MDF milled with slots & holes---it is used to absorb and shrink the echo, when its back is covered with thin cloth.
MDF milled with slots & holes --- It is used to absorb and shrink the echo, when its back is covered with thin cloth: this is what we called Acoustic-absorbable boards
Acoustic - absorbable boards: is usually used together with the thin cloth: because the cloth is very helpful to absord the noise.
Size is customized by customers.
In another word: size is customization.
The following sizes are very common:
1220 x 2440 x 15mm
1220 x 2440 x 16mm
1220 x 2440 x 17mm
1220 x 2440 x 18mm
acoustic - absorbable MDF boards. MDF milled with holes & slots.