I'm not sure if someone responded to this in the past 5 pages, but Ill say it anyways. You mentioned "My H/U output voltage was 4V, should I set the amp to 2V?" The answer would be NOOOOOO!!!!! Haha. Think of it as working backwards.
If you headunit sends a 1V signal, you have to crank the gain on the amp because it is receiving such a weak signal. Now if you headunit sends 6V, it sends a very strong signal so the gain can be set low, BUT the amp WILL still achieve its full power. Basically, the gain knob kinda "sets the bar" as to WHEN your amp will put out full power, not HOW MUCH power.
That's why 0.2V is on the right side of the gain knob, and higher values (aka like 6V) is actually on the left (turning the knob down).
If you're h/u does 4V pre-outs and you set your gain to 2V, your not setting it at 1/2, you actually setting the gain TWICE as high as it should be so that your amp will be putting out its maximum possible power around half volume on your headunit. Any more past that on the headunit and your amp begins sending a clipped signal to your subs and POOF!.
If you've got any other questions, feel free to ask, I'd be happy to walk you through setting your gains. Hey... we've all gotta learn by ****ing up at some point. I fried my very first pair of eGay subs this way (probably a good thing now that I look at it //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif) but trial and error would **** *** if you burnt up those nice DD's, I'd feel just as bad as you would lol. Anyways, good luck //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif
