Depends, the very latests onesare only if you ordered XM. In other words it's a Cellular/GPS/XM antenna. It's true for many GM's, not sure what's up with the latest H3's.

Before that, XM and OnStarhad separate antennas.

If you have XM and OnStar with only one antenna on the roof, it's the latest one described above.

 

Just to add to the mix, I had the SIRGM1 installed about 8 months ago to my '07 H3 - They ran a Sirius antenna up the passenger windshield column and this is what the factory NAV System/ Radio looks like (it still displays "XM" but shows that names of the Sirius channels):



[IMG]local://upfiles/1314/9A5A8F23ED8F430E96D284563B1A07D0.jpg[/IMG]

 

Drove from Rochester, Ny to Ohio and back. Had a few issues with the radio cutting out, couple times while on an island and a few times while driving in downtown Cleveland. Other than that it seems pretty good.

 

Other than the reception, how would you rate the sound quality?

 

I would say very good. To me I seem to get better reception with Sirius, Xm cut out on me more.

 

Anyone else notice this XM change during last weekend? I think the sound is cleaner, not so much fuller/richer.

This is from XM's website:

XM STATEMENT REGARDING SOUND QUALITY
UPGRADE FOR XM MUSIC CHANNELS
• XM will implement a sound upgrade on August 5th.
• In partnership with Neural Audio, XM has implemented a new upgraded audio processor for its music channels, resulting in a fuller and richer sound across the more than 70 XM music channels.
• This upgrade has been in development for over a year.
• Listeners may need to make adjustments to their audio settings (Bass and Treble) for their individual radios to fully experience these sound enhancements.

SOUND QUALITY UPGRADE: Q & A
Why does my XM radio sound different?
XM and partner Neural Audio implemented a new upgraded audio processor for its music channels, resulting in improved sound quality. You may have to adjust your audio settings (Bass and Treble) on your XM radio to meet your own preferences. Once you do so, you should experience improved sound.

Why did XM implement this change?
We’re always striving to enhance quality of our sound. Over the year, XM has been working closely with the sound experts at Neural Audio to implement this sound upgrade. Our extensive testing indicates this upgraded package will deliver an enhanced audio experience.

How is this better or different?
This upgrade should make your XM music channels sound even better by delivering a fuller, richer music experience.

Does XM have plans to upgrade the sound of its news, sports or talk channels?
XM is always striving to enhance our sound quality and we will continue to upgrade our sound in the future. The timing of those upgrades is to be determined at a later date.

Is this just more of XM compressing music channels to gain bandwidth?
These enhancements are purely fidelity improvements, no bandwidth efficiencies were derived as a result of these improvements.

 

XM ans Sirius did merge and according to the website within a year you will be able to receive any of the channels on your XM or Sirius radio.

http://www.xmradio.com/merger/news.xmc