My new Head Unit has front, rear, and subwoofer outputs. I am installing an EQ with one set of inputs, and 3 outputs (front, rear, subwoofer) . Then all this is going to an amp. I wont be using a subwoofer, just the four speakers.

If I only have one input on the EQ, which output on the head unit do I run the patch cables from? front, rear, does it matter? will the sound coming through just one set of inputs no longer be stereo? in the end sound will come out of all 4 speakers because of the two rca cables going to the amp, but will it be "correct" musically, I guess is the right way to phrase it- you know when you hear a guitar in one side of the vehicle or a cymbal on the other side of the vehicle.

I am thinking I will lose the ability to control the fade on the head unit, and only be able to use the fade on the EQ. Is this true?

 

Use either front or rear, although some decks have features like pioneer for different controls - in this case I'd use the fronts. The only fader control you will have is through your EQ, the balance will be controlled through your deck/and or EQ. Otherwise you won't have any trouble with only mono audio, or guiter in the wrong place.