So, I recently installed the Z150 in my Toyota Venza and used the SXV200V1 for Satellite Radio.  I Installed the included antenna on the roof of the Venza, right behind the stock antenna.

The radio sounds very good.  Reception is normally very strong -- I rarely even lose signal going under overpasses.

However, I occasionally lose sound for a brief second, and I can't decide why.  Most times, the signal strength is still high, so I don't think that is it.  When I use the "rewind" feature, sometimes the glitch is present on playback, sometimes not.  Changing the station always remedies, so it's not an amplifier or interface issue with the JBL. 

If I switch to another present channel and use the "rewind," sometimes the glitch is there and sometimes not.

Very strange.  It's only a brief second, sometimes two, but I rarely go more than two hours of driving without it occurring.  At first, I thought it was signal strength, then perhaps a problem with the individual channel, maybe the tuner, maybe the radio processor.  Who knows.

Anyone experience anything similar? 

EDIT:  Now that I think about it, before I got the XM hooked up, this "glitch" occurred once while listening to FM.  I wonder if the problem is the head unit itself.  Question will be, is this a processing issue that would occur no matter what or indicative of a problem?

Does a grey coloured box show up with the letters "ATT" when you loose volume?  I have experienced this after anywhere form 40 mins to 60 mins of driving.  I haven't done any troubleshooting as it hasn't happened in a while and my travels are typically less than 40 mins.  From what I recall reading it had something to do with sound Attenuation??  Where something is wanting to lower or mute the audio... If it ever happens again for me or becomes a nagging problem I will look into further.

I've never experienced this issue with my radio.

I have not experienced the loss of sound (other than when I go into a garage or tunnel or during exceptional weather) with my XM tuner.

Whenever I lose sound due to loss of signal, that gap in coverage is always in the "rewind" playback, thats the nature of the Digital Audio Recording (DAR), the same way a DVR at home records signal loss on your cable/satellite TV.

My longest non stop drive so far has been around 3.5 hours and I never experienced a sound glitch that wasnt reception based. If you are experiencing it with perfect reception, your SXV200V1 is probably to blame, not the Z150, especially if the glitch was recorded and repeatable. The SXV200V1 does the DAR function as well as the XM tuning, its not a function of the head unit.

Since the SXV200V1 is actually recording 6 channels at once (your 6 favorites currently on your screen) see if the glitch is in all 6 channels rewind buffer at the same point of time. If so, and you truly had perfect signal, then the SXV200V1 is definitely to blame.

Note that you do a memory clear if you switch from one set of 6 favorites to another 6 sets of favorites (you have 3 of these 6 channel preset modes available from the Z150, but the SXV200V1 can only handle 1 at a time).

The only time I see "ATT" pop up is if I have volume attenuation turned on for cell phones/map guidance. You can chose to attenuate or to mute when one of those two actions initiate... Attenuation is generated from the z150, not the XM tuner.

If you are having HDFM digital problems, those functions are a part of the Z150 built in tuner... if you are having the exact problem in FM that you are having in XM then you've got me baffled... in my experience HDFM is far more prone to signal loss than XM. Data pops and loss of audio are so common that on HDFM in my region that I just use XM exclusively.

Hope this helps.

Turns out, the interface was not compatible with my make/year vehicle.  Sounded great, but it occasionally lost sound for a few seconds.  I switched to a new interface, and it worked fine.