Hey how can i turn a speaker wire input (from my rear deck speaker) into an RCA input. I know its not the best idea in terms of SQ but i need RCA's so i can add a bass cube or some kind of EQ between the input and my amp to get a speaker level adjustment from inside my cabin.

I had one in my car, but it sounded like poo, so I ended up tapping into the line outs on the back of the head unit. But that is what you would need.