Product description:
The acoustic reverberation room is a laboratory that can reflect all sound energy on all boundaries and fully diffuse it so as to form a diffuse field with uniform energy density everywhere and random distribution in each direction of propagation. The reverberation room is also called the audio-visual room. In order to improve the audio-visual evaluation environment, in order to correctly determine the electro-acoustic cycle and audio equipment, it is necessary to construct a room based on the audio-visual acoustic characteristics. The reverberation room is made and decorated with soundproof materials such as soundproof walls, diffusers, and sound-absorbing panels.
The main function:
The function of the acoustic reverberation room is mainly to determine the sound absorption coefficient of materials, the sound absorption in the air, the sound power and frequency spectrum of sound sources and machines, equipment, etc., and to measure the efficiency of certain electro-acoustic devices and equipment and other acoustic performance and effects. Sensitive parts are used for noise fatigue test, etc.
According to the standard:
GB/T20247-2006 Acoustic measurement of sound absorption in a reverberation room;
GB/T 36075.2-2018 Acoustics "Measurement of room acoustics parameters" Part 2: Common room reverberation time
Experiments that can be carried out in the reverberation room:
Simply put, the reverberation room has an echo effect in which sound is emitted and reflected, while the anechoic room has no echo, and the sound is completely absorbed after it is emitted. Therefore, in practice, most reverberation rooms are used for acoustics and acoustic testing, and are mainly used in studios, audio-visual studios, cinemas, high-level conference rooms and other places.
Structural features:
The reverberation time of the reverberation room should be as long as possible to ensure that the sound energy is fully diffused. Therefore, irregular rooms whose surfaces are not parallel to each other are generally built, or the ratio of any two scales of length, width, and height is not equal to or very close to For a rectangular room of a certain integer, the ratio recommended by several International Organizations for Standardization (length: width: height): 1.54:1.28:1; 1.58:1.25:1; 1.69:1.17:1; 2.13:1.17:1; 2.38: 1.62:1; The average sound absorption coefficient of the entire surface of the room should not exceed 0.06. Generally, it can be achieved by brushing enamel, laying tiles or sticking copper foil on the surface of the room. In order to increase the diffusion of sound energy and improve the uniformity of the sound field, a fixed diffuser can be hung in the room and a large rotating or swinging diffuser can be installed. The wall should be thick to avoid resonance of the wall itself and absorb a lot of sound energy. It is also necessary to avoid resonant sound absorption due to the door gap being too large and the sound leakage or not thick. The volume of the reverberation chamber is generally 70~300m, which is determined by the lowest frequency to be tested. The volume of the standard reverberation chamber specified by the International Organization for Standardization is 200m±10%, and the lowest testable frequency is 125Hz (1/1 octave) or 100Hz (1/3 octave), and its reverberation time is generally a few Seconds to tens of seconds.
For the evaluation of the reverberation room, in addition to measuring the reverberation time, the compliance of the diffuse field conditions in the room should also be tested. Generally, more than 6 measuring points in the sound field should be selected. The measuring point interval should be greater than λ/2, and the standard deviation of the measured sound pressure level should be less than ±1dB.