Okay I just had the Valor DTS 660WT headunit installed in my 98 Mercedes CLK with factory Bose speakers. For those who don't know...Valor is a mobile multimedia system (includes: in dash DVD player, touch screen, tv tuner, ipod control, bluetooth control, etc). I know absolutely nothing about car audio systems and my installers were not the most knowledgeable people in the world. I am trying to figure out how what i should set my audio signal processing (straight from the manual...lol) options to. The menu lists the following: bass frequency, treble frequency, sub filter, sub phase, bass q factor, fm/am gain, dvd gain, tv gain, bluetooth gain, sat gain, ipod gain, nav gain, sd card gain and aux in gain. All of these can be set to different levels but I am TERRIFIED that if I set the level wrong I will blow my speakers out. I believe my car has a built in amp in the truck or something too. Do you guys have any suggestions on the best settings. Remember....I know nothing about audio except bass, treble, fade, and balance....lol....