James Randi Posts $1M Award On Speaker Cables

So for 20 feet of speaker cable, the difference is what?

Something in the 10-15 ohm range, usually.

John

The plating is micro-inches on top of a copper wire that's mils in diameter. And silver conducts only a little better than copper. So the net effect of silver plating on wire resistance is unmeasurable.

John

That patent should have easily failed the "obvious to someone skilled in the field" test as well as the "prior art" test. Oh well...

ChairmanOfTheBored hath wroth:

Well, I needed one as a refresher and so I could grind the numbers. Also so others reading my rubbish can do their own calculations. I usually include URL's with background info in my postings to backup my numbers and allegations. Try not to let it bother you.

Sure, but considering the typical silver 0.0001 to 0.0030 inch plating thickness, it doesn't have much effect on the overall conductivity of the speaker wires unless you make the entire cable out of silver. I wonder what that would cost?

I don't think one could easily measure the difference in resistance between copper speaker wire and the same wire with silver plating. You could do that at RF frequencies, but not at DC.

However, Joe Sixpack doesn't know that. Besides, silver plating looks cool, and sells well.

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

"GoldIntermetallicEmbrittlement"

Yeah, that's the usual response of the snake-oil salesmen in high-end audio - "if you can't hear the difference, well, then OBVIOUSLY the rest of your system (or your hearing) simply isn't up to par!"

Kind of like saying that if you see that the emperor is naked, you obviously need new glasses....

Bob M.

$8.00/foot, uninsulated:

Cheers! Rich

Like these?

Cheers! Rich

Wire is usually silver plated to 20-50 microinches thickness, which wouldn't change conductivity enough to matter.

John

Nobody who hangs out at high-end audio shops, or who has audiophool friends, would dare admit they can't hear the difference. So they hear it.

John

Madness"

examples:

(power)(sprk)

$1,319 for speaker wire? At that price, I'd expect the wires to be SOLID silver, not silver-plated copper.

Why not insist on having silver traces on the amplifier's circuit board, with silver RoHS solder, as well? Don't forget the epoxy layer afterwards (since silver will tarnish to silver sulfide over time)

Thanks for the laughs

Michael

Hell, even that's hard. Excerpt from my copy of the ARRL's 1966 Radio Ameteur's Handbook, page 450:

-=-=-

5) The plate circuit is made entirely of copper strap and tubing, for highest possible Q and low resistance losses. It may be of interest that the entire tank circuit was silver-plated after the photographs were made. Efficiency measurements made carefully before and after plating showed identical results.

-=-=-

And this was for a 50MHz, sorry, Mc(!), tube amp.

Tim

-- Deep Fryer: A very philosophical monk. Website @

Hey, has anybody ever published an audio review where they said "I couldn't hear any difference"?

John

Rich Grise hath wroth:

Thanks, but there's a problem. It's not insulated. Still, it's cheap enough to easily sell in the seriously overprice audiophile market. My guess(tm) is that the 12AWG stranded will go for about $10/ft with insulation (or $20/ft for a pair of cables). Let's see how that compares with audiophile speaker cable:

I'll pick the cheapest, which conveniently also comes in 12AWG.

Hmmm... $420/10ft = $42/ft which is twice as much as what I guess(tm) solid silver cable will cost. Double is a nice markup, so I guess solid silver speaker wire can be sold to those that want only the absolute best.

Stay tuned to this newsgroup for the next big thing in marginal and overpriced audio paraphenalia.

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

Absolutely incorrect.

SPC has a lower resistance than bare copper or TPC. It is right there in the specs.

You: Stupid... guilty as charged.

The wire: better... just as was stated.

Do the math. Show us.

John

It was a tank box. The entire goddamned thing is at ground!

Of course there will be no difference.

ChairmanOfTheBored hath wroth:

There are no absolutes. Everything is relative.

SPC? TPC?

11th Commandment: Thou shalt not abrev.

Specs? Where?

Let us grind some numbers. From:

Resistivities at room temp: Element Electrical resistivity (microohm-cm) Aluminum 2.655 Copper 1.678 Gold 2.24 Silver 1.586 Platinum 10.5

That makes silver slightly better than copper or: (1.678 - 1.586) / 1.678 = 5.5% better However, that assume we're comparing equal amount of silver and copper. With silver plated 12AWG copper speaker wire, there's considerably more copper wire than silver plating.

Grinding some more, 12AWG copper (solid) wire has a cross sectional area of 2.053 square millimeters for a radius of: 2.053 mm^2 / Pi * r^2 r = 2.54 mm radius

Assuming a typical silver plating layer, but as thick as possible, of

50 micro inches or 0.00127 mm of silver plate. That's a cross sectional area of: Area = Pi * (r2 - r1)^2 = 3.14 * ((2.54 + .00127) - 2.54)^2 Area = 3.14 * .00127^2 = 0.00001 sq mm silver

That's about 2.053 / 0.00001 = 200,000 times more copper than silver for 12AWG solid wired based on cross sectional area.

I'm too lazy to work out the parallel resistance of the silver plating and the base copper. Suffice to say that 0.00001 sq mm of silver is not going to have much of an effect on the resitance of 2.05 sq mm of copper, when the resistivity is only 5% different. If we switch to stranded wire, there will be some more silver plating, but not enough to make much of a difference. (It's also almost midnight and my brain is rapidly turning to mush.)

Are you an audio equipment reviewer?

Next step, cyogenically cooled speaker wire.

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

"Tim Williams" hath wroth:

The earliest ARRL Handbook on my bookshelf is from 1980. However, I have Antenna Handbooks dating back to 1960. Lots of good info, even in the old issues. Also, lots of mistakes in some later releases. (Drivel: I collect some old technical books).

What they're doing to raise the Q (by lowering the surface resistance) is to increase the surface area by using tubing and flat wire strapping instead of comparatively thin wire. Skin effect is highly dependent on surface area, the more the better. For high Q, you need fat coils. Notice that they use tubing instead of solid wire stock. That's because at 50MHz, all the conduction ocurrs near the surface of the conductor, and not much ocurrs near the center. So, you don't need the center and can therefore use tubing.

However, this has nothing to do with what I was mumbling about. The issue under discussion are audiophile gizmos and specifically speaker wire. At audio frequencies, skin effect has almost no effect on conductor impedance. Same with silver plating.

Things work quite differently at 50MHz than with audio. Also, a tube is what you roll toilet paper on.

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558