question About XM

PrerunnerGreg · 01-01-2007, 08:51 AM

This is just a general question about the sound qulaity of XM. Here's my situation, i received a roady xm receiver for x-mas. Tried it in my wife's xterra (has an Alpine 9856 HU) with the fm modulator....horrible sound. Not a reception issue, but sound was compressed, treble just died, phase issues. So, thinking the modualtor is the culprit, i used the Ai-Net as an aux input and used the line out of the unit, so we are now wired direct. not as much of a phase problem, but still horrible sound, worse than fm sound (a lot worse) and a far, far cry from CD quality. So i went to the local BestBuy, and listened to all the display units on hand, they all sound just "ok", even with thier high-end seperates and amps, its hard to judge as i didnt bring a cd and the guys there are helpless. Now, im a pretty picky person when it comes to sound quality, but i know that it shouldnt sound this bad. But are these xm units all this bad? i really like the programing, but its not listenable unless its talk radio. Any other audiophile types found this to be a problem? Are some receivers better than others? As i said, im not looking for the best sound imaginable, but just acceptable, beyond a hand-held trasistor unit. Should the sound be at least as good as FM?

bestatchess · 01-01-2007, 09:18 AM

Not as good as CD as XM is compressed using something like this:

http://www.codingtechnologies.com/products/aacPlus.htm

FM has the high end limited to about 15Khz, but it can sound good if you don't have good high frequency hearing. (alot of adults fall into that category)

TexTheTitan · 01-01-2007, 09:51 AM

I have the Samsung portable XM receiver that has a cradle for the truck and one for the house. When I have the AUX cable plugged into the cradle, the sound is not that great. So I plugged the AUX cable directly into the unit itself. This seemed to help.

Does that make sense?

loosenut · 01-01-2007, 09:55 AM

I have the stock XM setup in my '05. I think it sounds just fine.

gratefullife · 01-01-2007, 10:25 AM

Quote:

Originally Posted by TexTheTitan

I have the Samsung portable XM receiver that has a cradle for the truck and one for the house. When I have the AUX cable plugged into the cradle, the sound is not that great. So I plugged the AUX cable directly into the unit itself. This seemed to help.

Does that make sense?

Wife has this same one..so it sounds better with the aux straight in than with the fm?

Sammy Sandbag · 01-01-2007, 12:11 PM

I'd say that my Sirius doesn't sound as clear as a strong FM signal, and definately not close to CD or even MP3. Like BAC mentioned, it's the compression they use. I learned to live with it just because the selection is so good + no commercials.

PrerunnerGreg · 01-01-2007, 12:27 PM

Thanks guys, seems to be what im facing here. Ive heard from so many people how great it is, i think my expectations were a bit high. i might try a different processor before i give up though. Ive grown used to the limiting factor beign the speakers and power, not the signal source. Was it too much for me to think that my direct TV sounds pretty good and i was hoping for the same here (both being newer technology from a satellite transmission). Oh well, back to the 'ol stand-by....CD's.

ruauman2 · 01-01-2007, 02:26 PM

I think that almost anyone that is an audiophile may find the compression of the XM/Sirius music to be lacking in quality. This is probably true of MP3s as well which are typically a 128k sample rate. I'm not sure what the satellite sample rate is, but I'm sure it can be easily found on the web. It may actually be worse than 128k.

Someone will correct me if I'm wrong but I think you may want a sample rate of at least 192k to get "near" CD quality from your music.