XM Radio Sound Processing

Rob.melone · 01-11-2005, 09:41 AM

I continue to be amazed at the sound quality of XM radio at home. Music recorded in the 60's sounds like I have never heard it before. Contemporary jazz, country and classical music is even better. The sound is full, clear and crisp with unprecedented stereo separation and imagery. Has there been any speculation that XM may be enhancing the sound before it is transmitted? I say this because the sound quality of my CD’s seem to rival that of XM. Since both are digital, how can this be if the sound at XM is not being processed? I also notice that the sound effects that some disc jockeys use also sound processed. This is in no way a criticism of XM. I am just interested in what is going on. Rob

Michael St. Clair · 01-11-2005, 11:10 AM

I find both XM and Sirius to be substantially lacking in sound quality compared to CD, or even 192kbps VBR MP3.

'Processed' is a dirty word to many of us.

dpippel · 01-11-2005, 02:17 PM

I'm with Michael. In my home system the audio quality of XM was generally so bad that I returned my SkyFi2 and Home Kit and canceled my XM subscription. Couldn't live with it. I expected satellite radio to be at least equal to a quality FM analog broadcast, but I got fairly bad, compressed MP3 quality instead. It's a shame because I was really impressed with XM's programming and would have stuck around if it had sounded better.

Rob.melone · 01-11-2005, 03:49 PM

I can’t understand how there could be such an incongruity with the sound quality of XM Radio in the home. Especially, when considering that those who have responded to my thread, indicating that the sound quality was poor, are experienced audiophiles.

Ronald Epstein · 01-11-2005, 04:57 PM

Well, I'll be the next to admit that I read
Rob's testimonial with much confusion.

I don't know how anyone can say that satellite
radio rivals CD quality. It doesn't.

Audiophiles will instantly notice the inferior
audio quality of satellite radio to CD. Most
others will probably not unless you play both
side-by-side.

Of course, how one hears audio is purely subjective
and it is usually based on what type of equipment
you are pumping it through.

**HTF Ads**

Bob_L · 01-11-2005, 06:30 PM

Aside from the cost of entry, I think this is the greatest problem with satellite radio. The sound quality just isn't as good as it should be or could be.

In an effort to maximize the variety of programming, they've minimized the available bandwidth which, neccessarily, limits the potential quality of the audio.

Satellite radio seems to have done fine delivering the programming part of their marketing message. However, I think to get to the next level, they need to add a performance quality component to that marketing message. And then deliver improved sound.

XM is by no means "digital-quality sound remarkably close to Compact Disc" as is claimed on the XM Radio site. As such, it may be fine for in-car listening, but it will never, NEVER gain a foothold among home listeners (even non-audiophile listeners) at its current audio resolution. They need to use their bandwidth more efficiently (or get more bandwidth) and they need to improve their codec.

I have XM playing in my home office most of the time on a smallish stereo system with bookshelf speakers. After connecting it to my large home theater system once, I put it back in the office. When I want to listen to music seriously on the "big" system, I use CD, SACD or even MP3, NOT XM. I wish I felt differently.

Detractors shouldn't take this comment as another anti-satellite radio argument. I've been a satisfied XM subscriber for over two years. (Man, hard to believe it's been that long!) I'm impressed with the depth of their play lists, particularly in the relatively esoteric areas of jazz and classical music, and am grateful for some of the more "eccentric" offerings (at least compared to broadcast radio) like radio theater, world music, comedy and the weird Christmas music channel.
At present, XM Radio is very good. I just want it to be GREAT.

Ronald Epstein · 01-12-2005, 08:02 AM

Bob,

I agree with your post 100%

No argument.

I fear that satellite radio is going to go the
way of just about every other medium that was
supposed to deliver superior quality over the old.

For example....

Cable, Satellite TV and DVD were all innovations
accepted by early adopters for their superior picture
and audio quality.

Once these became mainstream, picture and audio
were compromised thanks to the squeezing of the
available bandwidth in order to provide more
entertainment.

The fact of the matter seems to be that the
general public seems to be more accepting of
having more entertainment available to them
at the cost of reducing picture/audio quality.

Rob.melone · 01-12-2005, 09:15 AM

Well guys, I am compelled to defend the fact that I know good sound when I hear it, but I won't. Suffice it to say that XM Radio at my house on my system is very enjoyable with all the attributes that are pleasing to me. They are: fullness with a solid low end, clarity, crispness and imagery. The whole purpose of my thread was to engage speculation as to whether XM is or is not using software to enhance the sound. My guess is they are.

Here is my system:
SKYfi2 (Laser Disc in, gain set at full, 6 bars of satellite antenna reception)
Sony ES (w/equalization at both ends of the spectrum)
Magnepan (positioned on long wall)
S-M size room, carpeted, fabric furniture

Anyone interested in a demo, let me know. Thanks. Rob

Ronald Epstein · 01-12-2005, 10:41 AM

Rob,

Listen, everyone hears audio differently.

We could put a dozen average people in a
room with your equipment and I would estimate
that someone would agree with your opinion on
the sound quality of XM radio.

Bob_L · 01-12-2005, 10:51 AM

Rob:

My apology. I didn't mean ANY of my post to reflect on your satisfaction with the XM sound. Like you, I'm quite happy with XM.

Actually, on the XM site, they do specifically mention that they use some kind of processing -- that they call "Neural Audio optimization" -- in addition to the compression. My guess is that this is some kind of psycho-acoustical treatment that modifies the sound to conform most closely to the response curve of human hearing and, therefore, create a more satisfying balance of frequencies.

In addition, they DO some kind of imaging processing on the sound as well.

You can read about it all here:

http://www.xmradio.com/corporate_inf...cts_sound.html

Rob.melone · 01-12-2005, 11:48 AM

Thanks for the support Ron and Bob and thanks for the info on "Neural Audio optimization." This makes complete sense and is no doubt what I am hearing. Perhaps one day this technology will be available to consumers. If nothing else, I hope those who read this post and are not happy with the sound of XM Radio in the home will do some experimenting with their set-up. It just might make all the difference. Cheers! Rob