Resources for building a 3 band Eq

I am currently working on building a 3 band equalizer and am having trouble finding information on how to do this. I have found many schematics online of the equalizer, but I cannot find anything that explains how it was designed.
I have attached one of the schematics I found and it is the one I'm currently trying to analyze. I would greatly appreicate some assistance with analyzing this design, or even a new design in general. Thank you.

Hi

See attached for explanation on spectrum analysers,graphic equalisers and bandpass filters this should throw some light on the subject for you

Mark Harrington

www.harrington.force9.co.uk

Or if you are really lucky you might if they are still available be able to get your hands on this ic

LC7060 These days this is done using dsp I cant help you with that at the moment You need to look into dsp pic micro for answers re this

Sanyo semiconductors

SEE ATTACHED FOR ALL INFO

Is there a DSP PIC that is fast enough to operate at the full audio spectrum at full 16Bit or even 18Bit resolution?

I ask, because this is a technology I would like to explore (i.e. music synthesis), but when I took a cursory look at the PIC line of DSP microcontrollers, it didn't seem like they were designed for high quality audio. But, if you know of such a beast, I would like to hear about it.