Thanks @motolatte, I just checked and my sub's gain was maxed out. Turned it down to 30-40 % and now I can fine tune with the knob. The premium sound is still not great but it will do for now.+1 on this... Drove off with my new Grenadier without trying the stereo first, spent an hour of the ride home trying to mess around with the fader and a custom EQ only to come home and find this post. PSA to dealers: tune these sound systems prior to delivery... I thought I was going to be upgrading stereo as well, and was so disappointed in with what I thought was "Premium Sound" LOL. Gain knob was maxed out on mine... very easy to remove the sub and dial it in same way with tiny screwdriver