so im gonna add my 3 12''s to the max,, but i want to keep the stock head. i realize there is not gonna be any RCA outputs on the back of the stock (non-bose) head. i read on the forums somewhere that the lineout converter makes the subs sound like sheeeit... is there something else? i dont know wtf ur supposed to do w/o RCA cables...

 

A line convertor isn't going to make it sound like sheit. The overall sound of your system is going to improve with the addition of your subs. However with that much bass your deffinitly going to be over powering the highs. So I suggest amplifying the high end down the road. If you still want to use the stock H/U to deter criminals from thinking you got a system then do this.

Run the single set of RCA's from the line out convertor to a 3way dash mount electronic crossover. That way the crossover is suppling the voltage to the amplifiers instead of just the line convertor. Most crossovers are rated at 3volts or higher for each set of outputs. I recommend a Audiocontrol crossover or better. http://www.audiocontrol.com/images/Three1.gif That way you can run 3 dets of RCA's to your amp's (front, rear & sub)
When I was running this exact same set up I mounted the crossover inside the flip down pocket underneath the stock radio. So when I wasn't in the car I could close the pocket & not have to worry about theives.

So you can read about there products.
http://www.audiocontrol.com/caraudio.htm