We can consider several aspects such as the use requirements of the anechoic chamber, the size of the product under test, acoustic requirements, cut-off frequency, and supporting test equipment.
The first is the size and volume of the product being tested. Generally, the internal space of the anechoic chamber is at least 200 times the volume of the product being tested. Sufficient space needs to be reserved in conjunction with the supporting testing equipment that the product needs to use. space.
In addition to product volume, acoustic requirements also influence the size of the space. The higher the insulation requirements, the thicker the wall thickness, and the available internal space will be reduced. We have also talked about this topic in the explanation of the sound insulation requirements of the anechoic chamber. Trying to choose a relatively quiet environment can also effectively reduce the construction cost of the anechoic chamber.
In addition, the cut-off frequency of the anechoic chamber is closely related to the space size of the anechoic chamber. The cut-off frequency is determined by the length of the sound-absorbing wedge installed inside the anechoic chamber. The lower the cutoff frequency, the longer the sound-absorbing spike, and the internal space becomes limited.

After determining the above points, it is necessary to accurately design the internal space in conjunction with international standards ISO3745 and GB6882 "Acoustics: Determination of sound power of noise sources: Anechoic chamber and semi-anechoic chamber precision method" to ensure the rationality of the overall layout.