Yes, something like a JL Audio Cleansweep or Rockford Fosgate 3Sixty.1 simply converts the signal coming from your factory head unit into something your amplifiers can use. It also will correct any funky equalization that your car's head unit induces. A cheaper alternative, which will still sound alright, is to use a line-out converter. It does the same thing as a Cleansweep, except that it doesn't correct factory equalization. What you could do is pair a line out converter with a ~9-band equalizer for optimum sound adjustment, and set the gain on your amps higher to where you reach maximum volume before your head unit adjusts the sound.

A carputer would be an excellent choice. I've never had the chance to install one, but I love their flexibility and features.

 

jman,

Thanks for the info! I wasn't really sure what could be done with the stock headunit.

A carputer would be nice. I'd try to get a nice soundcard that would work, something that has it's own front, rear and sub channels. Use software to equalize and cross over the channels so only what I want is going to each channel. Then amplify. It could be VERY versatile.