Had a chance to play around a bit with the tone controls in my RF. (On a side note the Bluetooth audio has been working brilliantly, with auto-connects in less than 15 seconds upon starting the car).
Start by setting all tone controls to the "0" position. Going MAX on bass/treble will result in over-processed sound.
My favorite settings, after experimenting and doing some tweaking, is as follows:
BASS +1 (0 is a bit too thin, +2 over-emphasized)
TREBLE 0 (sounds great as it is in my opinion)
BALANCE 0 (perfectly balanced)
FADER -2 (notice how you turn it to -11 and there's not much sound output from the rear? As you work your way back to 0, notice how you get a bit more subwoofer response; but when you hit -1 the front speakers seem overloaded?)