Can I use speaker wire as RCA?

abosloutely not! you will definetly damage your amp and or cd player. if your deck does not have rca outputs, there is a converter you can buy at any car audio shop, or even walmart for a few bucks. it converts your speaker wire to an rca output. you plug in a set of your speaker wires from your deck, then on the other side is an rca output where you would run a pair of rcas from there to the input on your amp. then wire your sub to the amp. thats all...fairly simple

It should work. But then you would be using some of the speaker outputs from your deck. If you still want to try it, get a potentiometer, (variable resistor) for a few bucks and stick it into the wire, (only one conductor needs it) Then use it to adjust how much voltage goes to the amp.

I would get about a 5k potentiometer (pot) from an electronics store. 5k = 5000 ohms. The resistor will go from open, to 5000 ohms resistance, like a valve for the power going through the wire. Simple.

Allow more power to the amp until you get distortion, or it is as loud as you want. If you have a multimeter and know the recommended input voltage for your amp (for instance 250mV), then you can adjust the pot till you have it calibrated right.

I used Belkin PureAV Speaker Cable Wire Pin Connectors. These connectors have threaded screws which secure the bare wire so no soldering is needed although the manufacturers do say soldered connections give better sound. I tried soldering and got in a right mess. It's not as easy as people make it look! Have a look for them on eBay.

I have also just notices I have 'High Level Inputs'

Only use that..

yep...you will fry you radio. you can not run an amped signal from you radio to your amp. get the converter.

nope sorry