XM Radio issues

[Serendipity]

Any XM Radio listeners notice that on 20 on 20, 90's on 9, The Pulse, BPM 81, or Area 80 there is quite a bit of distortion in the low-end?

BTW, this is only when hooked up to the 2 channel rig. I also experimented with/without using a sub with the Definitives (in the past, I didn't use a sub for 2 channel listening) and had to lower the sub -6db @ 9 o'clock on the dial. At this point I have removed the sub from the 2ch rig and still have the distortion.

I also don't experience this when using computer speakers.

[Serendipity]

Anyone?

I'm thinking this is an XM Radio issue as I don't have any problem with CD's, tapes, or FM Radio.