Head unit with NO RCA's only speaker outputs?

The head unit in my vehicle has no RCA outputs only speaker outputs.

Is it possible to amplify the four door speakers using a high level input on a amplifier?

Also is there any way I can run a subwoofer?



Currently I have four components and an active sub running with a high level input and its not sounding very good!

Does this option make sense: An ISO to RCA (4 way) converter, this would then amplify the door speakers but how do I run a convention 12" sub in an sealed box?Head unit with NO RCA's only speaker outputs?
If you are wanting to do it properly you could use an Audio Control part an LC6i. You can see this on this link http://www.raysmith.co.uk/LC6i/

I have used many options and if you want the best solution this is it. This will give you 3 outouts, front, rear and sub, the speaker to RCA leads you get are very poor quality and will most probably bring interference into your system.Head unit with NO RCA's only speaker outputs?
well i have here a alpine speaker to line out level converter so you must be able to buy them