BCAE1.com
Hands down the most thorough information site for car audio and everything that it encompasses. Theory, equations, application of principles etc.
I got one, I was actually looking up the specs and this post came up on google. I am hooking it up in my ride to two Image Dynamics ID12's. I am down to off it to you, I'll throw it on the oscilloscope too to make sure it's 100% good.