# Multi Sub Setup Workflow



## hjones4841 (Jan 21, 2009)

I need advice on workflow for setting sub distance for two scenarios for locating 4 identical subs. Room is symetrical, sub placement will be L/R symetrical for both scenarios with the primary listening position centered L/R but back from F/B center a couple of feet. All will be driven from the same LFE output of AVR.

First, the workflow for a co-located pair in front of L & R, near the corners:
1) Bypass BFD. 
2) Match sub levels individually using sub volume controls.
3) Run Audyssey for distance setting. What will Audyssey do since there is now a phantom image? Will it calculate distance correctly, or should I do it manually? If manually, do I set distance to the known physical distance to the sub pairs or to the center of the front wall, the supposed location of the phantom image?
4) Unbypass BFD, add a foot to the sub distance for its delay & EQ.

Second scenario for one sub in each corner of the room, in front of LF, RF, LB, RB:
1) Bypass BFD.
2) Match sub levels individually, this time for equal SPL in the main listening position.
3) Run Audyssey for distance setting. What will it now do with a phantom image centered at the listening position? Or, what manual distance should I input? The average distance to F and R? Or, should I set distance based on max combined SPL with LF pink noise?
4) Unbypass BFD, add a foot to the sub distance for its delay & EQ.

Thanks for your input.


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## drdoan (Aug 30, 2006)

The THX website suggests placing 4 subs, one in the center of each wall respectively. You might want to check that out and read more there. Dennis
http://thx.com/home/setup/speakers/sub.html


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## hjones4841 (Jan 21, 2009)

Thanks, Dennis. I had read another recommendation like that, but the room is too narrow to allow that.


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## drdoan (Aug 30, 2006)

Can you co-locate 2 on opposing walls? Dennis


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## hjones4841 (Jan 21, 2009)

Not on the front/back dimension due to a large center channel speaker in the front and a fireplace in the back. Side to side may be possible, but only near the rear of the room, essentially to the side and behind the recliners. Interesting idea - that would almost be nearfield for the outside seats...


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## drdoan (Aug 30, 2006)

Obviously, the best thing is to try a couple of setups and listen to the best one. Dennis


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