Any of you have your sub behind one of your fronts? Does it work well?

Whether or not that placement of a sub works well depends almost entirely on the shape of your room, what's in it, and where you sit in relation to the sub and speakers.

As with anything placement related, experimentation is a worthwhile and often rewarding endeavor. Give it a shot.

Behind the speaker just may be the best location in your particular room. You never know.

Do the tried and true "crawl" test.

Put the sub right where you sit (your sweet spot for listening). Now get on your hands and knees and crawl around the room until you find that the sub sounds the best. Not boomy, not faint, but nice and smooth. You can try various test tone sweeps, repeating audio clip, etc. Once you find where you think that the sub sounds good, but you sub in that location, and you should be pretty much set.

Now, if you have a specific reason for putting the sub behind the speaker, then that may have to take precidence over what sounds ideal.

I know that while I am building v3.0 of my home theater, my fear is that the one location that my sub will fit won't give me the best sub sound and response, but I am kind of stuck with it at this point. No way to test until the room is done, and at that point, there will be no other location to put the sub, so I may have to sacrafice ideal sound for the limited location option (only one) that I will have.

Experiment a little. Have fun crawling around!

Somewhere I read this described as the '6-pack test'. Get a six pack and place the sub as you describe - where you plan to sit. Then crawl around the edge of the room leaving cans where it sounds best. Then revisit each can in turn listening for the best, draining them as you go. Viola! Great placement!

-Brian n8wrl