What should be included in a subwoofer lowpass filter?

JanErik

Member
2010-08-09 9:35 am
Vasa
I am about to design an adjustable lowpass filter for subwoofer, including these features:

- Summing both incoming channels after buffers
- Sallen-Key for easily adjustable crossover frequency, 24 dB/octave. Would you use trimmers/potentiometers or just jumpers (maybe four selectable frequencies)?
- Differential output for easy inverting and bridging.

Is phase correction necessary?
How about subsonic filter even if I dont play vinyls? Maybe doesnt have to be very steep?
What do you think about this circuit: P48 Sub-Woofer Controller (Rev-A) ?
 
Last edited:

JanErik

Member
2010-08-09 9:35 am
Vasa
I am now finalising the circuit and starting to draw a PCB. It will be adjustable to the extent of replaceable resistors in IC sockets, not by trimmers. The subsonic filter will be simplified with only 6 dB/octave

But is a phase control necessary or would a simple invert switch be enough? Perhaps the phase control also does more harm than good? I have been looking at this: Project 103 - Subwoofer Phase Controller .