A DEQ with no threshold is pointless
Originally Posted by carp
; a threshold is what makes it dynamic, otherwise it is just PEQ. Just thought I'd mention it!!!
A ratio of 3.5 works pretty good for a subwoofer, less than that will probably be too weak, and more than that might be aggressive at low SPL's.
You want the Attack and Release to be as short as you can make it without causing audible noise, 120ms and 500ms is a good starting value.
Also, if you want it to extend all the way down to 1hz you want to use a Shelf, not a BP filter.
A threshold value above -10db is dangerous. Its value should not
exceed the gain, otherwise you could clip the DSP.
Avoiding clipping is the whole point of using DEQ vs PEQ.
PEQ is dumb and will keep boosting even when the DSP is already clipping. A properly set up DEQ will deactivate itself and allow the system to resume it's native response just a few db's before clipping or over excursion occurs.
If your DSP has the horsepower and your gain structure is optimized, there is no reason to ever use PEQ. I'd replace them all with DEQ's (starting with the deepest frequencies.)