shurster, are you talkin about the satellite audio streams or the internet ones or both? wouldn't it be nice to see some spectral analyses or FFTs or super-nifty lissajous patterns subtracting the original signals from the received/reconstructed signals on a channel-by-channel-basis? i suppose only the siriusXM engineers get to see those.
usually i listen in car or on TTR1 or headphones/iphone and find the audio quality to be fine for the original-Sirius music channels, at least . i haven't listened to XMU much however, or any of the XM music channels. tonight i'm amplifying the iphone output via my ancient monster DCM timeframe speakers & large old amp... when i crank it, it sure does sound "muddy" or "too compressed". that's as far as i can pin it down for now as to what my decibel-addled/nonprofessional/rock-concert ears notice.
however I find the TTR1 so awesome that i'm looking at all sorts of other internet-wifi-players - primarily for siriusXM but for whatever else too, that spotify, dogify, catify, whatever it takes to get some decent audio quality.
for example, any recommendations for which is the web site/stream which the maximum-bandwidth-consuming/maximum-quality good-old-grateful-dead audio streaming?