Good speakers make a big difference (I went with Polk) but, with the factory head unit, the soundbar speakers are basically putting out mid-range only. Even the dealer brochure for my '11 makes mention of it. I do not have the upgraded sound w/sub though. I haven't heard of a way around this other than putting in an aftermarket head unit.
Now: '11 JK Unlimited Sport - Natural Green
2.5" BB and RK Disco's
Stubby bumper kit w/light bar in front & Rugged Ridge XHD in back
In the past: 05 WK, 02 WJ