Beheme, you should not consider this the end but the beginning.
Personally, I'm a little slow at making adjustments in my own system as it took me 9 months to find the 'ideal' speaker location. I've not moved them in almost two years and I'm sure I still don't have the optimum placement.
It takes me a bit longer because my speakers are sitting on Star Sound's Audio Points and my speakers are about 145 lbs. each. And believe it or not, there is a very real and very audible difference every time I move my speakers as it literally take 6 to 8 days for the Audio Points to properly settle back in or break in all over again with their connection to the floor. So with these 3 things, I'm always hesitant to move my speakers or my racking system.
Again, you only have a 7 ft ceiling, hence the greater the opportunity to reflect off the floor, then to the ceiling.
I'd like to suggest the thickest carpet pad underneath the thickest rug/carpet.
Keep moving the speakers around a few inches every few days to find an even more optimal location.
I don't know what speakers you have, but if your open to placement suggestions, I'd like to recommend this as a starting point:
Locate the speakers 5 1/2 ft. from the wall behind them and
2 1/2 ft. from the side walls. (All measurements are from the front/dead center of the woofer driver).
This should give you about 8 ft between the left and right tweeters.
Move your chair so that your ears are no further than 9 1/2 ft from either tweeter. This will give you a slight nearfield listen which usually is ideal anyway.
Toe the speaker in toward the center so that the tweeter axis crosses right in front of your nose.
If your rug leaves bare floor exposed anywhere in the front half of the room, throw some big cushions on the floor in the corners behind the speakers, and throw some cushions, pillows, or comforters/blankets (throw not folded) on the other exposed bare floor spots in the front half of the listening area (from the chair to behind the speakers).
You might even loosely spread out some thicker blankets on the floor to assimulate a thicker pad/carpet between the speakers and listening chair triangle.
Uppermidfi may consider this overdampening and he'd be right. But I'm just trying to offer a suggestion to demonstrate what your room might sound like if you had thick wall-to-wall carpeting and carpet padding.
Who knows, if you try these things and post saying this experiment brought a dramatic improvement, maybe uppermidfi will buy one of my racking systems. :)
One clarification I should make regarding my previous post. When I stated that the room's acoustics and treatments only account for perhaps 20 - 30 at most for a system's sonics, I also made that statement with certain assumptions or givens. Thick carpet padding and wall-to-wall carpeting is one of those givens.
Hope this helps,
-IMO