Subwoofer filter/ EQ help

Someone gave me a Hifi subwoofer box with its 12" woofer. Brand unknown, amplifier and filter/Phase circuitry fried.
I managed to build Rod Elliot's P3A. Works great!! I now need to build a circuit that has filter adjustment, phase switch, etc.
The box is ported. Thinking of keeping it ported, as the driver has 3rd harmonic when i feed it with 20Hz.
Any ideas on a nice circuit to build for this diy sub??
Thanx in advance.
 
Someone gave me a Hifi subwoofer box with its 12" woofer. Brand unknown, amplifier and filter/Phase circuitry fried.
I managed to build Rod Elliot's P3A. Works great!! I now need to build a circuit that has filter adjustment, phase switch, etc.
The box is ported. Thinking of keeping it ported, as the driver has 3rd harmonic when i feed it with 20Hz.
Any ideas on a nice circuit to build for this diy sub??
Thanx in advance.

Hi didi,

Do a Forum Search.. Start with looking further down at this page, i.e. at 'Similar Threads':

Here is an example:

http://www.diyaudio.com/forums/subwoofers/176683-subwoofer-input-filter-eq-circuit.html#post2356623

b:)