Originally Posted by SherazNJ
Well then for the next few weeks I'm going to keep on checking if there is any crack coming up :-). If I see any then I'll just turn the gain a bit low.
BTW, I know that once calibrated with Audyssey, it is strongly not advised to turn sub trim in avr below what it sets. It is ok to turn it up but now below. If I want to turn a bit low, I can use gain knob on subs. If I do that, do I have to re-calibrate?
I never change the subwoofer gain controls after running Audyssey. It's too hard to go back to the original point on the gain setting, especially with amps that don't have detentes on the gain knobs. If I want to raise or lower the levels of the subs, I use the subwoofer trim controls in the AVR. You can do anything you want with the sub trim in the AVR. Just record where it was when you started so you can go back to the "calibrated" level very easily. (I do try to avoid "positive" settings. It is possible to overdrive the inputs of some subwoofer amps with too high a signal. As long as you stay at 0 or below, that should never be a problem.)
I think what you are referring to is that you shouldn't lower crossovers
below what Audyssey sets them to. You can raise the crossovers, but if you lower them, you'll no longer have correction below the crossovers set by Audyssey. Audyssey measures the -3 dB point of the speakers. It sets the crossovers to the next highest available crossover above that -3 dB point. It won't go lower than the -3 dB point because the only "correction" it could apply there is boost. Boosting low frequencies below the point where the speakers can practically reproduce them is dangerous to the speakers, and Audyssey won't do that. Since the speakers are rolling off their response below the -3 dB point anyway, there is nothing to be gained by lowering the crossovers.
OTOH, it's fine to raise the crossovers, as Audyssey will still apply room correction above the -3 dB point.