Active Equalization for Subwoofer help

[kaytata]

I built 2 eminence alpha 15a in h-frame as per Martin J.King's design (http://www.quarter-wave.com/OBs/U_and_H_Frames.pdf).


The frequency response graph shown in the document(pic attached) suggest a need for a 4-6db cut around 100hz, and perhaps a 6db boost at around 25hz.


I've been looking at ESP Eight Band Sub-Woofer Graphic Equaliser

wondering if it is possible to implement a part of the circuit i.e. just the two bands i.e. 25hz and 100hz.
And perhaps a fixed resistor instead of a pot for a 6db boost at 25hz and 6db cut at 100hz. The circuit examples given in this documents are attached below.
I also plan to use the ESP 2-Way Linkwitz Riley Crossover set for 100hz for the same. From 100hz and up I will be using Elac B5.2.


Any help from any of the experienced forum members would be very much appreciated.



Regards,
Kay

 

[bjorno]

Hi kaytata,

Rec:You need a PEQ=Parametric EQ, not a Third Octave Graphic EQ

PEQ vs Graphic EQ

A good textbook One Section DIY analogue PEQ can be found here:

faktiskt.io • Visa trad - Julklapp fran Morello's lab.

faktiskt.io • Visa trad - The Morello PEQ

Use Google Translate!

Use HR Hornresp Program to find out the needed PEQ settings.

b 🙂

 

[kaytata]

Hi Bjorno,
Thanks a lot for the fast response. I will take a look if I can grasp it.
Kay