hey i had some company install my subs and amp and they hit like ****. i have an aftermarket head unit and rca run from the deck to the amp then the amp has 2 wires runing to the subs. this is right but i want more bass and my setup should give more because my friend has almost the same set up and he kills me! i looked up this diagram is it good? and do i splice into the rear speakers and take + and - and make them into one wire for the left or just the + wire? help...

here

 

If you have a aftermarket head unit use a true rca cable there should be ports in the back of the head unit and they will be labeled maybe even labeled sub out. Make sure that the amp is turned on low pass filter. The way I have mine hooked up is take the speaker wire from each sub and put in the speaker out ports bridged which means put + in the port marked + in left channel and - wire in the - port of the right channel if amp is two channel or sub amp only. If it is 4 channel amp run left speaker wire into 1 and 2 channels bridged and right speaker wire in 3 and 4 channels bridged and you will have to get Y adapted for rca cables to have 4 plugs instead of 2 or just run 2 rca's back to amp from head unit if you have enought rca out's. Most head units come with at least 2 rca outs sometimes 3 or more.

Try that and if you have any questions PM me.

 

what year? did it have a premium sound or mach system in it? I am willing to bet it did and they did not bypass the factory amps. The factory amps start to sound distorted and bad at a much lower volume then almost any aftermarket equpment, making the system sound bad. More then likely the gain on the amp is turned up all the way to try and get the amp to keep up and this can cause damage to the amp.

It is easy to bypass the factory amps in fox bodies and at least up through the mid 90's as far as I am aware, I just have not had my hands on too many newer models since. Page 2 of my signature shows how I bypassed/integrated into the system but it does not have to be that hard.

It would also be very helpfull if you could give a list of what is in your car now since I/we cannot really give good safe advise until we know what is in your car.