XM Radio has no fidelity...sounds filtered

Our new 2007 Escalade XM radio sounds horilble.......Our 2003 model sounded great, so i had no reason to reallly listen to the new one before making a decision to buy.

The sound is muffled or filtered....does not sound clean. You really have to turn the volume before getting any "Pop". The FM stations and CD player sound great.

Has anyone experienced any problems like this?

Thanks

I find the XM radio sounds great in my '07 with the DSP set to Surround.  My only complaint with the radio is it doesn't tune the FM stations as well as any other vehicle I have had.