What voltage required to power a sony subwoofer (by 3 users)

Hi there,

I've just got an old sony sub which was going to be thrown out. There's one RCA input which appears to take line level, and also another cable, which I'm guessing is for power. It originally came with another hi-fi system, which obviously had the correct voltage output to power the sub. It's a very small white connection, on a thin 2 core cable. I'm guessing it probably only requires a low voltage to power it, but I don't know what voltage that would be, and if it would be AC or DC. I'm guessing DC?

Anyway, I can't find a free manual to download anywhere, so I thought I'd ask if anyone knows the power input required to run a sony ss-WG990 subwoofer.