Cable technology question (audio quality)

nsaspook

One of my most valuable job experiences was working in audio sales while attending school in the 1970s. I mainly worked as a technical guy who fixed equipment in store but also as a salesman.

The first thing we learned was to size-up the amount of money in the costumers 'mark' pocket. The second thing we learned was not the laugh at the sucker until the check cleared.

nsaspook

True, but compared to the nonlinear device called an 'ear' audio frequency electronic devices are models of perfection.

sophiecentaur

HiFi electronics is crammed full of capacitors - (many electrolytics, in particular) both in the Power Amplifier and in the Crossover units (they're not all active these days, are they?). How many amplifiers are selected on the linearity of their capacitors, I wonder? I know that 'harmonic distortion' is the watchword of amplifier linearity but Intermodulation Distortion is a far more sensitive test because the products can be made to fall in-band (as they do in your ears).

Everything is non-linear in the end and the weakest link is surely the one to go for first. The customer can see the connecting cable and both ends of it, at the terminals. I'm sure he (and it is mostly "he"'s involved in this) is very likely to be suckered by the salesman's "of course, Sir, you won't want to spoil it all by buying budget cable." and by the shiny wires and the sexy transparent sleeving. He's less likely to be checking all the internal solder joints with a lens, which is where you can definitely expect to get the occasional spot of non-linearity after a few months of running warm.

I really am a grumpy old sod when it comes to wasting money - even other peoples'.

AlephZero

The sort of people who buy from websites like http://www.hificollective.co.uk/comp...apacitors.html

When parting fools from money, nothing is off limits!

sophiecentaur

What a great site. I see they actually offer 'Beeswax' capacitors!!! After a few years of 'warm runnings' under a thermionic valve they get an attractive coating of house dust (mostly discarded human skin cells, I understand).

But I couldn't find any mention of Linearity ??

gresit

ok, since this deviated from the original subject (but please skip to the end, there's something interesting there), why not.

one nonlinearity does not necessarily mask another. what counts is what the ear/brain system "thinks" about the combined result. a mere figure or even plot is not too telling without a proper understanding of the psychoacoustic phenomena.


no, most speakers are still passive although there are a few full "high-end" active designs. some caps are better (but not necessarily expensive) than others, good speakers use the good types. my speakers used to cost $7k new (no, only paid a small fraction of that, bought used) and the caps are few dollars a piece but quality ones (Solen brand).

you would not believe. many amplifiers/preamplifiers/etc use very expensive caps. some go to extreme lengths and eliminate all decoupling caps from the signal path, even giving up DC servos. I know about people who burned very expensive woofers because a defective CD player or whatever sent DC to the amp.

harmonic/intermodulation distortion measurements are different ways of looking at nonlinearity and yes, IMD tests are more telling because they also tell about the source of nonlinearity (if high frequency tones are used the results are an indirect measure of slew-rate limiting too).

valid points, but the "high-end" audio equipment is sold through distributors who set-up demo systems and many actually demo cables (including A/B comparisons).
about damaged joints, you're right. these types would not take the lid off their beloved amp because they think it's sooo super high tech and irreparable damage will be done by non-audiophile air entering it, let alone look at solder joints.

I think the real problem is that there's a small portion of extremists (euphemism for lunatics) among them, but the "non-enthusiast" views them all the same. I think they're not.


returning to original question, I ran a generic Google query, excluding everything audio related. found this link: http://www.habia.com/MARKETS/Industr...onSensors.aspx
looks like a generic industrial cable manufacturer. from website:

Vibration and Acceleration Sensors
Cables required are generally referred to as low noise cables. Suitable for use in the measurement of weak signals which may be susceptible to self induced noise within the cable. Mechanical disturbance of a cable (vibration, bending, twisting) can cause voltage spikes with magnitudes of tens of milli-volts. This noise is due to triboelectric charging of the insulator materials, which act as capacitors to store the charge.

one thing I can tell you is that tens of millivolts is A LOT, even at speaker input.

and they go on:
The Habia solution to reduce the effect of the problem is to introduce a carbon layer between the dielectric and screen resulting in any charges formed from movement or pressure to be rapidly returned to and from the screen. This effectively traps any unwanted signals.

the carbon thing reminded me of an audio cable manufacturer who uses a similar technology, it's called Van den Hul. they're among the more down-to-earth guys. Googled a bit more and found this guy who tested a few guitar cables: http://www.thegearpage.net/board/arc.../t-276746.html

he says:
Cables with dullest thump in ranked order from dullest to less dull: (lowest microphonic characteristics)

a. van den Hul Integration Hybrid (The unique Hulliflex outer jacket helped with this IMO - the inner layer of PVC is also the thickest of any of my cables)

b. Sommer Stratos (very, very, thick outer jacket)

c. Vovox Link Protect A
...

obviously, not the most scientific procedure, but if looks like the VDH won, maybe not a coincidence?

and I return to my suspicion... I personally think that at least some of the claims of audible differences are true. but I also think that many of these "high-end" manufacturers just use known, proven technologies from other fields in a fancy suit (with 50x profit margin) or even buy from generic makers like the one above.

gresit

have you spotted the 2k+ Audio Note cap? :)
you will never find any objective data with these guys, that's a given.

nsaspook

At least capacitor construction and dielectric types have some correlation to signal transmission.

These are the kind of 'cable' madness products made from pure 'snake-oil'.
http://www.musicdirect.com/p-971-cable-elevators.aspx
http://www.musicdirect.com/p-2378-sh...wer-cable.aspx

gresit

$1750? meh, beginner level.
if you want to have fun look for Nordost brand.

nsaspook

Sure, we use special PTFE cables for the control coils and pickups inside some of our CD-SEM electron-microscopes at work but it's working with signals in e-13 vacuum with 500ev nano-amp currents from a field emission tip electron generator and costs millions of dollars.

Apples and oranges from hi-fi audio unless you need to listen to JSB during an earthquake.

Speakers will always be the weakest link with accurate audio reproduction because it's the interface from electrical to mechanical. The common circuit models used to understand the transformation of electrical energy into mechanical energy requires a large number of nonlinear elements that result in acoustic energy changes far in excess of any possible cable caused signal interaction in a normal stereo system.

http://www.klippel.de/uploads/media/...ameters_99.pdf

nsaspook

No need. I've been a member over at AVSFORUM from 2002 and have seen almost every silly audio thread possible.

http://www.avsforum.com/g/u/42824/mntmst/photosets/1/

gresit

if you google for "Nordost Thor" you'll find the innards of a $3300 "passive line filter". you're not complete until you add that experience to your audio resume :)

gresit

ok, based on my Internet research it looks like what's generically called a "low noise cable" fits the original question. looks like graphite powder to mitigate triboelectric effects is the key ingredient. I can bet those cost $0.5/meter in small quantities :))