I'm new in equalizers, very new in fact. At this moment, I'm trying to search for a 3-band Graphic Equalizer circuit for analysis. Any advice? or websites to recommend?
I tried searching and it seems that I only found 5-band equalizer. Does it mean that it simply goes in this manner? => 5 band means 5 op-amp used, whereas 3-band means 3 op-amp used? Sorry if I'm really talking nonsense here.
Hope no one will get mad. Help needed. Thanks in advance. Bye.
It could be made as 3 opamp with the frequency band adjusted to it. Normally when three is required you already have two of it that is Bass and Treble then what is required is midband filter which you will find as Precense control. That is why when a GEq is required one goes for a minimum of 5
Equalizers can be made as decade, tercet, octave etc. Each regulator has it's own frequency at which it boosts or attenuates the signal. It is usually realized as series resonance circuit with active inductor and gain regulation. All stages of equalizer follow the same concept, only frequency determining elements changes.
For study purposes it does not matter if you take 3 or more bands as an example.
There is another form of equalizer where you can control the center frequency, bandwidth, and gain. I think that this is called a parametric equalizer. It is used for mitigating the resonance effects of a large room.
See Attachment please ! Very basic equalizer schematic...
Description :
Using a single op-amp this easy to make equalizer offers three ranges, low frequency,mid frequency,and high. With component values shown there is approximately +/-20dB of boost or cut at frequencies of 50Hz, 1kHz and 10kHz. Supply voltage may be anything from 6 to 30 Volts. Maximum boost 20dB is only realized with maximum supply voltage.
Above circuit is a simple tone control with separate bass, treble and mid tone controls. Graphic equalizers are something like this circuit: **broken link removed**