archos

ok im new so if this has been asked 100k times im sorry in advance. i would like some advice on how would i set my gains with the dd1 if i use the stock headunit in my 2010 speed 3 and run it through a 3sixty.2 or .3. would i check it before it goes into the .2 to find max voulme, then check it at the amps after the .2? or would i check it only after the .2? i watched the videos on you tube and dident see anything relating to the subject. ill keep searching but was thinking someone got experance in this.