Equlizer Project For Controlling wide band of Frequency.

Here is the Preamplifier unit for Sub-woofer and Central speaker.

For the separate channel of the Treble and bass sound, They have variable resistor for controlling the gain







 For controlling each channel such as Balance, Volume, Bass and Treble, they have included quad OP-Amp per each section using UPC4558

The variable resistors are enabled dual controlling functionality for the Bass and treble sound. Entirely four variable resistors are used for controlling left and right channel.

Seven Band Graphic Equalizer system for Front speakers.

Back side of PCB

By using few comparator, we can make the controller with wide band of frequency.

Single PCB for one channel

double PCB for stereo

This circuit can control only 7 band of the sound. For buffer of the sound, they have used NE5534 op-Amp.