[RCM]

Greetings experts-

Is it possible to use XM radio as a decent source?

Is there a way to decompress the signal, or maybe hook the XM directly to a headphone amp, or...?

I'm starting with a set of AKG 701s and will be building from there, so I have no amp or anything else yet, but I'm a big fan of XM except for the sound quality!

Appreciate the help...Rod

 

[blessingx]

Welcome to Head-Fi.

The short answer is no. The long answer is likely no, but there's some talk of dynamic range expanders & subharmonic synthesizers that may help. Also people seem to like the Polk home unit. I have Sirius, but the SQ is pretty bad in both and differences not that great. I find headphone use impossible, but it's great for auto use or home stereo cause listening.

 

[Downrange]

Quote:

Originally Posted by RCM /img/forum/go_quote.gif Greetings experts- Is it possible to use XM radio as a decent source? Is there a way to decompress the signal, or maybe hook the XM directly to a headphone amp, or...? I'm starting with a set of AKG 701s and will be building from there, so I have no amp or anything else yet, but I'm a big fan of XM except for the sound quality! Appreciate the help...Rod

XM is around 128K, I believe, about the same as iTunes downloads, but it doesn't sound that good, probably due to lossy compression. I don't think there's any way to "fix it" to make it sound much better. What I think it's good for is as background music or coverage of some sports, etc. In a car, unless it's not running, the sound environment is going to be too poor to hear how lacking XM is, but at home, it's never going to shine.

I also use it to find music I'm interested in hearing, then order that music on CD, or whatever... It's not THAT bad, really, just don't expect miracles.

 

[blessingx]

XM broadcasts at ~80kbps for important music channels, ~40kbps for the rest (~64kbps is used in reporting averages) and 32kbps for the talk channels. This is AACplus. Although AACplus is vastly superior than MP3 at low bitrates, I don't think 64 comes remotely close to 128 LAME VBR MP3 or the 128 AAC that iTunes store uses. Sirius (my pref) uses a difference compression system, but either way they both suck in SQ. Other advantages though.

 

[Max F]

I have a Squeezebox so now I can stream XM radio from the internet to the stereo. It sounds better than my little myfi xm player hooked to my stereo. Still far from CD quality. Adequate for background music though. I'll have to look again at what rate it's streaming from the internet. I do know that it WMA and not MP3.

 

[uofmtiger]

I believe that 64kbps is the max out via computer. The codec compression from satellite to the Myfi and other units is dependent on the channel. XM has been known to be very protective about the exact compression they use on each channel. The guesses that I have read about say that the music channels (via satellite) are probably over 64kbps and the talk channels are compressed more.

From Stereophile (1/15/06):

XM has traditionally been reticent to reveal technical information about its bit-rate and its codec specs, presenting these as proprietary issues in a competitive environment. However, many observers (ourselves included) suspect that the true figures are just plain embarrassing. Divide the available bandwidth by the number of channels and each XM channel would seem to be providing data at a mere 64kbps, a bit rate well below the lossy 128kbps that makes the average MP3 recording sound uninvolving.

The source is not all that great, so if you are going to be doing serious listening, you will not be happy. I love XM, but I only use it away from my main system. (work & car)

 

[Welly Wu]

Sirius has proposed to the FCC a partial buyout of XM that is awaiting conditional approval. It will most likely be rejected. However, if it is accepted, then there will be unanswered questions about the hardware compatibility of either Sirius or XM tuners and future ones.

I read that the reason why Sirius is even considering this is because the satellite radio industry is losing customers due to poor customer service, poor audio fidelity, and a homogenization of music streams.

 

[audiomagnate]

This is a headphone forum, right?

XM in the car = OK
XM in your head = BLECCHH!!

 

[Lowfront]

Quote:

Originally Posted by Welly Wu /img/forum/go_quote.gif Sirius has proposed to the FCC a partial buyout of XM that is awaiting conditional approval. It will most likely be rejected. However, if it is accepted, then there will be unanswered questions about the hardware compatibility of either Sirius or XM tuners and future ones. I read that the reason why Sirius is even considering this is because the satellite radio industry is losing customers due to poor customer service, poor audio fidelity, and a homogenization of music streams.

There is no buy out. Its a merge of the companies completely 50/50.

Hardware will be completely compatible with each other. Your hardware will work regardless if and when this happens.

This is not about anything but the fact that these 2 companies are not profitable. They spend all there money competing with one another. If this doesn't go through most likely one will declare bankruptcy.

 

[zotjen]

Quote:

This is not about anything but the fact that these 2 companies are not profitable. They spend all there money competing with one another. If this doesn't go through most likely one will declare bankruptcy.

And it will most likely be Sirius. They've been in bad financial shape for a long time. When they signed Howard Stern, a lot of analysts thought they were nuts offering him so much money considering how unprofitable they had been.

http://articles.moneycentral.msn.com...illDoomed.aspx

 

[blessingx]

Well it would be merger of equals, though Sirius is paying more for the merger and their CEO would have the top slot if it went through.

They had an interesting program on Sirius yesterday with Martine Rothblatt - inventor of micro satellite dishes thus allowing current auto anntenni, talking about how the broadcast range was not used. Supposedly Sirius invented the market, but they were force to split the available bandwidth in half to provide space for a single competitor, thus XM was born. XM started later (so better compression techniques), and got their satellites up quicker. Basically it was saying the initial proposal was for the bandwidth range to send better audio, video, etc. Martine is quite interesting. Besides being a lawyer and scientist, inventing this technology and several autotracking others used in trucking, etc., started a biolab to cure his daughters illness, worked on the Human Genome Project, and add a little spice, he's now a she (below: center).

EDIT: And the subscriber base jump (increasing dramatically over XM though XM still have more listeners) because of the "Stern-effect" has many analysis's saying that was the best bang for buck deal either service did. They're both spending a lot of money (XM is getting closer to the black than Sirius), but Stern is just the poster child for commentary on expenses.