Tape Out as Subwoofer Output?

As Narrod said, if your subwoofer has 'high-level' inputs in addition to the 'line-level' inputs you can run a second pair of speaker cables from the speaker terminals on your amp to the high-level inputs on your subwoofer.

That can be done either by running cables from the 'B' speaker outputs on the amp if you have them, or by running two sets of speaker cables from a single set of speaker terminals, one set to your main speakers and one to the subwoofer. If the second option is all that's available to you, attach the second set of speaker cables either by using banana connectors into the ends of five-way terminals or by doubling up the spade or bare wire connections, or a combination of any of those.

The second set of speaker cables can be a smaller gauge than your main cables, it's just carrying frequency and amplitude information that the subwoofer amp will work with.

Thank you kindly for the clear explanation. I had meditated that move previously but imagined Chinese fireworks demolishing my listening room.

Hey guys, I thought I would add something here.

I have a 1959 vintage Sherwood S-5000 el84 stereo based tube integrated amplifier.

It has tape out,called tape record.

Well, it is a variable out put and I'm running my M&K off it.
So, some older tube amps have variable out with the tape out..

I used to have a Rogue 99Magnum preamp and would occasionally run a sub off the tape loop. I have also run a sub on a different amp system using the high-level method described above. Both techniques worked fine.

If you're not constantly turning the volume up and down with wide swings use the tape out and set the volume on the sub to the normal levels you listen at , by using the high level speaker inputs you negate the crossover built into the sub....I get awesome results this way simply because I don't constantly vary the levels I listen at. If the sub volume ever becomes an issue I get up off my butt and adjust it rarely do I do this. Having a sub integrating with decent bookshelf's sound full and rich at medium and low volume. When a deep blast appears in a soundtrack or video it shows up .....