NO! lol its not a volume knob. if you set it too high you get clipping and fuck your subs. just forget about all the other factors we talked about. its nothing you need to worry about at this stage. set your gains CORRECTLY and you will be fine.
Yeah if you max everything out say the gain, bass boost and your HU settings along with the HU volume man, whatever subs you have will not like that at all LOL!