What about the PC?
I wouldn't use the ignition switch itself. If something goes wrong, you could damage the ignition system o the vehicle, and that would be bad. Look for another circuit.Would I just run a wire from the ign switch wire from the head unit to the amp?
Throw a two-position switch on your remote line. That will turn it on & off.The amp doesnt need to be on all the time, so it would be convenient to wire a hard switch to turn it off/on when needed so could I run it from any power cable and splice a switch in there?
That's one I don't know how to answer.There are a total of 6 speakers that need to be hooked up; 4 in the very back, and 2 under the middle seats. The back 4 are pretty close to each other so I figured I would just wire the rear speakers as pairs, so would I need a 4 channel amp?
A four channel amp will have two sets of RCA inputs.How many rca inputs are on 4 channel amps? I think most dvd players connected via rca (red, white, yellow) only out put in 2 channel sound right? So perhaps I would need to run component cables (for 5.1ish sound)? Are there front and rear rca inputs on 4 channel amps? I have only worked with mono and 2 channel amps.
How to get that? My suggestion is an equalizer (see below).
Yes.The plan is to have no head unit connected to the amp. Basically just the audio from the dvd player output to the amp output to the speakers. I can do this right?
Good question.How would I control volume though? The dvd player doesnt have its own volume control.
I'd look into an equalizer that has its own volume knob.
In addition to having a volume knob, you can run a single pair of RCA's (simple stereo) into the EQ and it will separate the channels into Front & Rear & Sub.
You can also adjust the sound parameters to your liking.
Yes, it's more money that you'll spend, but it will make this a lot easier to control, as well as answer some of your questions about wiring to the amps.