Originally Posted by LoudandClear
I must say i'm disappointed in the SQ on XM. I got a free 3 mo sub in my Cadillac and I signed up for a year because I loved the extra channels with no commercials but the SQ does suck. My caddy has a decent sound system and CDs sound much better and a fair comparison was when I had the same cd in my car as what's on XM..... compared the 2 and the XM sounded dead. No punch, very flat.
I don't think it's just because of the bit rate because I played a CD with recorded MP3s for comparing. I think the music signal from xm is intentionally compressed to make it sound ok on earbuds with out distorting when played loud. They reduce the dynamic range which removes the peaks and fills the valleys more so the chaep earbuds can handle it. Sounds like crap on a decent system though. Some refer to this as increasing the loudness.
It's actually hard to reduce the dynamic range on pop music any more than it already is because most CDs are produced with unbelieveably little dynamic range (less than LPs had). CD's have a capability of 96db of dynamic range, but no one uses it because everyone wants their record to sound the "loudest", no matter how bad it sounds and how much listener fatique it causes.
Don't confuse audio compression (reducing peaks) with file compression (reducing bandwidth).
I was at a producer session at the Audio Engineering Society convention a few years ago and one of the producers surmised that if dynamic range was reduced as much as it is today back when the Beatles became stars, he wondered whether they would have been successful. He maintained that fatique would have set in listening to their music. Interesting point.