Help? I think my HK amp isn't working right
 

I have a 2011 Cooper S, just brought it home. The only problem is that it doesn't sound like the amp it on. When I adjust the "gong" setting, it seems to click in and the sound gets really full and loud (like it used to sound on my HK system in my 2004 Cooper S), but without that button pushed, it just sounds not so good. Anyone have any ideas, or do I have to take it to the dealer to get it fixed?