Installing a powered subwoofer?

[takza]

I have a tube type powered subwoofer I want to install. Have probably lost the instructions for it.

Has 4 wires...black and red for ground and power. And 2 wires that pickup the signal from the speakers.

So speaker wires are "polarized"? How would I know which of the 2 wires to the sub go to which of the speaker wires.

Will one speaker wire show plus voltage when the radio is on...the other acting as ground?

So what is the easiest place to hook up to the speakers?

With my SR5...I'm pretty sure I removed some rear speakers...can anyone say where these wires normally originate?

I have a good wiring diagram...so I know what colors they should be. Black and Black/White on the right side.

* to answer my own question...turns out the two wires are for the left and right channels and neither are grounds. The speaker wires in back come out of the lower openings with the covers on both sides....found the speaker wires inside. Have both channels hooked up now. We rockin'.