High-amplitude audio signals from the center or any sound source to certain decibel values These modules are manufactured as flush-mounted or surface-mounted in order to weaken. These modules are produced as resistive or inductive according to where they will be used.

The power of the regional adjustment panels should be 5W, 10W, 12W, 20W, 30W, 40W, 50W, 75W, 100W. The sound level adjustment of the group adjustment panels can be made in 12 different positions.

Level 0 indicates off position. The stepped volume adjustment shall be manufactured in accordance with the infinite turn principle.

A 4-position commutator is used on the channel selection panels. Channel selector and zonal adjustment panels have 4-position commutator on the compact.