What's up all,  Here's my situation that's kind of annoying.  Randomly as Im driving listening to my system which consists of: Head.: Pioneer 7800MP Front: CDT HD-62/DRT26s/EX-560i F.Amp: Arc Audio 2100 CXL  Subw.: Ascendant Audio 10" Assassin S.Amp: US Amps XT-800.2 My highs will just cutout.  However, they'll come back on if I turn the volume up.  The arc 2100 was bought used from ebay, and im thinking that's my culprit.  Not too sure. What do you think?