1. Design basis
GB50371-2006 "Specifications for design of hall sound reinforcement systems"
GB / T14197-93 "Preferred electrical connection value for sound system equipment interconnection"
GB 4959-1995 "Measurement method of hall sound reinforcement characteristics"
JGJ / T16-92 "Code for Electrical Design of Civil Buildings"
GB / T50314-2000 "Intelligent Building Design Standard"
GB50303-2002 "Code for Construction and Acceptance of Electrical Installation Engineering"
JGJ67—2001 "Code for Design of Halls"
GYJ45—92 "Studio Lighting Design Standards of the Ministry of Radio, Film and Television"
GBJ133-90 "Lighting Design Standards for Civil Buildings"
GBJ45-82 "Code for Fire Protection Design of High-rise Civil Buildings"
Tender documents and site survey data
Multifunctional Conference Hall Lighting and Light Pollution Limitation Standard (WH0201-94)
Acoustic characteristics and measurement methods of multifunctional conference hall sound reinforcement system (WH01-93)
National Tourism Administration, "Star Rating Standards for Foreign-related Hotels of the People's Republic of China".
GB / T50314-2000 "Intelligent Building Design Standard".
Technical Specifications of Digital Stereo Cinemas by the State Administration of Radio, Film and Television.
JGJ / T131-2000 "Acoustic Design and Measurement Method of Gymnasium".
JGJ57-2000 "Code for Design of Theater Architecture".
WH0201-94 "Limited Standards for Lighting and Light Pollution of Multifunctional Conference Halls".
GYJ45-92 "Design Specification for Lighting System of TV Studio".
Specifications and standards of other related industries
2. Design goals and design requirements
(1) The system is advanced
Adopt advanced networked intelligent centralized control system to make multi-functional conference hall and each small conference hall process control operation easy.
Use advanced audio network system to enhance the transmission of audio signals.
Adopt the combination of audio and video technology to make the multi-functional conference hall sound.
Adopt advanced digital audio and video equipment and digital intelligent control system, so that the entire audio and video system not only has extremely high performance indicators, but also can achieve perfect sound reinforcement and film and television playback effects;
Using digital audio processing;
(2) The system is practical
It can meet the requirements of multiple functions such as group gatherings, small and medium performances, personal lectures, academic exchanges, international conferences, press releases, film and television exhibitions and broadcasts;
Meeting requirements at all levels, including meeting recording, music playback, multimedia information display, etc.
(3) The system is scientific
The audio system has the uniform sound field, the language is clear, natural and friendly when expressing language;
The audio system has the characteristics of fullness of sound, accurate positioning, authenticity, and large dynamic range when performing music;
The video system has the characteristics of high brightness, high resolution, delicate images, and true color reproduction;
It has various modes of performing arts performance, static language conference, etc .; the system configuration is reasonable, and the cost performance is high;
2.1 Thinking Mode
The multi-functional conference hall is a high-level comprehensive cultural product. It is a layered system. Each subsystem is composed of elements. They cross into a network, that is, the connection relationship between the elements and subsystems. The structure and the use of the techniques and techniques of the interior design of architectural art to optimize and stabilize it to produce the overall effect of the system. Sound reinforcement systems, building acoustics, lighting systems, and indoor technologies are all components and subsystems of multifunctional conference halls as system engineering. They intersect and intertwin with each other on different levels, each with its own characteristics and contradictions. Therefore, the elements and subsystems must be carefully analyzed and carefully considered to unlock the nodes of their cross-networks, unify the contradictions, achieve the overall effect, and meet the requirements of various regulations. The sound construction design should provide a good sound field in order to give full play to the performance of the sound reinforcement system and its equipment, and provide the methods and layout of sound absorbing materials and components, as well as the prototype of space creation for interior design; also provide good lighting for the lighting system Conditions and play its artistic effect are the basis of the artistic image of the multifunctional conference hall. Similarly, the interior design can provide a suitable place for the speakers and a working place for tuning, and it is also the organizer who unifies various technologies to create a beautiful environment for viewing and listening. However, in practice, they are often independent, independent of each other, and designed independently; the sound reinforcement system designer believes that as long as there is good equipment and system design, there will be good sound reinforcement effects; the sound reinforcement designer only considers how to ensure that the mixed In response to the requirements of time, provide the design of acoustic materials and components; interior designers believe that scientific and technical personnel do not understand art, create behind closed doors, and finally provide a space that they consider beautiful to the scientific and technical personnel, and let them place various equipment and perform in this space. Processing; accordingly, scientific and technological personnel also confessed that they did not understand the art of architecture and ignored them. As everyone knows, the optimization of their own systems does not equal the overall optimization, but often has a negative effect on the contrary. Therefore, various designers of multi-functional conference halls should recognize that multi-functional conference halls are a systematic project. Sound reinforcement systems, building acoustics, lighting systems, interior design, etc., are a subsystem in the system. As a sound reinforcement system designer, the related technology and art should be regarded as a body of knowledge, and it should also be a way of thinking, so as to explore the various intertwined creations of technology and art at a higher level. It is both scientific and The overall effect of art can get good sound reinforcement effects.
In addition to the decoration of the multifunctional conference hall, in order to obtain beautiful visual effects to meet the standard requirements. The reverberation time is a function of volume and can generally be taken about 1 second. Most multi-functional conference halls now use a large number of carpets, or use decorative cloth as a surface, and the interior is placed with plastic or ultra-fine glass wool, so-called "soft bag" processing. This approach will absorb too much sound in the high frequency range and make the reverberation time in the middle and high frequencies short, so the sound in the hall is not bright enough, the definition is poor, it is not gorgeous, and there is no color. There are also a large number of practices that use external plywood or plywood cladding, which is generally consolidated with small nails; some are also covered with a "soft bag" outside, which makes large amounts of low-frequency sound in the hall absorbed. Make the sound in the hall hard, inelastic and unbalanced. Because there is no strict acoustic design, the sound-absorbing materials and components in the hall are single, which results in excessive absorption and distortion of sound at a certain frequency. This makes it difficult to adjust even when using a room equalizer, and it often occurs during the adjustment process. The phenomenon of not being able to continue, causing the sound of the frequency at this point to "taste", and at the same time the transmission frequency effect is poor, the layering is poor, and the sound is not soft.
2.3 Vibration and Noise Reduction
Speakers are set up in the multifunctional conference hall. Both the combined speaker and the woofer must be placed on the structural floor or on a solid support (the woofer should be placed on the floor). The suspension support and fulcrum of the hanging speaker should be firm and not Vibration, otherwise, the sound quality will be deteriorated. Wood decoration methods often cause noise due to inadequate attention during construction and nails. The lighting hangers can also generate low frequency resonance of 40 ~ 80 Hz if not considered carefully. When this kind of vibration noise is adjusted in the room equalizer, the artifact of peak appears in the frequency spectrum. The sound is diminished and the peaks disappear; but it is not linear, so it is difficult to debug. There should be no interference between the KTV rooms and the hall. The total sound insulation capacity of the top grille and the partition wall is about 60dB. 24 brick walls or double-layer 100mm aerated concrete blocks can be used; double-layer plasterboard (2 * 12mm) Double-row keel, hollow 50mm filled rock wool, but not acoustic bridge; all partition walls should be connected to the floor without gaps; most of the current multi-function conference halls have poor sound insulation, mostly due to The partition wall is not connected to the floor, and a ceiling is considered sufficient.
2.4 Control room
The control room is a sound, video and lighting control center for multi-functional conference rooms and private rooms. Due to the increasing complexity and quantity of various equipment, the number of operators has also increased, so the area of the control room should not be less than 20 square meters, and its position should be directly in front of the ballroom. The operator can directly see and hear through the observation window. Ballroom and dance floor performances.
2.5 Acoustic system
The acoustic system of the multifunctional conference hall is composed of the sound field of the microphone (natural sound source) and the sound reinforcement field of the speaker and the sound reinforcement equipment. The quality of the sound reinforcement field is directly related to the quality of the sound frequency characteristics heard, the uniformity of the sound field distribution, and the quality of various acoustic characteristics such as acoustic interference; the maximum impact of the sound field will cause acoustic feedback (howling) ), Seriously reducing the gain of sound transmission; and these two sound fields are formed by architectural acoustics and decoration engineering, which is determined by the interior design, so the interior design of the multifunctional conference hall must fully express its speciality and function. Good and sound architectural acoustics design is the basic connotation of the interior design of a multifunctional conference hall, and it is also the basic guarantee for a sound multifunctional conference hall sound system. Therefore, the design and construction of multifunctional conference halls (including indoor sound construction and decoration, sound reinforcement systems and lighting systems) should not be handed over to some units or individuals without technical strength and scientific means for design and construction.
3. Composition of sound reinforcement equipment
1: Microphones High-end dynamic microphones can be used for performance, and mid-range or low-grade can be used for karaoke. Band or violin, piano or snare drum instruments can use condenser microphones. In order to reduce the trouble caused by the cable, a wireless microphone can be used. It is a dynamic microphone with a radiator, and most of the pocket microphones are an electret microphone with a radiator. Its equipment parameters are slightly lower than those of a wired fax machine of the same grade.
2: The main function of the mixer is to bring various sound sources (microphone, CD player, LD recorder, etc.), various electroacoustic instruments (electronic keyboard, synthesizer, electric guitar, bass guitar, etc.), various peripherals The audio signals of the equipment are mixed and processed as required; certain sound signals are modified and compensated; the acoustic signals are divided into multiple groups and output as required. General multifunctional conference halls can use 8 ~ 16 mixers, and those with bands can choose more channels. The equipment parameters and debugging of the mixer are directly related to the sound quality and system noise.
3: The equalizer is used to correct the defects in the frequency transmission characteristics caused by the uneven resonance characteristics of the room itself and the frequency distortion generated by the sound reinforcement equipment (mainly speakers, microphones, etc.), modify the tone of musical instruments and actors, and improve the performance of art performance. The analog equalizer is made up of analog circuits (amplifiers), most of which are graphical and mostly used as room compensation. Generally only one-time adjustment is required. The digital equalizer adopts computer technology, which can predict and store multiple equalization curves for dynamic and dynamic display of the spectrum. It is mostly used for performance groups that modify the tone color or mobile venues, so it is not used in multifunctional conference halls.
4: Compression / limiter jujube should be used in larger and important protection professional speakers, especially when performing in multi-functional conference halls, so that the system is not overloaded and does not produce excessive distortion.
5: Effects can make up for the lack of natural reverberation in the room, modify the tone and create special effects. The multi-function effector can store a large number of sound processing programs, and perform comprehensive processing on sound signals such as delay, reverb, echo, chorus, re-sing, excitation, equalization, left and right channel redistribution. Reverbs and delays are also effects.
6: Sound exciter It is a sound processing device that generates higher harmonics based on the fundamental frequency of the fundamental tone. It can greatly improve the penetration of the sound in the place where the human voice is chaotic. It can increase the effect when the singer sings or plays the audio tape. It can be used without playing CDs. It is prohibited in serious music places.
7: Electronic frequency divider When the sound reinforcement system has high requirements, the full frequency speaker box (combined speaker box) is generally not used, but the electronic frequency divider is used to divide the audio signal into high, medium, and Lower three power amplifiers, and then drive high, middle, and low speaker boxes to sound (sometimes divided into high [medium] and low two bands).
8: Power amplifier. It is to amplify the weak electric signal by voltage and current (power) to directly drive the speaker. Because it is a high-power output device, the load is mainly a speaker with inductance. Improper use is prone to failure. In order to ensure that I believe that the sound reinforcement is the same, the main power amplifier is best to choose the same brand, it should not be close to the recording base to avoid electromagnetic interference.
9: The speaker is the last important link of the sound reinforcement equipment. It restores the electric power signal to an acoustic signal, so it is also a key link. The combination of the second and third frequency of the full frequency band (from bass to treble) used in the multifunctional conference hall. Speaker box. When the impedance is the same, it is advisable to select 1.5 ~ 2 times the rated power of the speaker. The main speaker box should also use the same brand to avoid sound and image confusion.