Single Sub Position

I agree with @tmortsd, I always had mine to the rear & in the corner of my old house. Then moved to where I am now & put it to rear right on the side of the couch. I the bought another sub, but smaller & put it on the other side of the couch & it brought attention to itself, so i dropped it. Recently I moved it to the rear of my chair & that helped with the sound, Last week I did an update to my Onkyo & purchased the Dirac Live download & it blended all my speaker with the sub.

I also have 2 subs for my analog system, (up Front) to help from there. The only thing about that is, on some recordings it's just to much base. So I'd have to go & lower it. Bottom line is, find your sweet spot & enjoy your system.

Right behind my listening position works best for me.  Can keep it turned down enough to not muddy up the sound of the main speakers but still feel the thump in my back.

I think these posts show what we have always experienced at Lone Mountain and TransAudio- each room is different and where "the subs go" is just as different as the room itself.  Ive almost never had the same location work out in two rooms- especially in untreated or undertreated  rooms.  Drives some people mad as the desire for visual symmetry is strong- even to the point of choosing a lesser performance location. 

Brad 

I've never been a fan of subs because I just couldn't really get them to sound right / integrate the way I wanted, until, I placed an SVS PB13 Ultra directly behind my listening seat pointed at my back.  Omg, listening became a visceral experience.  It sounded amazing.  I bet the 4 sub setup sounds good too.  I forgot what it was called. But basically get 4 subs and place them in all different spots to smooth out nulls and peaks and to gain headroom.

Nicely done!  A little crawling goes a long way.  I’d highly recommend getting a second sub whenever possible.  Leave the first sub where it is and do the crawl again to find another sweet spot for bass and you’ll be in for a treat.