Sub Cuts out

Heh, power and ground are 4guage, I have 1 12" Phoenix Gold Titanium Sub. It runs at 4ohm. The deck is a pioneer, i dont think the preamps are more then 2.5, which kinda sucks. I think bigger amps generally require more volage on the imput. But i could be wrong.

nah the inputs should all be the same---- 1996 Chevy S10 ----

1 Lightning Audio S2.600.2 Amp

2 Lightning Audio 12" Subs

1 Lightning Audio 1 Farad Cap

Then what is the purpose of a line driver?

A line driver increases line level voltage to help prevent audible interferrence and increase signal strength when using long cable runs.  In most car audio installations they are actually unnecessary unless the line-level signals from the HU are very poor quality, or the installation requires splitting a signal into multiple amps.  Your amp cannot handle the high voltage from most line drivers, and if your HU outputs 2.5V the input gain should be set to just below 1/2 scale to begin a matching process.

Finaly, some good info. I redid my gains, wiht that info, and i get so much more pound outta my sub. I havnt had any kind of cutout issues at all lately, so im alright, i havnt even got a chance to look at it yet, my garage is cluttered with crap that needs to go away.