Originally Posted by Locoelectrician
AVR-3310CI, 2 crown amps, Behringer dual 31 band EQ, 2 18s and 2 15s. Trying to figure out the best way to set my system up properly. I have the sub output split and going to each channel of the behringer EQ. Each EQ output is split and goes to its own Crown amp which powers a pair of subs. I figure there is no way for Audyssey to properly handle this so what I've done so far is set up my DB meter, pick a target DB of 95, and play test tones while adjusting the EQ to archive as close to 95 at each frequency I can get. I did it once with just the 18s powered and once again with just the 15s powered.
Start around 67dB as opposed to 95dB.
The following is my drill. Do with it what you will.
Setting dual subs, I use the sub's gain to separately (all other subs turned off) set each subwoofer's test tone output, at a measured 39" or 1m, to 67dB. If I were running four subs, I'd dial it down to 65dB @ 1m. Doing this offsets the combined subs room gain. Now that the subs have been balanced at 1m, balance their output a second time at the main listening position so the output of each sub is individually the same at the main listening position; 65dB. The combined total of all the subs running, at main listening position, to keep Audyssey happy, should be in the 70-73dB. In my opinion, the subs are now balanced and ready for Audyssey to be run.
The above is an imperfect science/art as each room has it's own room acoustic characteristics (gain) so the final result will be dictated by how the room responds to the combined subs output; the need for user intervention.
When Audyssey has been run, go into the AVR's main menu, to the Audio section, bring up the subwoofer slider and adjust the subwoofer channel, all subs running, at main listening position, to 73dB. Yes, that's an odd number which is purposefully intended to split the difference between 70dB and 75dB; the two reining standards. Now the subs are balanced and what you hear is up to how your subs interact with the geometry of the room; acoustics. If you want better, you'll need to add the likes of a product known as "DSPeaker, Anti-Mode, 8033" to deal with modes and room treatments to deal with nulls.
Hope the above is found helpful.