Building a theater and I bought 500 feet of 14 gauge CL2 for my speakers (obviously!), but I'm wondering if I can just use that for my subwoofer as well? Would it work if I just put RCA connectors on the speaker wire? Or do I need a special sub wire?
Thanks for any help!

Powered sub?

You should use 75ohm shielded RCA cable if you are using a line level output. Speaker wire will induce noise and can cause an impedance mismatch.


Ian

There's no impedance mismatch problem with analogue audio. It is well below the frequency where characteristic impedance begins to matter. The reason to use coax cable is simple noise. Since it is a high impedance, unbalanced connection it is rather susceptible to noise. In the case of subs, power hum is the big one. Thus you want a good, shielded coax cable. The characteristic impedance isn't important though and indeed Bluejeans sells a good audio cable that's not 75ohm.

So to answer your question: It will work, but is not the best idea. Instead, but a coax cable. Monoprice has good ones for plenty cheap.

Thanks. I bought one CL2 50-footer from Monoprice and put it in, but then I thought: What if I want to run two subs up front? I have all this leftover wire, but it sounds like I should just order some from Monoprice again.

Or can I just split the wire at the wall at the front of my theater?

And, yes, it is a powered sub (not quite sure, which one but it's from B&W)

You can simply split the output with a Y connector and hook it to two subs. The only concern for running more cable would be if you wanted to have them apart from each other and wanted it all hidden in the walls.

Perfect. The Y connector would be great. Hopefully you don't lose too much quality. And I guess I wonder if you actually get twice as much sub power through the same wire or if the sub power is just split and more evenly distributed throughout the room via two subs?

Anyway, if I want to put a sub in the back of the room, I can easily poke a hole through the wall from a storage room and the equipment closet.

A Y connector doesn't matter for line level inputs. All the devices should be high enough impedance that it changes nothing. You only need to worry about it if it is speaker level.

There are two different hookups in a HT system that we are talking about here. The speaker wire hookups are the ones that are just two binding posts that you can hook up bare wire or banana plugs to. These are low impedance, high current and are for non-powered devices. So if your speakers don't have an amplifier, and most don't those are what you use. On the receiver side, those outputs are hooked in to its amplifier.

The line level hookups are RCA. These are high impedance, low current hookups. These are only for hooking to powered devices. If you were to modify a cable and hook one up to a speaker, you'd get no sound since there's not enough power. However subwoofers usually have their own amps and thus you hook them up using this connector, letting their amp take care of driving the speaker, rather than the receiver.

So as long as we are talking about powered subs then what you want to do is use an RCA hookup, with a coaxial cable, and a Y-connector is no problem. If you are talking about unpowered subs, then this doesn't apply.

Sycraft ... thank you! That was an excellent explanation of something I had the foggiest about. Seriously, you summed it up nicely for me. I always wondered what that line level stuff meant on the back of my subwoofer! I guess it would help to actually read about how things work occasionally. Anyway, you've solved my problem.