Need to build a 3 band EQ around an ambler mid

[JAY X]

Hi!

That is the question: I need to build a 3 band EQ around an Ambler tilt mid. The question is what kind of Eq to build around this tilt mid? Two Baxandalls/shelvings (HI / LO), two filters.. (HPF/LPF)... ¿What could be more useful within the limitations (Only 3 knobs and 3 switches)...

Jay x

 

[abbey road d enfer]

HPF is the most important. Takes one switch for single frequency. I would choose oneswitch+one pot for variable 12dB/octave HPF. Atually, you may not need theswitch if you accept the idea of having the HPF permanently on and turning it at the lowest frequency for some kind of bypass. 20hz to 200Hz is ok for me since there is nothing useful happening below 30Hz, unless you want to do surround sound for seismic catastrophe film.
I would add a sweepable mid from 200Hz to 6kHz with a bypass switch and and "Q" switch.
IMO that would complement perfectly the tilt EQ that takes care of the LF/HF balance.

 

[JAY X]

Hi!

Interesting!. I found a sweepable mid schematic with switchable Q. I will post a schematic and see how i can change the values to this 1:30 ratio.
(200hz-6000hz).
All the stages should be in series, so, first comes the HPF, then the sweepable mid and finally the hi/lo ambler.?

 

[JAY X]

Hi!

The schematic i posted above, ¿Is a wien bridge type?

 

[abbey road d enfer]

Hi!

The schematic i posted above, ¿Is a wien bridge type?

Some would say it is, some would say it's not.
A true Wien bridge is actually passive, but it's almost inevitably used in conjunction with an active stage.
This circuit is a variation that uses some properties of the Wien bridge but it's a distant cousin.