This contraption randomly spawned out of an Idea I had while staring at a broken guitar amp my friend gave me. I stuffed a new speaker, a power supply, and a Sony Xplod head unit into the carcass of the dead amp. This is what I came up with. BTW sorry for a few photo repeats. I took them at odd intervals(as you can see by the change of background).
This unit still functions as a guitar amplifier if you plug into the auxilary input on the rear. There is just no distortion or overdrive feature. I use a 1/4 inch to mono phono plug cable I bought at radioshack for ~$6. I have uploaded some photos of how I set it up....
Step 1: Gather Supplies(Or maybe you already have it?)
As you can tell this was kind of thrown together with random stuff I had lying around, so the cost in my case was free. However, depending on the type of head-unit and functionality you want the price for the individual can change. I just recommend going down to a pawn shop and buying the cheapest one they have. Also if a buddy has one lying around gathering dust, ask him if he'll part with it.
Anyway back to business....
What I used:
Old guitar Amp (the one I used had the circuitry blown)
Speakers: Visonik 6.5 in V654 Rev.02 4 way (100W RMS, 200W max)
(Bought at Big Lots a while back for $22.00)
The original Speaker that came with the amp.
A set of speaker terminals I bought from radioshack.
Wire (I prefer the 2 conductor from radioshack)
Powerbrick 12V (You can probably get away with 11 -15 volts, but you need at least 3 amps)
Buick Logo cut off my cars grill (Logo of your choice, or the original off the amp)