Originally Posted by chrisreeves
Forgive me if this question has already been asked - I tried to search the thread but didn't see my key phrase come up, despite a number of hits in the search.
Question is this: I'm looking at getting a new AVR soon with dual subwoofer outputs, Audyssey XT32 and Sub EQ HT. But I want to run a four subwoofer configuration. Can I hook up two subs to one output using a y-splitter, two to another output with another y-splitter, and then have Audyssey do its subwoofer calibration?
Or will it screw it up because it thinks it is measuring one subwoofer at a time, when in reality it is measuring two at a time?
For what it is worth all four subs will be identical and will be placed around the room to smooth out bass response.
I have this exact configuration--the Denon 4520 and four identical Hsu ULS-15 subs. I have it configured exactly as you have suggested, a pair of subs on each channel.
I would like to add several more tips: Make sure each sub pair is gain-matched. To do this, play the AVR pink noise level-setting tone for the sub channel, turn off one sub, place an SPL meter a couple of inches in front of the dust cap of the other sub, and adjust the sub's gain to something close to 90dB. Repeat the process for the second sub, making sure its gain achieves the same 90dB reading. I use 90dB for the near-field measurement because this results in ~75dB at the MLP. You will be asked to set the sub levels at the beginning of the Audyssey calibration, so if the 90dB gain matching registers higher or lower than 75dB +/- 2dB in the calibration, go back to the gain-matching step and adjust both sub gains slightly higher/lower (preserving the gain-matching, of course).
And second, since Audyssey can only set one delay (distance) setting for each of the two sub channels, try and place each sub in a sub pair equidistant from the MLP. For example, one of my sub pairs is placed on the front wall at the 1/4 and 3/4 spots, both the same distance from the MLP.
And finally, if you have the measurement tools, you should follow the "sub distance tweak" procedure to ensure the subs are in phase with the main speakers. The procedure ids described here: https://dl.dropboxusercontent.com/u/...Oct%202013.pdf