Coax for 50 ft long stereo unit speaker wire?

[priscilla7391]

I had coffee with a friend today and told him I just got 50ft of (9254 75Ohm) belden coax at $0.25 per foot.

He asked me if coax would be better than normal speaker hookup wire for a very long wire from stereo to speaker. Seems to me coax would be better even with modulated DC than unshielded hook-up wire, but usually it would be more expensive. There is also the resistive loss to consider. The spec sheet on this belden coax says about 6Ohms per 1000feet. I don't know what a 10 or 12 gauge speaker wire resistance would be per 1000ft.


But why guess when there are people here that can tell me and give good advice.

Open to suggestions here. I thank you!

 

[Sceadwian]

I'd hardly call 50 foot 'very long'. Shielding in power speaker wire is completely pointless, that's why it's not used. 10 gauge wire would be about 1ohm per 1000 feet. 12 is about 1.6 Coax looses. If you think about shielding on hookup wire... What's the point? Where's it going to pick up enough power to provide interference?

Actually I would considering using the Coax SHIELD to transfer the power... There's more conductor there than in the center =)

 

[mneary]

Are you sure it's 9254? Everybody lists it as 13-conductor shielded CCTV camera cable, with 9x22 gauge plus 2x 75 ohms co-axes.

Coaxial cable might be helpful if you're very near to a very strong E-M field, such as within a few hundred yards of a 100kW AM broadcast station or a 1MW analog TV station. Otherwise, as Sceadwain says, ohms per foot is more important. Your coax (assuming 6 ohms is a round trip figure) would be slightly better than 16 AWG.

 

[Sceadwian]

If you don't need the shield might as well cut it open and twist it with the center conductor, the AWG equivalent of that shield is probably HUGE.

 

[priscilla7391]

Thanks, I will pass this along to my friend.

Hmmm.... you ask why the concern about shielding on my part? - I guess I was remembering "AC" 60Hz "Hum" getting into speaker wires somewhere in my past.

========

My mistake on the coax number.
On the cable itself and everywhere in my notes it is 9248,
but somehow in my post I put 9254.
I guess my brain likes 54 better than 48,
maybe something to do with my birthday...
As you get older, these sorts of things happen.
Oh well what's six years when it comes to coax numbering

The coax is labeled all along it's length:
Belden - 9248 Duofoil-Braid 75 Ohm
AWM style 1354 VW-1

It is solid core, with Al foil wrapped along with the braid layer.

 

[Sceadwian]

Priscilla, 60hz AC has a wavelength of over 3000 miles. A 50ft piece of wire isn't going to pick up any power. If you have 60hz hum on your speakers it's from an improperly filtered amp, or a ground loop in the audio system. Hookup wires are run in parallel anyways, any interference they pick up would cancel out because a signal would be induced in both wires at the same time.