Op-amp tone stack

[BRSHiFi]

For a 3 band equalizer tone control circuit, where do you recommend I place the center frequencies for each band? What should I make the bandwidth for each control, aka the frequency range the bass, mid, and high boosts and cuts?

 

[Tekko]

Just google baxandall tone stack and you should find quite a few verieties of tone stacks.

 

[BRSHiFi]

Most of the baxandall results just show existing circuits. Worst of all they do not give information that answers my question.

http://www.analogzone.com/avt08063.pdf

This pdf is really helpful when it comes to designing narrow-octave equalizers, but I am just looking to do a three band equalizer for now.

For a 3 band equalizer, i simulated a circuit using gyrator band filters that have the following specs:

- Bass: Cutoff frequencies at 10Hz and 400Hz. Center frequency 63hZ.

- Mid: Cutoff frequencies at 400Hz and 5200Hz. Center frequency 1442hZ.

- Treble: Cutoff frequencies at 5200Hz and 30000Hz. Center frequency to be determined.

Do you feel this is a good design, or do you think I should place the center frequencies and cutoffs elsewhere?

 

[Tekko]

I've never dealt with tone controls.

 

[Frank Berry]

It's all about your preferences.
Typically, the bass and treble filters are of the 'shelving' variety rather than the bandpass variety.
Let your ears be your guide.

 

[mickeymoose]

What is the EQ for?
Take a piece of paper and show us on a graph (frequency vs. gain) what you want. E

 

[sreten]

Hi,

Search and you shall find. There is a relatively simple 5 band tone stack
based on the "Cello" recently posted, as well as simpler variants. Its all
been covered before, the ideal tone control is not remotely a new idea.

rgds, sreten.

 

[Loudthud]

There is a three band version of the Baxandall you can find on the LF353 data sheet: http://www.ti.com/lit/ds/symlink/lf353-n.pdf

There was an example with equasions in an old National Applications book, but I haven't been able to track that down.