Just like in realesatate...Location...location....location.

First: Room set-up. Sounds like your seating position is a bit far from "everything". General rule of thumb. Make the seating position the same distance from each speaker as they are apart, making an equalateral trinagle. I know you have a large TV but that's not big enough for 12-1/2ft.
Secong in the 13ft wide space you should be able to get your speakers about 8-1/2ft apart. Toe the speakers in slightley so that they aim just behind your seatin position. This will give you a good compromize of detail and sound stage.
Third: Don't forget all speakers need a little break in. Try running a good bass track (Bos Scaggs 'Thanks to You") through the system for at least 24 hours (just loop it). After that the whole system should warm up considerably. You can expect the system to loosen up after another 3 to 4 month of normal use (4 to 6 hours a week).
Try this and I know you'll hear a notable difference.