So, I'm planning on running some wire in my basement to two new rear center speakers, and was checking out what speaker wire I had left on a roll when I notice a snipping of the 12 guage wire I used when I first ran the rear left/right about 8 years ago.

Not only has the clear vinyl jacket gone all sticky, but the wire inside is no longer shiny - it's dark green over about 95% of the surface and looks (and feels!) quite bad.

Some wire I purchased a year or two after that is still bright, shiny and doesn't leave an unpleasant residue.

So what's the deal here? I'm thinking of going to the trouble of replacing both old runs (about 80 feet of wire). Anything to look for to ensure that whatever new wire I buy *doesn't* do this?

that is not uncommon here in the great Pacific Northwest. It is usually Munster like wire and it can be so bad the conductors corrode the whole length of the wire and it "crunches"when you bend it.It is worst near the ends.You then have to cut the ends back untill you get less bad (it's never good)wire. Replacment is your best option if possible. Your best bet is some better brands of wire (Belden,Liberty,Audioquest,Comscope,etc)

The outer housing is in such bad shape it's almost impossible to read the printing on it... but it's "Ultralink Audiophile Reference Series 12 Gauge 518 Strands".

Oxidtaion will cause the exterior of the strands to corrode.
It will still work, but looks like heck.
The oil products in the jacket are breaking down from the smae malady seen in old foam surround speakers.
The foam literally breaks down into oily gel from ozone.

Use a CL3 or CL4 rated speaker wire, as it meets most codes, and in the case of a fire, wont act like a candle wick and burn.
If this wire is going into a really damp environment, maybe consider "direct-burial" wire.

The green surface crap will eventually eat away at more and more of the wire's thickness, resulting in signal loss etc.

You might also consider speaker wire that has been "tinned" to reduce oxidation from exposure (used on marine installations).

Even if it is kind of a pain to do, I would replace those runs...

Did you ever figure out your Sub-Woofer situation?

I am sure you probably already plan on replacing the speaker wire because that's all you can do at this point. I would definately use a Beldon or Liberty Direct Burial Wire just to make sure it doesn't happen again. I know the other wire was not intended for wet locations but still, anything that oxidizes like that isn't good for anything over time. I would hate to have used that particular wire for any installs I had done!

Daniel,

I'll inject a bit of engineering into this: The greenish color is oxidation of the copper. This is likely caused by the jacket breaking down, and reacting with the copper.

The good news is that I've never seen a situation bad enough to actually hurt the electrical characteristics of the wire. You've only lost a few microns worth of copper from the surface. This is far less than the error bounds of measuring wire gauge during the manufacturing process.

The oxide will act like an insulator, so it is important to clean the ends of the wire thoroughly! Cut off as much of the old ends as possible, and then clean the new ends. You will find a mild acid helpful, lemon juice will work well. Rinse with clean water, and then test with your ohmmeter to make sure you have conductivity. The copper will not look bright and shiny, but you only need to get rid of the non conductive oxides. The outer layer of copper on the individual wires will be discolored due to contaminants due to the oxidation process, but these will be conductive, and surface only, so not a real concern.

Replacing the wire may make you feel better, but you won't be able to hear the difference. I'd suggest saving yourself the work and trouble, unless you're planning to tear into the walls anyway.

I have seen a case where the oxidation of speaker wire has been so bad that the speakers wouldn't work. Cut back to clean wires and the speakers would work....

Resistance issues a possible reason?

9 years ago, I burried standard jacketed 16/4 & 16/2 to run the speakers in the back yard. Longest run about 100'. A few months ago, I added a speaker with new wire running directly from the outdoor volume control. I was surprised to audibly hear the difference in quality even after replacing all the connection ends. The sound was more crisp and the volume perhaps a little louder than the 2 with the old wire. Each speaker is the same age (about 1 year) - Niles OS-6's. I've used dialectric wire nuts for the outdoor wiring.

When it gets less hot (it was 118 on Friday) I'll retrench and replace the old stuff - and this is a "dry heat" (not a lot of moisture).

Any comments?

Yeah, 118 deg? Man, that's hot! It's about 90 here and that's hot enougth for me.

Yes, remember to lift with your knees, not your back when shoveling. Drink plenty of water, too.

The fact that you cut it back, and it worked fine, supports my point. The oxidation is non conductive, it acts as an insulator. Remove the oxidation where you make the connection, and it won't matter if the wire is oxidized elsewhere.

make sure you get direct burial speaker wire when burying it in the ground.

The crazy part is this ISN'T a damp environment... far from it. My house is fully air conditioned and tends to run on the dry side all times of the year.

I had no idea what brand it was when I originally posted; but an Ultralink cable should have been better than this. Especially when a 100 foot roll bought from CostCo for $25 is holding up better!

It reminds me of a series of pens that I liked about 10 years ago or so... they were one of the early models with a large soft rubber grip, over a metal shank (copper? brass?). I discovered that after several years the rubber would start to get extra squishy and tend to "stick" in odd shapes. So, one day I took the pen apart, pulled the rubber part off the shank, and the metal was completely coated with a layer of black liquidized rubber.

Since this is a dry environment, I'm more inclined to think that the breaking down of the casing is causing the oxidization of the wire... and the problem is likely only going to get worse. :-(

You're right Daniel. It doesn't need to be moist for this issue to happen. Although moisture will accelerate oxidation, it's not likely contributing to your problem.

Many companies jumped on the bandwagon for the fat Monsteresque clear coated speaker wire, and they didn't put too much time into engineering of the jacket. The decomposition of the jacketing is the cause of the oxidation, or 'greening' of the copper. As long as you have good contact at the amp and speaker ends, the signal will still pass. Over time, it will get worse.

Get some new cable.

I refuse to get in an argument with the king of the flat-earth society, so I will just echo everyone elses recommendations and say replace the wire with some good cl rated 14/4 and go on with your life. If you twist the pairs together you get 11ga, and that should do perfectly fine, if not a bit of overkill.