A/V Cables, Audiophiles, and Antennas

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A/V Cables, Audiophiles, and Antennas

Postby frezik » Tue Mar 02, 2010 4:13 pm UTC

I don't think I need to go into the rather . . . novel claims made by audiophiles. I'm sure the Monster Cable vs. coat hanger test is well known around here. Rather, I'm looking to check my logic with more knowledgeable people on how resistance might affect a cable's usefulness.

It's common for A/V connectors to be gold plated. Gold is malleable, has decent electrical resistance, and doesn't easily tarnish, making it ideal for the connection point. However, its also very expensive, and its resistance properties aren't better than more common elements:

Gold: 22.14 nΩ·m
Silver: 15.87 nΩ·m
Copper: 16.78 nΩ·m

(All taken from Wiki, measured at 20°C.)

Copper is actually a significantly better conductor compared to gold, and silver is marginally better still (probably not enough to justify its cost). A cable with complete gold wiring is a waste of money on this basis.

What I wonder, though, is if there's a breakeven point where lower resistance is actually undesirable. If you're lowering your cable's resistance, then you're also increasing it's qualities as an antenna and allowing it to pick up external noise sources. Things like cryotreatment, even if they have an affect that can be heard in a double-blind test (not likely), may in fact be counterproductive.
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Re: A/V Cables, Audiophiles, and Antennas

Postby thoughtfully » Tue Mar 02, 2010 11:00 pm UTC

Its not about the resistance, but the chemical inertness, as you mentioned. Gold contacts do not corrode, for practical purposes. They will probably rub off mechanically first. Anyway, it's generally just a thin plating (hardly any effect on resistance) on the contacts themselves (maybe the whole contact, if its sufficiently small, like a pin), not the whole cable, so the expense is minimal. Did you really think the expense of Monster cables was justified by materials?
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Re: A/V Cables, Audiophiles, and Antennas

Postby Goemon » Wed Mar 03, 2010 4:44 am UTC

If you mean that a solid gold cable might have better noise resistance than a solid copper cable because copper makes a better antenna and picks up more noise, I'd say completely irrelevant: the relative resistance of gold/copper vs. say air is pretty insignificant. And especially because resistance has so little impact compared to other factors like the SHAPE of the antenna. A poorly designed silver antenna could easily be less efficient than a well designed one made out of spam.

An audiophile nut friend of mine once showed my adds in one of his magazines for a pair of four meter long wires used to connect an amp to a speaker for $6995. I repeat: two wires. Take special note of the location of the decimal point in that price tag. Yes, it's really (US) seven thousand dollars. I really need to make some money off these idiots...
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Re: A/V Cables, Audiophiles, and Antennas

Postby 2.71828183 » Wed Mar 03, 2010 4:59 am UTC

This is the first I've heard of cryotreatment of audio cables. And wow, that site hurts my brain.

<rant>

First of all, the martensitic phase transformation that they mention occurring at cryogenic temperatures is unique to iron-carbon alloys, and has at most a tenuous connection with electrical properties anyway. (And "carbon carbide"?? I'm pretty sure they mean iron carbide, but of course they don't want to say that because some smart aleck will come along and point out that iron carbide has approximately nothing to do with copper audio cables.)

Then they go on talking about dislocations in the crystal lattice of the metal, which is approximately correct, except that cooling doesn't get rid of those. The process by which those strains are relieved is called annealing, and it's a well-known process used all over the place in industry. It involves heating the metal to where diffusion can rearrange everything so it's nice and orderly. Not cooling. And what does this have to do with electrical properties again? (I'm not 100% certain that lattice dislocations don't affect resistivity, but I do know that any effects that would be caused are very much negligible. I mean, it's a piece of speaker wire, not the terminal of some precision resistor. Variation in wire length due to manufacturing tolerances is going to change resistance a lot more than the level of residual strain in the wire.)

Finally, even if arcane process XYZ did in fact lower the resistance of a copper wire by some barely-measurable percentage, it would be a heck of a lot cheaper to just make a slightly bigger wire. Lower resistance guaranteed, no materials pseudoscience necessary.

</rant>

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Re: A/V Cables, Audiophiles, and Antennas

Postby Charlie! » Wed Mar 03, 2010 6:25 am UTC

Brilliant! The next big thing in audio-equipment-phile marketing: big-ass cables! Just giant logs of copper and insulator with a few hinged joints.
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Re: A/V Cables, Audiophiles, and Antennas

Postby frezik » Wed Mar 03, 2010 3:14 pm UTC

thoughtfully wrote:Did you really think the expense of Monster cables was justified by materials?


Nope, but I have yet to find out what the expense of Monster Cables are justified by.

Goemon wrote:If you mean that a solid gold cable might have better noise resistance than a solid copper cable because copper makes a better antenna and picks up more noise, I'd say completely irrelevant: the relative resistance of gold/copper vs. say air is pretty insignificant. And especially because resistance has so little impact compared to other factors like the SHAPE of the antenna. A poorly designed silver antenna could easily be less efficient than a well designed one made out of spam.


Thanks, that's what I really wanted to know.

An audiophile nut friend of mine once showed my adds in one of his magazines for a pair of four meter long wires used to connect an amp to a speaker for $6995. I repeat: two wires. Take special note of the location of the decimal point in that price tag.


Yup. Do these people realize that there is literally miles of plain copper wiring inside any amp? The few feet between connections is nothing.

I really need to make some money off these idiots...


I seriously considered it a while back, on the basis that trying to knock sense into them is like screaming at a tidal wave. Someone is going to get rich off them, so it might as well be me. I didn't follow through on the basis of having a (overdeveloped?) conscious, which is probably why I'll never be rich.

Look around any audiophile site for a while and you'll find all sorts of ways to make high-margin profit:

* Cryotreatment (dip cables in LN2 for a while, or dry ice if you want to be cheap and get exactly the same results)
* Cable break-in (hook them up to a sine wave generator for a week)
* Audio brick (brick that's been exposed to music for a long period of time, which you place next to your amp)
* Cable riser (bit of ceramic that keeps your cable off the floor)
* Cable gas (probably a CO2 canister that vents for a few hours)

Any one of these will get you all sorts of testimonials about how the music sounds "warmer", and will net you thousands in profit for a few bucks in costs.
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Re: A/V Cables, Audiophiles, and Antennas

Postby Coffee » Wed Mar 03, 2010 4:07 pm UTC

No wire hangers!
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Re: A/V Cables, Audiophiles, and Antennas

Postby po2141 » Wed Mar 03, 2010 4:14 pm UTC

Goemon wrote:A poorly designed silver antenna could easily be less efficient than a well designed one made out of spam.


I am skeptical of this....
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Re: A/V Cables, Audiophiles, and Antennas

Postby letterX » Thu Mar 04, 2010 7:33 am UTC

frezik wrote:* Audio brick (brick that's been exposed to music for a long period of time, which you place next to your amp)


Seriously? I've heard rave reviews from my ex-roommate about the wonders of the brick-mic (a mic duct-taped to a brick, placed near your kick drum), but this seems more like homeopathy than science? And people buy this?

Ah right. Homeopathy.

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Re: A/V Cables, Audiophiles, and Antennas

Postby Mr_Rose » Thu Mar 04, 2010 11:57 am UTC

letterX wrote:
frezik wrote:* Audio brick (brick that's been exposed to music for a long period of time, which you place next to your amp)


Seriously? I've heard rave reviews from my ex-roommate about the wonders of the brick-mic (a mic duct-taped to a brick, placed near your kick drum), but this seems more like homeopathy than science? And people buy this?

Ah right. Homeopathy.

Now, now; your ex-roomie might not be as crazy as that: I can see a point where attaching a microphone to a brick, effectively increasing its mass and possibly isolating it somewhat from seismic interference (better than a narrow, potentially resonant, metal mic stand anyway) might measurably (as in, with sensitive instrumentation) alter the way it picks up sound, especially on a flexible wooden stage, though I have my doubts about whether it would make a detectable difference to the untrained human ear once the final audio has been processed and reproduced.

The fabled "audio brick" though, really is homeopathy for AV nerds from what I can tell; you have a brick that has been "listening" to music for time period X which is then placed adjacent to, but not touching, electronic AV equipment Y - this produces an 'improvement' in audio quality produced by Y proportional to the distance between Y and the brick and the time period X, or something like that.
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Re: A/V Cables, Audiophiles, and Antennas

Postby Peter Galbavy » Thu Mar 04, 2010 1:10 pm UTC

Audiophiles - and I do not consider myself one, although I have some nice medium expensive kit - are generally easy prey. There is a pursuit for some sort of perfection that can never be satisfied and so when someone come along with a new product it is very hard to disregard it as simple snake oil. Then there is also the whole reference vs preference debate about the sound.

I can hear a big difference between the analogue stage in my Squeezebox 3 and my external DAC (Beresford Caiman) and *to me* the DAC sounds better. This is preference, since I have never measured the outputs against some standard. Another thing I cannot understand people who witter on about clock jitter in buffered digital streams - hey, kids, it's what the buffers are for! (Unless of course your DACs clock is so poor as to supply random intervals but then you may as well give up and turn the power off).

I can appreciate a good quality, well constructed interconnect cable, for example. I can't hear anything of a difference but I know that the cable I bought for £70 is going to cope with physial stress and being connected, disconnected, moved, packed, unpacked etc. much better than the £10 one. I cannot see the point in a cable that costs £1,000+ though. Especially when they promise esoteric materials and manufacturing "techniques".

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Re: A/V Cables, Audiophiles, and Antennas

Postby frezik » Thu Mar 04, 2010 3:05 pm UTC

letterX wrote:
frezik wrote:* Audio brick (brick that's been exposed to music for a long period of time, which you place next to your amp)


Seriously? I've heard rave reviews from my ex-roommate about the wonders of the brick-mic (a mic duct-taped to a brick, placed near your kick drum), but this seems more like homeopathy than science? And people buy this?


I couldn't find where I originally saw this. It was a more reputable manufacturer making fun of audiophiles by using a brick taken from a recently-demolished testing facility. I think they were specifically making fun of these guys: http://www.machinadynamica.com/machina31.htm

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Re: A/V Cables, Audiophiles, and Antennas

Postby Turtlewing » Thu Mar 04, 2010 7:09 pm UTC

If my experience with musicians is representative of the lot, than roughly 70% of them will given the chance try to turn the sencores to a midi drum kit upside down or backwards, and claim it "makes a better sound" that way. Those same musicians will also press buttons at random on the controle pad and later wonder why their snare sounds like a cowbell, or insist on putting their distortion effect processor between the guitar and recording interface, and later ask if the sound egineer can change the effect settings without re-recording.

Where I'm going with this is there are a lot of musicians who use technology with no idea how it works, and there are also a lot of musicians who learned how things worked 20+ years ago and don't realise things have changed. I'd expect prety much anything along the lines of "super low resistance" cables to be more marketing to the ignorant rather than any actual practical reduction in resistance/increase in quality.

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Re: A/V Cables, Audiophiles, and Antennas

Postby evilbeanfiend » Thu Mar 04, 2010 7:31 pm UTC

frezik wrote:
thoughtfully wrote:Did you really think the expense of Monster cables was justified by materials?


Nope, but I have yet to find out what the expense of Monster Cables are justified by.


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Re: A/V Cables, Audiophiles, and Antennas

Postby Jorpho » Thu Mar 04, 2010 8:29 pm UTC

Mr_Rose wrote:The fabled "audio brick" though, really is homeopathy for AV nerds from what I can tell; you have a brick that has been "listening" to music for time period X which is then placed adjacent to, but not touching, electronic AV equipment Y - this produces an 'improvement' in audio quality produced by Y proportional to the distance between Y and the brick and the time period X, or something like that.
At least that makes slightly more sense than the magic rocks or bits of wood that likewise get regularly sold. But only slightly. (After all, if the trick works with a brick, then clearly you can have better bricks!)

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Re: A/V Cables, Audiophiles, and Antennas

Postby Yakk » Thu Mar 04, 2010 9:05 pm UTC

evilbeanfiend wrote:
frezik wrote:
thoughtfully wrote:Did you really think the expense of Monster cables was justified by materials?
Nope, but I have yet to find out what the expense of Monster Cables are justified by.
profit
Profit both for Monster Cables (who make the fancy packages with all the logos), and the people selling the cables (who get to use that fancy packaging to charge 2 arms and 3 legs to the customer).
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