Im having hard troubles setting my Gain on my Amp. I have a 3000 watt amp and having my subs on a 2ohm load and i know thats all the information you need to set the gain using the formula with sqrt which i forgot :/ but i was trying to set up my gain, i watched a few youtube videos and i first turned down all the gain, subsonic, etc besides the lowpass which i put up all the way, so i unplugged my speaker wires and turned my radio all the way up and put the volt meter across the speakers, i have no reading on the voltemeter and i have the voltmeter to read ac, and i have song playing, so what am i doing wrong?