I have an Onkyo AVR with Audyssey 2EQ. Speakers are average, subwoofer is ancient but reliable; all-in-all an audio setup that is nothing special. Audyssey pretty much places the basic settings spot-on (double-checked with a RS SPL), so this isn't really a problem with Audyssey per-se as opposed to a conflict with my equipment.
Audyssey (or Onkyo) sets my global crossover setting to 150hz. While my speakers are capable of lower, this result is probably due to the non-ideal placement of the center channel speaker. Manual frequency sweep measurements done with the same speaker setup before with my older AVR (and without Audyssey) resulted in a crossover setting of 120hz, as that's where I found the roll-off to begin (again, thanks to center speaker). Now the problem.
I do not dispute Audyssey's results, however the LPF on the subwoofer itself is set to 150hz, the highest it can go. Back when I did the manual frequency sweeps, whenever the crossover settings in the AVR overlapped the Sub's LPF, there was a non-linear response within that frequency range. Now I have not tested it with the current setup, but the same result will likely occur, considering Audyssey does not know about the subwoofer's LPF effect. The subwoofer itself has a frequency response (tested and confirmed) of 20hz to 150hz.
Considering this, should I lower the AVR crossover to 120hz and live with the null below 150hz (probably just from the center channel speaker), and if doing so, does it throw off the entire speaker EQ or just where it was set to roll-off? Only an assumption, but if Audyssey EQ's the roll-off, and frequency response is being skewed by the overlap of the sub's crossover in that range, than there really isn't any EQ at all, correct?
Many thanks in advance.