I have a 8-month-old MR M3 and the other night I was reversing and my jacket sleeve caught the volume wheel and cranked the stereo all the way up (much to the delight of my wife and kids!) Since then, the stereo doesn't sound the same. The bass seems a little muffled when it used to sound deep. I don't hear any crackling or popping, just not as much 'performance' as before. Am I imagining this? On a similar note, would the stereo be covered under warranty? Thanks