XM now sounds worse

I've recently noticed that when listening to XM Radio, the sound on XM Classics and some other stations is thin, distorted slightly on the high end. I think that while the sound has'nt always been great, it used to sound better than this. I can't figure if it's my system or XM has lowered sound quality by adding more stations.

My setup is kinda strange: The Polk XM Tuner is hooked to a Ramsey FM100 FM Transmitter to brodcast (thru my house only) to my various tuners. Now I do know that this is an 'extra processing step' - but this USED to sound great. Could Lightning possibly mess up the sound in the Polk Tuner without totally frying it? It does'nt make any sense because it used to sound good. I have several different systems in my home, and receiving XM in this manner NOW sounds bad in All my various systems, whereas it used to sound good. So I don't think it is a bad receiving tuner, or the fact I have too much equipment plugged in - like I said it used to sound good, but now....

Any thoughts would be appreciated.
I started getting the XM feed with my DirecTV a couple of months ago, replacing the Music Choice feed. I have it run into my system through the preamp and I would agree that it sounds bad. It is much worse than the Music Choice. I have even tried running the signal through my D/AC and it actually made it sound worse.

I would guess that nothing is wrong with your receiver or gear and much is wrong with the XM signal.
I can't speak to the sound of XM in a home system, but I listen to XM Classics frequently in my car (Audi A8). I have found just the opposite of your experience--that the quality of the transmission has improved significantly in recent years.
XM Still sounds just like it always has. I really is quite good. I have the Polk Audio tuner plugged into my McIntosh MDA1000 DAC with a nice digital cable. Last night I was listening to MX70 (jazz) and I could not beleave how good it sounded.

I would check your transmitter, Also you might try taking the XM tuner and plug it directly into your preamp and check the sound quility. Some hi output wireless devices (modems,phones) can really mess up FM signels.

I don't know if this even remotely helps because it's more a response about XM quality overall, and introduces new variables. I receive XM as part of my DirectTV package and have it enabled through a Marantz processed and powered home theater with B&W CDM-NT speakers, as well as through a Meridian digital home theater system.

I can hear a significant difference between the two that is attibutable to more than just the build quality of the gear. What I've noticed is that on my Marantz rig, the quality is as you described, and I've tried every form of processing, including "direct" and none sound that good to me.

Conversely, on the meridian system, using Trifield processing the sound is quite remarkable. I can push it to high volumes without egregious harm, but can't do so on the other system. When I go into 'direct' mode, it's better than on the Marantz system, but still falls apart musically.

Unscientifically, I attribute this to the meridian's capabilities in both upsampling and bit length conversion as well as general processing capability (trifield is good with all source material, but seems to really forgive bad stuff). Meridian also keeps everything digital, right out to the speakers, so it may be able to deal with the source material better in that domain.

So, my conclusion is that the XM signal is pretty low grade, comparatively speaking. My variable is getting via DirecTV, so who knows if it's being crushed to fit in the allowed bandwidth.
Thanks for the responses.

Do you notice that certian XM Channels sound better than others? For Instance, XM 71('Watercolors'-Contemp. Jazz) has a marked improvement in fidelity over XM 113 - Classical. Maybe its because the recordings on 71 are newer and better recorded?
I would definitely agree with your take on the different channels. I wonder if there is a difference in bandwidth that is allocated to the different channels. Seems like a plausible idea given that the fidelity needed for talk would be less than that needed for higher quality recorded music. Perhaps the classical material has been deemed to be less popular, and therefore not worthy of more bandwidth. I haven't read anything in the audio rags, but will keep an eye out.
I too have the Direct TV and the XM feed is a big step up in sound quality over the Music Choice. All I have is a Phillips reciever that I bought from Direct TV for $35. I do agree that some channels sound much better than others, thankfully 850-Jazz and 852-Beyond Jazz, my primary choices, sound quite good...

Just a guess, maybe (finally) being part of the minority is OK, there might be a study that says pop music lovers do not care about sound quality as much as jazz lovers...
Have my XM tuner plugged into a vintage Marantz 2325. Sounds great.
The only thing that I have noticed with XM is that whether I listen at work thru the Delphi tuner or at home thru DirecTv it is a low output signal. I have to turn the voulme up about another third to match the other inputs.
I have a Polk XM Tuner routed into a Benchmark DAC-1 and have not noticed any difference in sound quality; and listen quite a bit. Completely agree on the difference in sound quality of various XM stations. Jazz, Instrumental & Classical stations are much closer to the digital quality sound advertised than any of the rock, popular, country stations, ect. Interesting comments above on bandwidth allocation to the more popular channels and the requirement of bandwidth for voice versus instrumental; although I always felt that on commerical FM Jazz & Classical stations always sounded lights years ahead of other formats in terms of sound quality, and XM has the same effect.
It's just my opinion, but I think it's all about compression and sample rate of what gets transmitted to the satellite.

There is a huge difference in listening to the exact same recording on CD and then hearing it on either of the satellite services. My opinion is that it's a limitation, (either purposely, or not) of the technology at this stage. I suspect they could make it better, but why, when it's mostly us audio-geeks who even notice the difference.
I also notice a difference in sound quality between different channels. The other thing I notice is in my car when some channels drop out I can switch to a more popular channel and it will not drop out. This may have something to do with bandwidth. I listen to 7 (70's), 70 Real Jazz) , 71 Watercolors) If I listen to the heart (23) it drops out more offten on the road.