Bose Speakers & Power Steering

I have a 2003 Trailblazer and with the bose sound system and when you're sitting up front the sound is amazing but the rear speakers sound terrible, there is no bass what so ever...could there be something wrong, or does every trailblazer sound like this. I have another question, when i start my Tb and back out of the driveway once i turn out and shift in to drive, when i go to turn the sterring wheel back the engine dies down, and once it stalled, has anyone else had this problem, and what it the solution?

Blake Housel