This has happened a bunch of times, at first i thought it was only when i had the music loud for long periods of time, but now i'm starting to realize that when i really push it (over 100mph) the bass goes out shortly after. one time all sound went out. the dealer wasn't able to find anything wrong at all. i usually have to shut the car off for a few min and then try again. I have a cab. has this happened to anyone else?