Where should i set my ssf filter to on my saz-1500d? Using it to push a AQ hdc in a 3.5 cube box tuned to 38.

I say around 35hz

Wait, the HDCs have a longer suspension than ordinary drivers do.

Get or make a test tone disc with frequencies 28-40hz on it roughly.

Start playing at 38hz and work your way down.

When the sub appears to be moving more than what you think it should be moving, start to increase the SSF until it stops moving dangerously.

DJ has told me those drivers can play a good amount under tuning before over-doin it.

Wait, the HDCs have a longer suspension than ordinary drivers do.

Get or make a test tone disc with frequencies 28-40hz on it roughly.

Start playing at 38hz and work your way down.

When the sub appears to be moving more than what you think it should be moving, start to increase the SSF until it stops moving dangerously.

DJ has told me those drivers can play a good amount under tuning before over-doin it.

so start wit the ssf at 20( all the way to the left)?

Not to nitpick, but they aren't Sub-Sonic Filters as that would imply they are slower than the speed of sound. They are Infra-Sonic Filters. Set it at 32-38 Hz and you should be fine.

I'd set it lower. In fact, I have mine off on my box tuned to 30 hz and never had a problem. The thing to remember is that the frequency you set it at isn't where the slope begins to roll off, that's the -3db point. so if you set it at, say, 35 hz, it will begin to roll off higher than your tuning frequency, which I doubt you'd want. I'm just saying if it were me I'd probably set it at less than or equal to 25.