How do I connect a subwoofer to a 30 yr old receiver?

Question

How do I connect a subwoofer to a 30 yr old receiver?

Answer 1

Use a sub crossover.

Answer 2

Assuming you mean there is no dedicated LFE output, I would suggest getting a subwoofer that provides a connection for speaker inputs from the receiver, splits off the lows to the subwoofer and allows the mid/highs to output to the front speakers via speaker connections.

Basically, you cut the wires to the front left and right speakers, attach all 4 cut ends to subwoofer and yoiu are done. In practice, you might need to add a bit of length to the input or output wires.

See the link for a picture and explanation