Is this the same procedure as subs? Can my speakers be hooked to the head unit as well as the amp? Am I going to see a big difference?

 

If your speakers are able to stand more power being put to them, then yes, you WILL see a difference!! The hu starts to distort the speakers after you get above its rms line, even though the speakers can handle more. When you hook the speakers up to an amp, you're amplifying the power they're getting, therefore, you can turn the volume up louder w/o hearing distortion.

To hook them up... you want to run RCA's from the battery (make sure it's fused) into the back of the hu. Use the preouts on your hu (rear) instead of the rear speaker wires (make sure you either butt connector the ends, or use electrical tape, so they don't short out your audio system).

If you have your subs hooked up to your rear out (if you don't have a non-fading out) what you can do is get Y-connectors (walmart sells them for 4.50 for two.) Hook the left and the left into one and then the right and the right into the other. Use your amp's crossover to determine what hz get to go thru (lower freq for the subs, mids/high for the 6x9's) The only downside about this is, if you would fade to the rear, not only will your 6x9's go up, but your subs also will.

Hope this helps, it's kinda hard to explain. If you need some help, do a search at the sound domain forums - there's plenty of topics like this over there. Link is in my sig...