Subwoofer Placement

I have no room between my front channel speakers (b&w 803 diamond 2s) and the side walls of my living room. So, to incorporate the sub, I have two options:
- get a sub like the Rel T9 and place it a few feet ahead of my left tower speaker (the sub would be 4 feet in front of the speaker and 10 feet away from the listening position as I have a long, rectangular living room)
- get two smaller subs and place them directly behind my two front channel speakers. I have only 10 inches of space between the back wall and the back of the front channels. Question here is will this impact the sound from my front channels and will the subs still sound good given they are not in hype open?

Thanks for your consideration.
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Thanks Bob. I have room to place the sub next to the side wall, but it would have to be in front of the speakers.

Thanks for forwarding the paper. Very detailed analysis, but not directly applicable to the problem at hand.
Of the two, I'd go with option 1. I wouldn't place sub-woofers behind your L&R main speakers especially with only 10" of space. This could impede the LFE's eminating from the two subs. Placing one sub 4' out in front of one the two main speakers would be the better location if that's all you have plus 10' away from the listening position is a good distance. I use two B&W ASW-610s for my rectangular room with a pair of B&W 683s as my mains. Both subs are apart from each and they balance the LFEs beautifully. If you could find space in your room for this approach, that would be best IMO. I'd consider using a B&W subwoofer (DB1 for example) which is part of the 800 series. If you don't need that much output, the ASW610XP may also be a great choice.
Irrelevant, but my bud mounted sub under the passenger seat of '13 Toyota Tundra. When he cranks his system up you can feel agressive vibrations under your arz :-).
Thanks for the light hearted post Czarivey.

Pdn - thanks for the feedback. I agree with you. I like Rel because they do just one thing, and do it well. Plus, I don't want a big sub, for space and cosmetic reasons, and that's why I liked the Rel T9. I also believe Rel is the best sub for both stereo and home theater applications.