I know this topic comes up every six months. I thought that I bookmarked it but can't seem to find the bookmark. I tried the searching past posts and can't find it. Can someone give the recommended gauge of speaker wire for different lengths that I may run. I think that my length will be about 60 feet.

- Nick

Nick,

A simple solution is to simply use 12-gauge for any length greater than 20 feet. Even at 60 feet, 12-gauge copper wire has insignificant resistance.

For lengths less than 20 feet, 14-gauge is fine, and for short runs 16-gauge presents insignifcant resistance.

Regards,

Alan

Nick, though not much more than Alan's suggestion is needed, you are probably thinking of the ubiquitous Roger Russel Wire Table

Do you get bonus man-points for using 10-gauge all around?

Jack's link above should help you out on what type of wire to use for various lengths and speaker types.

When I built my house in 2004, I bought 12 ga speaker wire at Home Depot. Since then, the wire has begun to turn dark, I presume from oxidation. It has not affected anything yet, I thought I would throw this out for comment?

Hi Argon,

Copper does oxidize over time when it's exposed to air--you know those rooves made of copper that turn greenish, as well as copper pennies. Where it's exposed at the connection point, electrical conductivity may be affected. You can use a bit of sandpaper to remove the oxidation if you are using bare-wire connections and return the lustre to the copper.

If memory serves, it seems that other forum members have warned users away from Home Depot's bulk generic speaker wire because it seemed to oxidize even under the plastic insulation, which is odd. Even so, that won't affect conductivity through the copper.

Does anyone else recall those posts?

Regards,
Alan

I have not heard that with Home Depots speaker wire but I have read on other forums various times of Monoprice speaker wire oxodizing under the insulation.

I don't recall what brand of wire but I have experienced what I think was oxidization under the jacket. The clear plastic ended up turning yellow in spots. It did not cause any performance issues.

Hmmm. I've never tried the monoprice speaker wire. However, I've used SoundKing from http://www.partsexpress.com and it's still fine after a decade or so--nice and shiny under the clear insulation.

Regards,

Alan

You mentioned that the cooper would turn green if it is oxidizing. Now if there is yellow discoloration under the jacket is this just a reaction of the plastic or is there some possible oxidization occurring?

Hi,

I'm not sure but I suspect it's some aging reaction of the clear polyvinyl jacket. Whether or not that is triggered by oxidation, I just don't know. What puzzles me is how the copper could oxidize beneath the jacket unless somehow oxygen got into the wire beneath the jacket during the coating process.

Virtually all copper speaker cable is sourced from China so it may vary depending on the vendor's source. I mean, why is our Axiom speaker cable super flexible whereas the SoundKing stuff I got ages ago from Parts Express is definitely stiffer. Maybe the latter doesn't have as many strands.

I remember when we introduced the Axiom generic speaker cable, someone at our Dwight factory counted the strands, and it has 275 strands per conductor.

Alan

Working from home today so I checked the 2 year old runs of Home Depot wire and so far, no oxidation on exposed or within the clear sheathing. 2 years isn't a horrid long time but it was worth checking while you had it on my mind.

Dude, that was a sucky job!

Stange. The batch I received had only 274. Can I ship them back to have the missing one pushed back in?

Alan used to love popping in when the guy got to 265 and start yelling, "85, 62, 113, 9745, 12"!!!!!!!!!

Yeah, that sounds familiar. Can't remember who or where, though.

Not surprising, really.

I think the discussion was brought over from AVS. I am quite sure I have read that wire oxidation thread.

I love how flexible the Axiom speaker cable is. It made my installation so much easier.

I remember reading about oxidation under the plastic/vinyl. That is exactly what has happened here - which I don't understand either. I would consider replacing except that it is all in wall and some rather long runs. So....unless I start having problems, I guess I will leave well enough alone.

nice hat!

Where's Jimmy?

Rob, without going into the full chemical story again, when copper oxidizes(due to atmospheric oxygen)it turns brown and almost looks black as the reaction proceeds(e.g., very old pennies). A greenish color would be due to a reaction with other elements, most notably chlorine. The greenish color reported under some transparent speaker cables isn't due to atmospheric oxygen, which doesn't penetrate the jacket. Apparently some of the PVC(polyvinyl chloride)jackets(most are okay)were unstable and broke down so that chlorine reacted with the copper, forming the green chloride.

As Alan pointed out, oxidation on the end of the wire can be easily removed with an abrasive such as sand paper, or the end can be trimmed and re-stripped.

The linked material by Mr. Russell is an excellent explanation of speaker wiring in general, in addition to the gauge table, and has undoubtedly helped many avoid wire rip-offs the past few years.

I'm going to develop a new speaker wire. Each strand will be microscopically thin, but there will be 20,000 of them per 12 guage (it will all be 12 guage) run. That's one strand per bandwidth from zero hz all the way up to 20,000 hz!!! Of course it will be oxygen free and one directional and all that other good stuff... but the 'one strand per bandwidth' will be the kicker! Every 'true' audiophile (wink, wink) will have to have it. And of course if while stripping the wire you happen to accidentally happen to cut a few of the strands off, you will have to replace the whole run. I mean that's a given, other wise you'll lose out on those frequencies that they were assigned to!

Micah, no doubt you'll be able to find some "audiophiles" who'd pay handsomely for such a miraculous wire.

Why yes, yes indeed! I'm taking pre-payments for anyone who wants to be the 'first' in line for this new miracle wire!!!

will your new speaker wire made me dancing with it? :p

I would say the color I am seeing is darker than greener. I don't know where this wire would have come in contact with chlorine. I do have some fishing rod holders that my wife's grandfather made for me years ago. He hammered 3/4 copper tubing flat and bent it around and attached it to a wooden stake. Quite clever, actually. 25 years later, the copper is taking on a nice green patina. After your comments about chlorine, I am not sure if it is the saltwater exposure or the fact that I always hose them down when I get home with tap water that is causing the patina. Probably saltwater?

Thanks everyone for the helpful information. I use 12 gauge oxygen free Soundking wire for my home theater for overkill, even though I have some short runs. I was hoping that I wouldn't have to use the same 12 gauge for my 60 foot run of some Aperion Audio speakers that I won from a contest and am mounting in the kitchen for some background music. Well, I guess I have to get some more of the heavier 12 gauge wire.

- Nick

That's odd. I had a problem with 75 ohm sub wire recently (Esoteric Audio Luminis wire) and noticed that it had a green powder I would call corrosion for lack of a better term. After I pulled the tip off, it turns out the shielding braid (copper in appearance) is covered in green powder, but the central core of copper is still nice and red - although the wire is now 10 years old. But odd none the less as it has not bee exposed to chlorine. I only knew it had a problem because it sounded bad - i.e., would not always trigger the sub on, etc. I have some pics of the green powder coming, but upload is taking a long time.

Could the salt in the air be causing a chemical reaction and forming Chlorine, or at least the Chloride could be causing the reaction?

Here is what I was talking about.

Hi JohnK,

Thanks for the chemical explanation and of course---duh, PVC, polyvinyl chloride, is where the chlorine factor comes in. I've said "PVC" for years without really thinking of the chemical composition.

So I think we can conclude that some PVC jackets become unstable and leach out chlorine, which reacts with the copper, producing the greenish color.

Regards,
Alan

Guaranteed! Or, you get 37% of your money back!!!

Excellent, informative post....(as always)

You only forgot one thing. You should have reminded everyone who uses this type of speaker wire (lamp cord) to be sure and buy it much longer than needed........the ends will need to be trimmed and re-stripped, many, many, many, times.

Also, my speaker wires are doing fine.

(see Avatar)

Larry, the copper in the various types of cords(regardless of how much they cost)is equally susceptible to oxidation from atmospheric oxygen or other elements. Money can't overcome the laws of chemistry. Haven't had to clean or trim my lamp cords for a few years.