Operation amplifier audio equalizer

[swuster]

Homework Statement

I am to construct a circuit which can provide variable gain for the bass, midrange, and treble frequencies of an input. One of the stipulations is that I should use as few elements as possible.

Homework Equations

n/a

The Attempt at a Solution

Right now the only solution I can think of is cascading three band pass filters, each with cutoffs for the frequencies relating to bass, mid-range, and treble, and each with variable resistors to change the gain, but I think there's probably a better way to implement this. Is there a way to separate the various frequencies so that I can connect three variable resistors in parallel and use only one op amp, as opposed to three?

 

[skeptic2]

Do you have a version of SPICE? There are various free versions available on the internet and it would be a good idea to simulate your ideas before building a circuit.