You could have a weak battery

The BMW IBS (INtelligent Battery System ) has the ability to turn stuff off when
the battery is at a low state of charge. The other explanation is the first one
the overheating one.
Which sound system of the three available do you have?
No matter what system you have I think it would distort pretty badly at max volume if not way before.

http://www.google.com/url?sa=t&rct=...YR5QNFyu70IsyKRlg&sig2=_9rm-BkaeBBPIzRytI5ThQ

I'm not so sure that the battery being at low charge would be the cause. If I've been driving for 20+min, the battery should have recharged what was depleted when starting the vehicle. However, this is just an assumption -- so I'm not going to "blow off" the idea.

I'm not sure what the three sound systems are...if I told you that mine is the Logic 7, would that be the right answer?

What do you mean by "distort"?

Did you read the link at all?

Did you read the link at all?
You don't know what distort means?
Did this always happen or is it a recent occurrence?

I gave the link a view, but I'm on my phone, so I didn't look at it in too much detail. I figured you were citing your sources on your comment about what the battery can do.

I do know what distort means...but I am confused because it sounds optimal at max volume.
I used to be a dedicated guitarist. We put thousands of dollars to get our tone the way we want because our ears are picky...but this sound system has my approval.

It always happened.

This amp goes to 11

This amp goes to 11
But it doesn't sound very good there or last for very long .
I also play guitar and have a couple of Mesa Boogies but would never run them at
11 .
Think tinnitus.
It may not be the battery but it is a thing to check , particularly if the battery is 4 or more years old and if the car doesn't see much highway mileage or is sitting around for a long time.
If you run anything at full tilt it puts a strain on it. This may be an effect you desire from your guitar amp at the price of replacing speakers and or tubes but its not something
you necessarily want to do with something you do want to break or you want to last awhile.
If it doesn't cur out at lower volumes and you still want louder I think you need to modify
your stereo system with a larger amp and better speakers.

http://www.e90post.com/forums/forumdisplay.php?f=27

I don't know if having all of your EQ controls "maxed out" is causing your problem, but its a really bad idea from a sound quality standpoint. Equalizers are designed to correct "inequalities" in your systems frequency response (hence the name). Try reseting all of the controls to 0 (neutral), and use your ears to determine which frequencies are too loud or too soft. Just make small adjustments that make the system sound smoother and more accurate. You should not have to have any of the controls maxed out.

Check out my post in this thread... It's got screen shots of my settings, which sound awesome.

http://www.bimmerfest.com/forums/showthread.php?t=533659

Do you also get a BMW Assist error? I had this problem intermittently a few years back (all audio functions would randomly stop working, with an Assist error message showing up on the dash). Dealer fixed on the second try - I believe they updated the software for the bluetooth module, based on a SIB for the 5 series. Good luck.

I do not get an error message at all, no.

does it happen if you keep the volume at mid level? the amp may be overheating

Do a search on here for equalizer settings.....it must sound terrible maxed out and at full volume.