The Nissan Path

Hi Everyone - Just got my Pathfinder over the weekend. I'm smitten.

I'm a bit of an audiophile, so I noticed the XM radio sound quality is pretty poor. It's not an EQ issue because all other audio sources sound great. Is this a known issue, and/or is there a solution?

Bonus question: Anyone know of an after market subwoofer that fits in place of the factory Bose sub?

It's XM, satellite radio only broadcasts at "near cd quality" and that's why i have never subscribed, it sounds like piss to me.