subwoofer wire question

[SameSuspect]

I have a spare subwoofer in my room which doesnt get used, and a subwoofer out port on my technics hifi that also doesnt get used because it uses the "RCA" format but the wire on the subwoofer uses a standard connection that clips in to a dvd player. is their a converter or a way of using the sub on the hifi? thanx

 

[SameSuspect]

im not sure what model it is as it was a part of a cheap dvd system which broke a whole back, it has no stickers on it. their are no buttons, switches on it, just the connection port. so i dont think it has an amp.