I have seen a couple of suggestions for adjusting my speaker placement. Not sure why that came up in this thread, but its a valid suggestion. Here's the deal though, my room is a cube: 10x10x10. If you lay that out on the ground, you will immediately find out many options employed in larger spaces just aren't available here. My Klipsch speakers get boomy and the stereo image gets flat as a pancake if I place them close to the walls. Also, if close to the corners, that boomy bass thing happens.
That drives me away from the back wall and side walls as far as I can get. At the other end of the room, I can only put my listening chair just so far back. If I'm too close to the back, I hit a node where there's no bass at all. Scoot forward a bit, and the bass comes back.
I have taken the "golden triangle" thing and moved the speakers all the way from the corners (not good) in small increments all the way to where they are now and then some non symmetric placement as well. For a small room, there are a lot of variations to try. I spent a fair amount of time, days actually, experimenting with not only placement, but height and toe in (or toe out) as well.
After all that moving and shakin', I ended up where I am now. When I crank back the home theater listening recliner, my feet are actually between the speakers. I have a near perfect (to my humble and care worn ears) stereo sound field that is very pleasing. The downside is the sweet spot is very small.
I hope when the Salks arrive I can do some more experimenting (for sure) and get them pushed back and further apart. The only question will be : do I buy a new amplifier just because I want one?
Since all of this relates to sound quality, it matters. Your room being a cube doesn't help, either. If you haven't done anything to absorb some of the sound, I would highly recommend that, too. Small rooms have issues that don't exist in larger ones and in a cube, the room modes coincide, causing additional problems.
If you haven't used Room EQ Wizard (AKA REW), you might want to download it and look at he tool for modeling speaker placement. It allows for lateral and vertical placement, number of speakers, subwoofer(s) in 3d and shows a predicted response. It's an interesting way to experiment without needing to buy a lot of stuff that might not work, might be expensive and might not meet with approval from The War Department.
I used REW when I came to the conclusion that I really hated the sound of my system and I wanted to do something about it. Actually, hate is too strong- I was annoyed by the cancellations that caused me to sense a strong pressure difference when I moved to one side or the other. I couldn't find a spot where I really liked the sound of the low end and when I looked at the response in REW, I saw a big suck-out in the mid-bass. I had made some acoustical panels for a job and kept the leftovers, so I watched the screen as I moved one into place, followed by another, and another, etc. Eventually, I no longer had the suck-out and I immediately had a brand new system- huge (yuge), tremendous difference. However, that wasn't the end of the exploration. Something still wasn't right, so I eventually marked the existing locations and measured the distance from each speaker to the back wall and found the angle to my listening position, then made them equal. My speakers aren't on the centerline in the room, so that had eliminated one problem but they really came to life when I hit the sweet spot. I found this by setting the balance control to one side and listening to that speaker, noting any small differences (and large) that I heard. I kept REW running and watched the response and avoided any locations that caused deviations from smooth/flat and repeated this for the other side,stopping to listen many times before setting the balance to the middle. I used green easy-peel painter's tape to mark the speaker's corners and made some small tweaks before deciding to spend some time with the speakers in that position.
My sofa is against the back wall, but I move around and listen for differences in the sound- the low end is much more even throughout the room and I haven't used my subwoofer in years. I can feel the bass in the floor and through the sofa cushion at times but, having done car audio for a long time, earthquake-type bass neither impresses me nor is it what I want. I find that I'm far less neurotic about the low end, now that I don't use a sub, even though the low end starts to roll off at 38Hz.