound of sound engineering is mainly the sound of the hall. The reasons for the different levels of equipment are different. Generally, the conditions for sound construction are different. No matter how good the equipment is, once placed in an environment with poor sound conditions, Certainly, good results will not be achieved, and the requirements for building sounds will vary depending on the requirements of the project. At the same time, they will also be affected by the quality and materials of the building decoration. Therefore, we cannot generalize the halls that we generally recognize. It should be reasonable reverberation, good sound diffusivity, no sound focus, no audible vibration noise, no sound shadows, etc. The requirements for sound construction cannot be unilaterally performed by the sound designer, it needs to be clearly used by the user. Under the premise, combined with the strong cooperation of building decoration technicians and decoration materials designers, it is necessary to start the overall planning work of sound engineering as soon as possible, and often maintain close contact with each other to achieve mutual understanding and closeness. Coordination, in which the choice of reverberation time can be determined according to the nature and use of the project, if necessary

(3) Principles for determining sound reinforcement

The so-called sound reinforcement form refers to the use of mono, stereo or add surround sound system for sound reinforcement, usually for the less demanding language sound reinforcement places should use mono first sound reinforcement, not only for saving money, but also In most background music sound reinforcement methods are the most widely used, but it is quite difficult to achieve stereo sound in the entire sound reinforcement area, which requires reasonable configuration of the equipment at the time of design, and the speaker position should consider the electroacoustic me. Finally, it needs to be adjusted according to the specific conditions of the sound field; the surround sound system is derived from the film sound reinforcement system, and its requirements for the environment and equipment are all special. The international and domestic standards are specified, and the film surround sound is strictly speaking. The system is independent of the general sound system, so if you don't know much about the surround sound of the movie, don't add the so-called surround sound system lightly. Back to the unreasonable surround sound configuration can not only form the surround sound, but also destroy Sound field, interfere with stereo playback, the result will be half the effort; but considering the rise of home AV systems, the more

(4) Principles of determining light

Compared with the sound , the professional level of the lighting is higher, so there are not many in the general books and articles. The only technical articles are also more practical and less practical. The reason is the lighting. Classification is like the difference between performance equipment and recording equipment. The purpose is different. The location is different. The design and construction of lighting are completely different. For the performance of stage performance, there is a related specialty in the drama school. The lighting was introduced separately at the Film Academy and the Broadcasting Academy. As for the performance lighting for theatrical performances and entertainment, there are more tricks. If you go to the lighting group of the literary group, they will talk about a lot of topics about lighting. It is required to be cautious in the design of lighting in professional sound engineering, especially when it comes to the stage and special purpose engineering. Designers must study carefully, and if necessary, please consult with professional design units.

(5) Determination principle of positioning

With the determination of the above principles, the positioning of equipment in the project should be considered in the end. The basis of positioning is the overall planning under certain investment. The reference point is the equipment price of the market at that time. Another point that cannot be ignored is the consistency of equipment positioning. Regarding the consistency of equipment positioning, engineers and technicians often encounter it. The equipment positioning is often inconsistent due to cost reasons, equipment performance and improper configuration. The result will be: unstable system operation. Or the level of the system is subject to certain equipment. Therefore, maintaining the consistency of equipment positioning determines the final quality of the project to a certain extent. In addition, because the positioning of the equipment involves the contradiction between cost and funding. Both parties will argue over this issue, so designers should work with the finance staff to carefully calculate the cost, that is, to ensure that the price is dominant and the company's economic interests are guaranteed. In particular, many professional brands of foreign high-quality brands are gradually entering, and the competition of various agents is very fierce. Therefore, in many cases, if the selection is right, the cost can be reduced under the premise of the same positioning and reasonable configuration. satisfaction.

3 overall design

After fully understanding the nature of the project, you should start the overall design of the project. The overall design is the most important basis for engineering construction. The overall design should be carefully examined after detailed investigation of various aspects, and then the designer should come up with a master plan, which will be agreed upon by both parties. After that, the modified scheme is improved in one step, then classified and designed and calculated, and finally the equipment configuration is completed according to the design scheme.

overall plan

The principle of determining the overall plan has been analyzed in the past. In order to carry out the overall plan well, it must be done in a timely manner: comprehensive consideration, no matter how small, that is: to take into account the various factors involved in the project, in the project Before the construction starts, it is necessary to clear the obstacles for the following construction in the preparation work, but it cannot affect the overall planning because of some small considerations. Therefore, the overall planning needs to be carried out by technicians with rich design experience.

(1) Project positioning

Engineering positioning is what users want to know most, and most users need to know what the design has, what level it can achieve, or more specifically whether the project can meet or exceed a project that he is familiar with. Therefore, the designer should let the other party fully understand the design idea and let the other party clearly understand the performance of the device. For example, the project has certain requirements for the performance of the performance. Your design should tell the other party which design configuration is considered for the performance. how the stage lights are arranged in order such as; room for improvement in the design of sound effects and lighting effects have been little likelihood of improvement is still very great, you have to clear each other how your design is adjusted.

(2) The sound of the hall

The vast majority of projects are implemented within the sound of the hall, the hall of the overall quality of performance related to whether the device can effectively play, especially built for sound effects sound hall had a big impact, so no matter what the conditions should be honestly do For this job, the result will be a great benefit. First of all, the structure of the hall should try to avoid generating standing waves. According to the normal frequency formula: the ratio should be an irrational number to make the normal frequency distribution uniform, thus effectively avoiding the generation of standing waves. Some halls are specially designed for sound engineering. Sound technicians can make corresponding requirements as soon as possible. For the halls that are to be transformed, it is necessary to get in touch with the relevant personnel before the start of the transformation, and timely propose the construction requirements for sound field construction. Part of the hall can be effectively avoided to avoid the standing wave, width, height ratio (L, W, H can be interchanged in the same group).

Secondly, in order to ensure better sound reinforcement and lighting projection area, the height of the interior space of the highest hall is guaranteed as much as possible. Some projects do not fully consider the requirements of sound and light when selecting the site, and the hall of several hundred square meters is not in the field. 3m high, it is conceivable that the sound and light effects here will not be too good. In addition, in order to avoid the sound vibration of the sound field, try to make the wall surface slightly parallel, especially the narrow hall should pay attention to the wall treatment. Such as making a handle or decorative surface that is not parallel, etc.; in order to avoid the sound focus affecting the sound gain, try to deal with the curved wall, at least not as a stage. At last. In order to make the operation easier and more convenient, we must pay attention to the setting of the control room. Since many projects do not take into account the wiring of the project, the placement of the equipment, the operator's vision and other factors, the control room is either small or completely isolated from the hall, leaving some regrets for the project, so the following points should be noted:

1, the space of the control room should be as large as possible, the specific size can be determined according to the number of cabinets, the number of staff, generally 7 ~ 10 square meters is more appropriate;

2, the location of the control room should be conducive to laying pipelines, power supply should also be more convenient, especially in some large DISCO halls, the console is set in the high place or the center of the hall, it requires the construction of the decorative part to create a sound engineering construction Contingent conditions;

3, the control room should be able to maintain a good connection with the outside world, which is good for observing the outside world. Some engineering control rooms are completely isolated from the site or only small windows are connected to the site, which makes the operator unable to master. On-site audio and light conditions, many times the sound control by headphones alone, which brings great inconvenience to the work, it is very unreasonable, because the headphone monitor can understand the signal in the device, and the scene will be because of the sound field The excellent, the number of people, and even the changes in the atmosphere require different adjustments to the sound . In particular, the volume needs to be well understood by the operator. If the control room is too isolated from the scene, it is easy for the operator to make mistakes and the volume of the site is small. He didn't know that he didn't think it was enough when the volume was loud. As for whether the control room should be located on the same side of the stage or at the other end of the stage, it is necessary to look at the actual situation. It cannot be generalized. In general, in the place where the stage performance is the main place, the control room can be placed on the same side of the stage so that Keep in touch with the actors; for entertainment or on-site lighting, try to place the control room on the other side of the stage to better observe the atmosphere, needs, and lighting conditions.

(3) Requirements for architectural decoration

For sound engineering, reasonable architectural decoration will bring very favorable conditions to the project. Therefore, the design and coordination of sound engineering must be carried out before the start of architectural decoration. If the overall plan of decoration is confirmed, even the decoration project is about to be completed. The design and construction of the sound engineering will not be able to get strong cooperation, which requires the audio technicians to put forward the requirements of the sound engineering for architectural decoration.

Morality is the color requirement of architectural decoration. Many people do not know much about this. It is very difficult to get their approval. At the same time, it is very likely that there will be conflicts with the architectural decoration department on this issue. Therefore, it must be prudent and reasonable. The requirements, in fact, the color of architectural decoration will affect people's intuitive understanding of sound engineering to a certain extent, the effect will have an impact on the performance of the light, so it should cause enough attention, especially for general versatility, especially because The reason for the hue is that it is too dark when used as a conference or performance. For the performance venue, the decoration of the stage part should be considered under the light; for the entertainment DISCO hall, the light should be referenced on the ceiling and the ground. Design advice, because most computer lights and effect lights are generally reflected in the air and the ground, and the color of the ceiling and the ground is related to whether these beams and patterns can be well set off.

Secondly, the requirements for building decoration ballots, building decoration projects will make their own choices in terms of materials due to structural reasons for construction reasons, but for the requirements of sound engineering, certain ballots often bring negative The impact, so should also put forward relevant requirements, it is essential that the material that has a greater impact on the sound field of the hall must be guaranteed, for example, the data difference caused by the perforation rate of the sound-absorbing perforated plate is very large. The hollow building materials should be used as little as possible; the materials with higher reflectivity should not be used on the wall as much as possible.

Furthermore, it is the requirement of architectural decoration technology. It should be said that the general architectural decoration process will not affect the sound engineering, but if some small links are not handled properly, it will bring hidden dangers to the sound field, for the requirements of sound engineering. It should be resolutely avoided to have large hollow or poorly supported cavity structures in the sound reinforcement area, otherwise resonance and noise are easily generated, and the source of these noises and the frequency of resonance are hard to find, even after discovery. It is difficult to solve, so it should be paid special attention. For example, the keel in the wooden wall skirt must be tight and dense, and the inside of the dance should not be too big; the floor or dance floor must have more floor support points, and the floor space of the dance floor should not be too high. it should also be noted that the installation of the glass ceiling and must consider the vibration, or sound even at high volume work, these decorative materials generated vibration will make people very uncomfortable, especially in the bass region is more obvious, so generally do not use large For the glass window of the area, do not install the plaster ceiling directly in the aluminum alloy tank. You should add a rubber mat and so on.

(4) Target positioning of audio and light

Many of the effects, features, and styles of sound engineering are subjective, especially for users who are not familiar with audio and lighting. Their final practical effect on the project can only be guessed, and they want to compare the objectives of the project. Difficulties, however, the project's target orientation is very important for the project's style and engineering investment, so the two parties need to seriously negotiate.

The style of the project should be positioned with full respect for the user's opinions. With an honest attitude, try to let the other party understand the functions and overall style of the system after the completion of the project. Do not hope that the user can raise the cost to reach a so-called " "High-end requirements" to add some unnecessary functions, we should implement a practical and applicable plan for the user in a pragmatic attitude, so that we can get the good trust of the other party, so that the project can be satisfied by the user, if it is used blindly As high-end equipment, it is not only difficult to form a unique style, but also because the equipment is too complicated, resulting in poor use, and the low cost does not necessarily mean that the quality of the project is not high, this should clearly know the user, Under the premise of guaranteeing certain styles, we should also reasonably grasp the proportion of sound and lighting in engineering investment. The target positioning of the project often needs to be achieved through this ratio. What should be explained about the ratio is that the general acoustic lighting project first It is more difficult to raise the grade on the sound than on the light.

The relationship between these two aspects is specifically applied to the actual project: for projects with lower cost or higher requirements for sound, first of all, we should consider working on the sound , and then use the appropriate funds for the lighting; The higher the grade or the formal performance of the project, after ensuring that the sound has a certain level, the primary consideration is the upgrade of the light, because the change of the lighting grade will be very prominent in the eyes of ordinary people, and the sound grade should be improved. It tends to increase the investment by multiple times, and the effect is not necessarily recognized by the general public. For example, the multi-purpose hall for general use, the proportion of equipment investment in the entertainment center can be used for audio : lighting is 2.5:1.5, 2.5:1, 3: 1 even 4:1 and so on; and as a business audio : lighting is 1:1, 1:1.5, 1:2, 1:3 or even higher, of course, what proportion should be used or should be based on the function of the project According to the experience of the design salesperson.

(5) Safety and rationality of the project and its impact on the environment

Because it is a master plan, it is necessary to consider all aspects of the project, including the safety of the project and the impact on the environment. The safety of the project is often not noticed, only when it happens always or when trouble occurs. It is important for sound engineering. Safety involves both design and construction. The safety of design is: whether the power distribution is reasonable, whether the power is safe, whether the equipment connection is scientific, whether the load is guaranteed, whether the wiring is correct, etc. Etc. The safety of the construction is: whether the equipment is installed firmly, whether the debugging is going to cause damage to the equipment, the project acceptance is unqualified, and the safety will endanger the personal safety. Therefore, the designer must not neglect the importance of safety. In terms of impact, it is mainly the interference of noise to surrounding residents and units. As users, they have considered this problem before the project is completed. The design salesperson is a technician with practical experience and also knows about the corresponding project. If the situation is explained to the other party before the start of the project or during the construction

Sound field design

To give a similar example: everyone knows the relationship between the speaker unit and the cabinet in the speaker. Many people have come back to the famous foreign speaker unit including the crossover, but they can't make a good speaker anyway. the main reason is the acoustic structure of the housing problem is not resolved, as important cabinet, designed like a good sound field as more important than the production of the speaker cabinet design design sound field like sound engineering design than the production of speakers, a good The sound field will fully play the advantages of audio equipment, which makes people sound very comfortable, and an unreasonable sound field will not only give people a wonderful sound experience, but also reduce the performance level of the equipment. Of course, due to architectural decoration The level and the user's understanding of the degree of sound engineering, many projects are very late to contact the sound construction unit, so that the design of the sound field can not be completed, and the sound field design must rely on the architectural decoration to achieve, so a large number of sound engineering is in

A basic sound field design includes sound insulation processing, site noise reduction, building structure requirements, sound uniformity to achieve acoustic tremor, focus, feedback and other issues to avoid, indoor calculations, etc., the following classification for analysis.

(1) Sound insulation treatment

In order to create a quiet sound field and avoid affecting the units and residents in the surrounding environment, at the beginning of the sound field design, the sound insulation should be considered first to provide a good innate condition for the sound field. The sound insulation involves the construction. Sound insulation with the outside world, sound insulation of each room in the building; sound insulation parts include: sound insulation of the partition wall, sound insulation of the doors and windows, and sound insulation of the ceiling of the room connected to the top.

For the sound insulation with the outside world, the general building structure can achieve the basic sound insulation requirements, but if the architectural design does not consider the need of sound engineering at all, it is necessary to conduct an investigation of the sound insulation, and if necessary, should design the building. The unit conducts consultations and knows the local noise restrictions from the public security organs. Usually do not use the height of the floor as sound insulation for the sound insulation between the rooms. If the wall is too thin, it will bring some difficulty to the project. This time, in consultation with the decoration unit, add a layer to the wall during decoration. Intermittent to solve the high and medium frequency sound insulation.

It is more difficult to completely solve the sound insulation of the low frequency band, because there is no other more effective way to increase the weight of the sound insulation. Doors and windows are the weak link of the sound insulation treatment. For their sound insulation, it can be recommended to the decoration unit. Improve the quality of the production of doors and windows, if necessary, the use of leather doors and double-glazed windows, or the addition of isolation channels outside the door and the thick double-layer curtains hanging on the windows, etc., is also the key to the ceiling of the ceiling room. Especially in some large-scale entertainment venues built, the sound of the hall has a great influence on the surrounding rooms. Some of the disturbances are from the top of the ceiling. This part of the sound insulation scheme cannot be raised too late, otherwise it is difficult to implement, so it is difficult to implement. The sound designer is required to ask the decoration unit as soon as possible to coordinate a feasible solution, such as: covering the ceiling with a layer of fire-resistant sound-absorbing cotton or adding a layer of ceiling to the ceiling of the ceiling, etc. In short, the sound insulation of the project The handling is of great significance, both to improve the quality of the project and to facilitate the normal use of the user, and at the same time should pay attention to careful examination

(2) Reduction of on-site noise

For the background noise of the scene, many people do not pay attention to it, but in the relevant national standards, they all put forward corresponding requirements, such as: the first-level karaoke should be less than 35dB, the first-level disco should be less than 40dB, the reason is: the increase of background noise The large corresponding reduction of the signal-to-noise ratio of the sound reinforcement system affects the quality of the project. To effectively solve this problem, the above-mentioned sound insulation is limited, for example, whether the air-conditioning noise of the central air conditioner allows the installation unit to help solve the problem; The noise, size, installation location, etc.

(3) The situation of the building structure

It should be said that the general sound is not capable of letting the building structure completely designed according to its own intentions. However, for the part where the engineering quality requirements are strict and the construction engineering is processed on the reconstructed structure, it is necessary for the sound designer to make corresponding requirements as much as possible. The optimum proportion of the length, width and height of the structural part, the shape of the wall, and the position setting of the control room have already been mentioned in the overall planning of the front. Here, some architectural partial structures related to the engineering installation are mainly mentioned here. In the first case, the building unit must first obtain the recognition of the load-bearing capacity of the wall or roof of the sound engineering that needs to be hoisted equipment. Especially when the weight of the light shed is large, the safety of hoisting is more important. Secondly, it needs to be The structure of the room in the building, the location of the pre-buried pipeline, and the exit have a more detailed understanding to facilitate the possible insertion of the pipe and wiring, and then to understand the weak links of the internal structure of the building, to find out what landlord can change, what No place.

(4) 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, right? No, not only important, but also very important. For example, if you go to an entertainment hall, you will find that the sounds in different places are different. Some places are very beautiful. Some places are like shortcomings. The sound is erratic. Another example: the front stage area is very loud, while the audience behind it says that the sound is small (of course, some entertainment halls are designed to make the back area easy for the audience). These phenomena are all caused by poor uniformity. In the standard, it is based on the concept of sound field inhomogeneity. It is generally required that the field pressure level test value deviation is less than 2dB at each point. How to achieve a uniform sound field?

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 walls should avoid trapped arcs, especially the wall on the side of the stage should not have a large structure; Large acoustic shadow areas appear in the interior, but since a large number of changes cannot be made to meet these requirements after the completion of the construction of the building structure, it is necessary to use the experience in the sound engineering to skillfully arrange the sound reinforcement area and avoid the comparison. Large defect structures that minimize their impact;

Secondly, it can provide some simple solutions to improve the sound diffusion effect to the decoration unit in a timely and effective manner. For example, all concert halls have good sound diffusion effects because a large number of sound diffusers of various shapes are used inside, and These structures can be completed by some simple decoration methods, so as long as the method is right, the better results can be achieved. Of course, it is not easy to properly and properly design the shape, position and quantity of the diffuser. The feasible method is to use the wall cement to pull the hair. Although this method is relatively old and not very beautiful, it can play a very effective role in the sound diffusion of the hall. Moreover, the sound system is arranged reasonably. It is necessary to strictly set the position of the speaker. If you can use the computer design software provided by some speaker manufacturers to simulate the sound field in the design, it is better. If not, it should be adjusted in practice until the sound field is the best.

(5) Avoidance of acoustic vibration, focus, and feedback

For sound vibration, acoustic focusing, acoustic feedback caused problems of poor sound effects, some people can only say good general sound effects, all owned by the reason for the device, this is not appropriate, in fact, they should belong to the sound field Category, usually these problems do not happen from time to time, so in 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 that is known as the sound field The hospital is unreasonable and there is no way to solve it. For example, the sound system work is generally normal, but occasionally a rhythmic pulse-like sound or "squeaky" sound can be heard on the spot. Usually it is most likely to occur in a certain place in the middle and low frequency bands. When the hall is large, the sound is separated from the direct sound for a long time, which makes people sound very uncomfortable. This is a kind of tremor.

The reason is that the sound is reflected back and forth between the parallel walls in the hall, and the reflection of the wall is very strong, and the sound energy is hard to be weakened. Therefore, it is required to check whether there are two reflective objects in the hall at any time during the decoration. Large-area parallel faces, there are not too many glass, stainless steel structure, because these things that seem normal in the decoration unit, may cause problems; the arc-shaped surface of the sound focus occurs some large decoration Items or hanging curtains, curtains, etc., to reduce the possibility of sound focusing; pre-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. Therefore, it is possible to analyze the sound absorption coefficient at different frequency points when designing the decorative materials in the early stage of the design, and refer to the calculation of the reverberation time to make a rough judgment for the construction and commissioning. Of course, it is necessary to thoroughly solve the above. Many aspects of the problem, relying on the later equipment debugging to improve, generally after the completion of the project, using the signal generator and spectrum analyzer

(6) Calculation of reverberation time

For the sound field design, the average person can understand intuitively, and the more contact is the reverberation time, because it is the most controllable quantitative indicator in the design. The importance of reasonable reverberation time is reflected in the design. The sound field will make the sound system perform very well, giving the impression that the sound is full and round, not dragging, and not disturbing. It can be said that if the requirements of the sound field design in the front can be satisfactorily satisfied, the reverberation time can be controlled. is good, you can make the sound effects considerably, before calculation must first select a reasonable reverberation time target, for selecting the value of the volume and generally use the hall.

On the specific value, most designers prefer to make the recommended sound field reverberation time smaller. The reason is: the sound field reverberation time can not be adjusted after a long time, so it is suggested that the hall should be more natural. The better, the better, in the debugging and use, the artificial reverberation is added to the system to achieve the reverberation requirements. At the same time, the interior decoration materials are increasingly updated, and the materials with high sound absorption coefficient are widely used, which makes the reverberation time of a large number of halls. Generally speaking, it can be seen that the starting point of this design principle and the influence of objective conditions are not doubtful, but it should be known that the reverberation sound in the sound field yard refers to the natural reverberation sound produced by the sound source. It is an important characteristic in the sound field by adding direct sound to the sound field. When the system is used, artificial reverberation is added, which is equivalent to adding the direct sound in the signal to the reverberation, and then playing it out by the speaker. In the voice, there is no direct sound from the sound engineer who wants you to hear the period, although recording the program usually adds different levels of reverberation, which is equivalent to destroying the source of the program (sound source) Therefore, this method not only disturbs the good relationship between the direct sound and the reverberant sound, but also violates the sound field reverberation in order to make the room have the proper "canton" purpose. This point I think can be put forward for engineering. Design sales staff to discuss.

The brief reverberation time is calculated as follows:

General engineering can be carefully calculated at home at 500 Hz or kHz. The sound absorption coefficient of various materials should be strictly in accordance with the data provided in the product parameters or the building materials manual. Otherwise, the calculation results may be larger and larger, of course, with the recommended values. Based on the near calculation results, the designer does not need to ask the decoration unit to improve too much, because the reverberation time requirement is not a specific absolute value, as long as the disparity is not too large, the calculation should also consider the audience. The effect on reverberation time.

(7) At the end of the sound field design, the calculation of sound pressure level should also be considered.

其目的不光是为了给使用者提供可行的工程电声参数,以利于他们安全正确地使用设备,创造一个健康卫生的听音环境,同时还中为了给音响工程中的电气设计提供依据,为设备的选型提供参考。

在进行声压级计算前,必须选择一个相应合适的环境其准声压级,而基准声压级的选择就必须了解正常人耳的等响曲线,即弗莱切——芒森曲线。

该曲线反映了人耳对不同频率、不同声压的听感响度反应,曲线上的数字表示相应频率和声压下的响度值,单位是:Phono,人耳对相同声压不同频率的声音的反应是不一样的,同样声压级的低频声音在人耳里产生的响度感觉要低于同声压级的高频声音;要想各频段的声音在人耳里产生的响度基本一致,不出现某些频段听感的不足,就必须使声压达到足够的声压级,这就是声压计算时基准声压选取的依据。

用以语言扩声的工程,由于语言信号主要集中在中频段,这里的等响应曲线度相关较小所以基准声压级可以取70~80dB;用于一般音乐重放的音响工程,这个基准声压可以取85~90dB作为计算的依据;同时为系统的扩声留下12~18dB的峰值的余量及1~3dB的环境噪音余量,那么在平均的听音距离上,设计的额定扩声声压级应该是:P额=(85~90)dB+(1~3)dB然后需要根据厅堂的实际扩声范围确定平均的听音距离L,额定的声压级就应该是在此位置的实际声压级,然后依此可以通过计算得出音箱的1m位置声压级P:

根据前面提及的:距离变化一倍,声压相应变化6dB的关系,则音箱在1m处需要提供的声压级为:P=P额+6LogL至此声扬的设计便基本结束,其后的工作就是与建筑装饰单位密切配合将设计要求付诸实际。

4 音响工程施工的步骤

(1)首先要进行管线和挂接件的预埋

管线和挂接件的预埋一般需要在工程项目确定后就应该马上开始,因为通常来讲,预埋的管线主要都在没有搭建的舞台里、或没有装饰的地面豚墙面里,如果不及时进行预埋,就很容易影响装饰工程的进度,同时必须引起重视的是预埋管线的出口一定要协同装饰部门处理,否则有可能由于处理不当而影响装饰的美观;挂接件的预埋位置和吊装强度一定要得到建筑技术人员确认,否则安全性无法得到保证,通常,需要埋设在水泥结构里的管线要选择质量好些的钢管,口径按照所穿的线缆多少来决定;穿过顶棚、装饰墙体的管线,一般选用铁制或防火PVC线槽,主要是穿线施工方便,容纳的线缆量较大,又能防火;对于埋设距离较长的管线,一定要在一定的距离开设检修口,最后必须注意的是,预埋管线的工作几乎是无法更改的,一旦决定了在什么地方,埋多少,怎么埋,而且预埋完工后,要想更改就不太可能了,所以预埋前一定要认真地分析设计,明确设备的数量、位置、供电情况及控制方式,在此基础上提出准确的管线数量、口径和走向。 注:此项在项目启动时乃重中之重!必须要认真按标准执行!才能保证工程质量。遂项目启动时就应与甲方以及装修施工方进行协商调解。

(2)其次要进行各种棚,架的焊接和安装

这项工作尽量与装饰工程交叉进行,因为在施工中难免开启一些孔洞以及对已有的装饰物产生破坏,这些都需要装饰施工方协助完成,理论上来说,在焊接的过程中,要让具有焊接资格的工人操作,这样做除了方式安全的要求外,主要是焊接质量直接关系到棚架的吊装强度,不能马虎,同时,因为焊接施工通常都是与装饰工程同时进行的,现场会有一些易燃物,所以施工中一定要注意防火,待焊接牢固,油漆完成后,就应该开始这些棚安装了,安装的安全性同样非常重要,必须有建筑技术人员比较充足的时候才能开始吊装;最后就是,所有的安装件都必须增设可靠的保护措施,这样的安装才有安全的保证。

(3)再下面就要进行各种线缆的铺设

这项工作虽然比较简单,但是也应该认真进行,特别是穿管这一项,容不得一点马虎,铺设线缆要掌握合理的方法,例如穿管时钢丝与要穿的线缆应该捆扎牢固,扎头要得减小阻力,必要时涂抹少量的润滑油;其次线缆损坏或错乱的麻烦;再者就是要在线缆铺设时认真对线缆进行检查,象外皮是否破裂,屏蔽层是否损坏以及芯线是否断裂等等;最后,一定要在铺设的线缆上做好明显的标记,以备安装设备和日后检修时使用。
注:此项在施工过程中乃重中之重,这关系到施工结束后设备运行以及音响音效!

(4)再后面应该进行各种设备的安装

设备的安装必须在装饰完工、线缆铺设正确后进行,因为音响灯光的设备不仅价格较贵,而且许多设备需要避免尘土的沾染,装饰工程凌乱的现场是不适合安装设备的,设备的安装首先应该注意开箱时要仔细检查,因为许多国外设备的包装非常规范,有一些重要的备件或说明书可能单独隔离在包装盒的底层,很容易在拆箱时随包装盒一起扔掉;其次设备安装前应该认真阅读产品说明书,以掌握正确的安装方法、步骤。例如;许多电脑灯的灯泡和镀膜玻璃都要求佩带棉线手套安装,不允许直接用手去接触;最后就是设备安装要牢固,保护措要完备,特别是灯光设备,位置高、重量大而且以常运动,一般又在舞台或舞池的上方,所以必须绝对确保安全。

(5)控制线路和信号线路的连接

这是一项需要细致认真和技术性的工作,所以应该由技术过硬责任心强的人员进行,在线路的连接时,首先要求方式必须确保在无电状态下进行,因为音响灯光设备的电源供应要求不尽相同,如果在安装时就提供电源,不仅安全性差,而且很容易损坏设备;其次,要求施工符合电器安装规范,因为电器安装规范是检验方式是否合理的标准,所以按照规范施工与否,达到期的工程质量是完全不同的,许多按照规范施工的正规的工程内行一看就知道活儿干得“漂亮”;再者,要求各种插接件,大型工程中需用要的各种二芯、三芯、莲花接头、卡侬插头、多芯插头的数量非党大,经常需要几个人同时制作很长时间才能完成,如果在焊接前不了解正确的连接方法和焊接方法,可想而知返起工来会有多么麻烦,所以一定要弄清楚,例如:欧洲的一些音响产品的卡侬脚和一般通用的编号不一样,千万不能焊错;一些灯光的控制线要求屏蔽较高,如果焊接不合理,就有可能使灯光产生误动作;最后要求线路中所有的火线,零线,地线及屏蔽线的连接必须准确无误,在电源供应方面,要注意的是: 音响和灯光的某些设备使用的电源以常会引起误会,例如:有些设备使用110V的交流电,而随机的变压器是单独插接的,如果连接线路时将它遗忘,而直接将设备的电源插头插在于220V的电源上,后果就可想而知了;又比如:一些同边设备使用的是低压交流电,有的又使用低压直流电,它们的插头外形很相似,如果不注意的话,供上电后轻者导致声音反相低消,声压降低,音质变差的后果,同时也容易导致设备外壳带电,留下安全的隐患;从屏蔽来讲,系统网络抗干扰的能力,主要决定于系统屏蔽是否正确及屏蔽是否不工作,重者就会损坏设备,而供电线路相位的错误则可能会影响到音箱的相位,从而否正确及屏蔽质量的高低,常常在一些工程中发现:要么没有进行屏蔽,要么屏蔽层形成闭环回路;要么就是屏蔽线连接错误没有形成屏蔽网络抵抗不了干扰,甚至有些工程的施工人员将信号地和电源的零、地、屏蔽线和信号线这几个要领混淆,胡乱连接,不光抗不了干扰,还会带来大量的干扰,所以一定要先实实在在地把这些概念理解清楚。

(6)对安装、供电线路、连接情况的检查

因为音响工程的整个系统涉及的连接点和插接件比较多,在安装时也有可能因为个别的原因发生错误,所以,细致的检查是有必要的,一般的检查包括设备安装安全性,供电线路是否合理,各插接件的连接是否正确等,另外还有一个重要的检查项目就是:仔细检查每一件设备的状态设置是否满足设计要求,这点绝对不能忘记,否则极易造成设备损坏,这些状态包括;功放在桥接要求时,桥接开关是否置位;各设备的电源选择开关是否合适;灯光设备是声控还是电控;电脑灯的地址码是否设置正确;投影机的输入方式设置等等。

(7)准备进行设备的调试

对于设备的调试,因为各个工程的情况不同,很难统一一个通用的方法,需要单独分类进行讨论。

Wireless Earphones

Phone Wireless Earphones,Sports Bluetooth Earphone,Best Cheap Wireless Earbuds,Wireless Earbuds For Android

Dongguang Vowsound Electronics Co., Ltd. , https://www.vowsound.com

Posted on