Old speakers with some life left in them can be hooked up to a computer for kicking stereo sound. The problem is, computers are not equipped with an amplifier sufficiently powerful to drive a pair of stereo speakers at any volume, so an amplifier must be used to make the connection work. A Y-adapter for audio applications also will be needed to convert the RCA jacks from the amplifier into a mini-plug connection for the computer. The entire setup should take less than 10 minutes.
Attach the speakers to the amplifier with speaker wire, using the red wire to connect to the positive terminal and the other wire to connect with the black terminal. Lift the spring-loaded clips on the back of each speaker and the amp to reveal holes for inserting the wires.
Connect a set of RCA-type audio cables to a set of free audio input jacks on the back of the amp. Make a note of which set of jacks (such as Aux, or Auxiliary) is being used for the connection. The red plug on the cable attaches to the right audio jack. The white plug attaches to the left.
Insert the plugs on the other end of the cable into the RCA jacks of the Y-adapter.
Connect the other end of the Y-adapter to the computer's Audio OUT jack.
Plug in and turn on the equipment; then set the amplifier selector knob on the front of the component to AUX or whichever jack is in use.
Play back an audio source on the computer and adjust the amplifier volume to the desired level for listening with the old stereo speakers.
Things You'll Need
RCA audio cables
Y-adapter with RCA jacks on one end and 3.5mm mini-plug on the other
A home theater Surround Sound system can be connected to a computer in the same manner by plugging standard RCA cables into a Y-adapter for the computer's audio output and attaching the cables on the other end to the input jacks on an AV receiver.
Connect the speakers and amplifier to the computer before plugging the equipment into the electricity.