Originally Posted by robo171
So here's the deal. I have an old receiver/amplifier. Its older, so the only outputs (to the speakers) are standard +/- speaker wire. I would like to hook up a powered subwoofer to it (it has its own power cable). The subwoofer takes a 3.5mm jack as its input, but the receiver only has outputs for the +/- wire. How can I hook these up together?
The problem with most 3.5mm jacks is that they are designed to use 20-24 AWG cable, with some you can get away with 18 AWG. If the +/- output you are refering is for the sub only, just get a mono 3.5 mm jack that you can buy at any electronics store, the most expensive one is probably no more than $4.00. Solder the + cable to the + in the jack (center - plug), and the - solders to the - in the jack (side - body). Radio Shack sells one that uses screws and there is no need to solder, just be careful that the + and - cables are touching. You can also do this using mic cable. Sounds more complicated than what it really is. These cables are usually thin (24 AWG), so doing your own 18 AWG is a good alternative.
A simpler option, buy a 3.5 mm jack x 3.5 mm jack cable, cut one end, and insert the + lead and - lead in the receiver, and the end with the 3.5 mm jack in the sub.