I'm too cheap to buy a Voltmeter (Hell, I don't even know how much they cost), so I wanted to tune my amp by ear.
I set the gains to zero\off\low\whatever you want to call it, and turned the HU up until it distorted, which was around the 27 range (Alpine 9830). I gave it a little breathing room and put it to 25. I then disconnected all but 1 set of RCAs (the front) and turned it up until it distorted, then I backed it down a tad. I did the same for the rear, and I will do the same for the sub when I get it tomorrow.
Now, considering I have a 75w rms and 40w rms speakers, I was surprised that they both maxed out at the same gain setting on a 50w x4 RMS amp, which wasn't even half way. Did I mess something up, or miss something?