[Split]Technical split from: Pear Cable CEO Calls James Randi's $1 Million Offer a Ho

[tot]

Actually, there is doubt, some people strongly claim otherwise. That is part of what would need to be studied, the range of measurable differences between cables, and in what ranges the human hearing sense is capable of detecting differences.

I'm not talking about obvious measurable differences caused by, for example, introducing a large capacitor or some fancy circuitry in parallel in the middle of the cable. Just differences in the regular cable parameters, R, Z, L and C, caused by material, geometry, insulator, connectors, solder, shielding, and/or other regular components or characteristics of a speaker cable.

Speaker cables are probably the easiest to manipulate. Just increase R or Z and the dampening of the driver is greatly reduced. I have no particular experience of speaker cables per se, but I have measured headphone cables with R over 1Ω -- would you use that kind of a cable to drive a 4Ω speaker?

124 posts have been moved here from http://www.internationalskeptics.com/forums/showthread.php?t=95361
You may find some of these posts responding to posts that remain in the original thread. The intention has been to keep the thread in the Million Dollar Challenge section as on-topic and specific as possible.

Replying to this modbox in thread will be off topic  Posted By: chillzero

 

[rsaavedra]

I have measured headphone cables with R over 1Ω -- would you use that kind of a cable to drive a 4Ω speaker?

No I wouldn't.

This is off-topic though, but since you ask.

I know people who use headphone cables made of palladium, a terrible conductor compared to silver or copper.

But some headphones have rather large impedance, 100, 300, and 600 ohms. Let's say it's 300 ohms. 300 vs. 301 ohms doesn't mean much difference as a load for the headphone amplifier.

But 4 vs. 5 ohms are much largely different loads for a speaker amplifier though.

Can't post links but I will post a quote from Amb on Head-fi, when I inquired about adding resistors in series with speaker cables, he explains in great detail the problems such a change causes:

I wonder if it would be too bad an idea (sound quality-wise) to put a high watt resistor in series with the speaker. Just to bring up that minimum impedance to let's say 9-10 ohms (a resistor of 5 ohms would do), in order to minimize potential challenges to amp stability.

Yes, very bad. If the small resistance of a fuse is bad, then a resistor of several ohms is real bad. There is a reason why thick, heavy gauge wires are usually advocated for speaker use... to lower the impedance. To add a resistor would be the antithesis of that.

As I mentioned above, the resistor will cause power loss delivered to the speakers. Let's say you use a resistor that is the same value as the nominal impedance of the speaker, then if the speaker impedance was perfectly flat you would have added a voltage divider that loses half the output voltage of the amp. The result is that only 1/4 of the power would be delivered to the speaker. In reality, since the speaker's impedance is not flat but vary wildly with frequency, the voltage divider action is not constant with respect to frequency, so that resistor will introduce significant frequency response changes.

What's more, in a properly designed vented or sealed speaker, the enclosure volume (and vent design) are carefully tailored to the woofer for optimum performance (this is called "Thiele-Small alignment"). One of the three important parameters is the total system Q ("Qts"), which comprises of electrical damping ("Qes") and mechanical damping ("Qms"). The electrical damping portion assumes an amplifier output impedance of zero ohms (or very close to it). By inserting a resistor in series, you will cause a change to the total Q and alter the speaker's bass response from the designed target.

Usually the audible effect of inserting a resistance in series with the speaker (other than a loss of power) is the muddying of the bass.

Edit: I should also mention that if the speaker is a multi-way design, then the series resistance will also wreak havoc with the crossover network response, causing further frequency response anomalies. In short. resistance in the speaker wire, whether it's in the wire itself, a fuse, or gasp, a resistor, is bad, bad, bad.

You can search any text from that quote and find the original thread and post on Head-Fi where it comes from.

 

[sthomson]

Suppose they were selling really expensive camera lenses, designed for the kind of cameras that don’t have the lens built in. They let you know that you can use their lense with “any” SLR camera body. That’s not the same thing as saying it will turn your camera into a better device.

So say you want to test out the claims about this lens. You could put it on some low-resolution digital camera (or pick the low-res setting) and “prove” that it is indistinguishable from other lenses.

There are high-resolution viewing systems, and high-resolution sound systems. Both kinds require the entire chain to be up to snuff.

High-resolution TV screens we have now reveal things that are downright embarrassing in, say, old Star Trek episodes, where the makeup looked OK on 1960’s TV but looks laughable on better stuff.

Sound systems have the equivalent in high-resolution versions.

I understand what you're saying; I'm not an audio engineer, so it'd be helpful for me to look at freq. response plots for "low-caliber" vs. "high-caliber" audio hardware.

Would it be possible to list some hardware that you would consider to be acceptable?

On another note, Inkler, have you done ABX tests with Monster cables vs. standard cables? With Monster cables vs. super-expensive cables?

 

[Inkler]

I have never done ABX tests.

I am not really here to try to talk about test protocols, though I see there is a strong tendency in that direction. I’m hoping to fill in some blanks for people unfamiliar with the hobby (or cult, if you prefer) of high-performance sound reproduction.

One such bit of information is that there is a lot more to accurately reproducing a music signal than obtaining a flat frequency response.

Going by specifications alone is as oversimplified (to belabor the wine analogy) as judging wines by their acidity, sugar and alcohol content.

Instead of leaving you with something that sounds insubstantial, I will offer one important parameter that is not on the spec sheets: how well does the speaker reproduce the detail in the sound? One set of speakers will sound a lot clearer than another, and it is not an illusion due to something going on in frequency response, but rather how quickly the moving parts can respond to the ever-changing signal. The moving elements in a speaker have mass, and thus inertia. Traditional speakers have a hard time not blurring the signal. There are kinds of loudspeakers that do not use any cones, but instead use as a moving element a feather-light thin film, controlled by a sandwich of electrostatically charged plates. These speakers are able to present information that others veil.

I’m not here to fight, and I see a somewhat pugnacious attitude from several posters. I’d rather ignore the fighting and offer a bit of information, to enlarge the knowledge pool.

You can think of “audiophiles” as belonging to another culture. You might want to learn a bit about their values, what it is they are after, what they do besides evaluate cables (as the optional final, finishing touches on a most carefully-chosen system).

 

[Gravy]

From

ECSTATIC review:

What on Earth is all the arguing about? I mean, who can disagree with such joy? Stick the wires in your ears and ENJOY for hours and hours!

Just have Randi mail the Million and be done with it.

I'm , Absolutely,

Take a look at the batpoo crazy stuff that Dave Clark, the reviewer of the Pear cables in Positive Feedback Online (guaranteed!), uses in his personal system. Coincidentally, most of these items were reviewed by Clark in Positive Feedback Online.

"Tons of Shakti Stones and On-Lines"...Shun Mook Original Cable Jackets (from the maker of the legendary Mpingo Disks)... Bybee XLR Golden Goddess Tails and Slipstream Magic Bullets..."Various Marigo VTS Dots used extensively throughout the system and room"...Shakti Hallographs (Only $1000 a pair!)..."Various Peter Belt treatments"...Walker Audio Ultimate High Definition Links ("Cryogenically treated," only $650 per pair (Vivid fluid extra))...Walker Extreme Super Silver Treatment ("produced a very substantial gain in system synergy")...AudioDharma Cable Cooker (because after you cryogenically treat your cables, they must be cooked. Everyone knows that.)...and the Clever Little Clock.

The last item, like the Tice Clock, is a clock (The Tice was a Radio Shack clock). Unlike the Tice Clock, the Clever Little Clock doesn't connect to the audio system, or anything else. It's battery-powered, but don't replace the batteries with store-bought models: contact the CLC people (read: Peter Belt) to purchase their special batteries. You put the Clever Little Clock in your room, and it improves the sound of your high-end audio system. By magic. From the manufacturer:

The Clever Little Clock is pre-set by Machina Dynamica and should NOT be re-set or adjusted.

Thus eliminating its only useful feature: telling time.

Machina Dynamica reserves the right to use more than one brand/model to produce Clever Little Clocks, so don't be alarmed if the Clock you receive is not the exact one in the photo. All versions of the Clever Little Clock are sonically equivalent. "

Yes, I'm quite all versions are sonically equivalent! The CLC reviewed by Dave Clark is a $10 Timex alarm clock with a fabric dot glued to its face. Retail price: $200.

A review from a happy user:

"I have a stereo system on one side of the house and a home theater system on the other side. I started off putting the clock in the room with the home theater system where I noticed a better picture - smoother and more film-like. Then I took the clock to the stereo system room - big improvement in the sound!! Then I took the clock back to the home theater system, and when I returned to the stereo system the clock's effects were still present. Also, the clock worked quite well in the car."

Sorry for the derail. I had to vent.

 

[sthomson]

I have never done ABX tests.

ABX tests are a way to do a blind test without many complications, and they're relatively easy to do solo, with a little preparation. Honestly, I would not trust anyone's qualitative evaluation of a difference in components without a few ABX trials. As an audio enthusiast, I'll assume that you've heard of this method, or should I provide a description?

Instead of leaving you with something that sounds insubstantial, I will offer one important parameter that is not on the spec sheets...but rather how quickly the moving parts can respond to the ever-changing signal. The moving elements in a speaker have mass, and thus inertia. Traditional speakers have a hard time not blurring the signal. ...These speakers are able to present information that others veil.

I certainly understand the limitations of devices to capture and transmit analog signals, although in the case of an analog audio cable this should not be a problem (unless we start thinking on the quantum level). Now, the criteria you mention - the intertia present in the speaker cones that "blurs" the signal. If this is something that qualitatively and quantitatively affects the sound quality, why isn't it capture anywhere in the documentation? How do audio enthusiasts measure and differentiate hardware based on this criteria? These are standard engineering questions that I would ask about any product.

I’m not here to fight, and I see a somewhat pugnacious attitude from several posters. I’d rather ignore the fighting and offer a bit of information, to enlarge the knowledge pool.

I don't see these posts as argumentative, but some of us may be impatient and opinionated. I'm not saying that there's no detectable difference between PEAR cables and my crappy RCA cables, but I certainly don't believe the evidence they've presented on their site, and from my own knowledge of recording techniques, buying fancy cables seems like polishing coal and calling it a diamond.

Edited to add: But I'm certainly willing and happy to be proven wrong.

You can think of “audiophiles” as belonging to another culture. You might want to learn a bit about their values, what it is they are after, what they do besides evaluate cables (as the optional final, finishing touches on a most carefully-chosen system).

Should selling $1000 cables that are essentially snake oil be allowed in any culture? What if you could get the same performance with $50 cables?

 

[Inkler]

Oh dear. “Batpoo crazy” might be about right.

That list of moonbeam stuff is embarrassing.

That’s, I’m sorry, really truly embarrassing. I don’t associate myself or any of the people I know with stuff like that.

There are fringe elements, and I won’t defend them in the slightest, because they make the relatively sensible people look bad by association. I wish they would go away.

I feel this particular challenge has crossed a line – and not previous ones to objects that seem to be pretty much inert, at best.

Speaker cables are capable of making a sonic difference, some of the time.

So now we have TWO problems: the ‘batpoo’ folks making people who like high-resolution music reproduction systems look like loonies, and on top of that, we’ve got this challenge to something that isn’t as nutty as it looks at first glance.

And no matter how this turns out, the folks over at Gizmodo are laughing at anyone silly enough to buy anything more high-fidelity than an iPod. That kind of kills off the next generation of potential aficionados. Which, or course gradually kills off the manufacturers of high-performance gear. So a little bit of excellence goes away.

 

[Gravy]

Oh dear. “Batpoo crazy” might be about right.

That list of moonbeam stuff is embarrassing.

Yeah. I don't mean to paint all audiophiles with that brush. Most people just like good sound and good equipment, without the nonsense. Clark is about as extreme as they come.

 

[pipelineaudio]

Clark is about as extreme as they come.

Sadly, you are just scratching the surface

 

[Inkler]

Sthompson,

I’m aware of ABX testing. It was not a necessary part of what I had to do in my evaluations of equipment. (I’ve just been through a round of discussions on ABX testing on a AV-specialized forum, and I’m kind of tired of the topic, personally. I mean, just worn out on it.)

What I did was not about proving whether or not I could hear, but of evaluating equipment, doing AB comparisons, quite a lot of them blind, but not double-blind. I did this for uncountable hours, for many years. I developed job skills that include an ability to hear quickly what it takes others longer to sort out (maybe) and to hear analytically, so that if something is “off,” I can guess what it is.

Coming at this from an engineering standpoint, as you are, I can see why you want things to be as quantifiable as possible. There are reasons we don’t get better documentation of performance on “spec sheets.” One is that there are “standard” specifications, such as an amplifier’s power rating which is RMS instead of telling you its peak power. Why? Because long ago people rated their amplifiers at the very very tip top of what they could do right before they blew up…. So it was decided that RMS was the “honest” way to rate amplifier power. But is peak capability relevant to performance? Yes. And then, RMS into what impedence? The standard is 8 ohms. Or maybe you can find out what it does at 4 ohms, too. What do real speakers present as a real load to am amplifier? All over the place, not just for any one speaker versus a different design, but within the same speaker at different frequencies. So real world performance of an amplifier is something it pays to evaluate, into actual real speakers; preferably ones you’re considering owning.

On speakers, if people saw how poorly they perform on certain kinds of tests, they’d be shocked. And since those tests tend to produce output data that is very hard to interpret, they would be confusing as well. So people don’t do it.

There’s so much complexity in the performance of a set of speakers alone – let alone what it will do with associated equipment, - that it is easier to just do listening tests than to try to predict what things will sound like from reading even extensive measurements.

Finally, you have the matter of personal taste to consider. You might not like the same things someone else does. There’s no “perfect” so you’re picking your compromise, anyway. My top of the list might be clarity, where you might sacrifice some vocal detail for a bigger wallop in the rear end from the bass. And so on and on and on.

So we evaluate by listening.

 

[pipelineaudio]

Wouldnt you say the reason we use RMS has a lot more to do with that its far more relevant to the way our ears deal with loudness than peak power is?

 

[Inkler]

“Wouldnt you say the reason we use RMS has a lot more to do with that its far more relevant to the way our ears deal with loudness than peak power?”

The way I remember it, there was a legal decision involved, back in the early 1970’s. The government was protecting consumers from misleading claims about “peak power.”

…Since that information is only in my head (and is very old) I decided to poke around for some documentation. I found a whole lot of stuff written about different ways of quoting power, over at Wikipedia, under Audio Power. You may disagree with half the stuff that’s there, in the way of opinion, but agree with the other half, and there’s the part that’s just facts – quoting directly from the law at the top of the page.

Oh, there’s more than I realized.

Legal stuff talks about this:
US market
In the US on May 3, 1974, the Amplifier Rule CFR 16 Part 432 (39 FR 15387) [2] was instated by the Federal Trade Commission (FTC) requiring audio power and distortion ratings for home entertainment equipment to be measured in a defined manner with power stated in RMS terms.

 

[pipelineaudio]

Legal stuff talks about this:
US market
In the US on May 3, 1974, the Amplifier Rule CFR 16 Part 432 (39 FR 15387) [2] was instated by the Federal Trade Commission (FTC) requiring audio power and distortion ratings for home entertainment equipment to be measured in a defined manner with power stated in RMS terms.

There was a more recent similar one regarding car stereos, around 1990

At issue there was so many companies legitamately claiming 1000 watts, illegitamtely claiming the thousand watt amp was ten times as loud as the 100 watt one.

 

[Jeff Corey]

The decibel impaired? Or did it have a setting of "Eleven"?

 

[technoextreme]

this could actually be an easy test for Randi to lose. The test has to be very sensibly thought out.

All theapplicant would have to do is make some awful cables with tons of capacitance and the resultant hi end loss..

He could then go saying "see how "warm" this cable is compared to the "brittle" ones?

This test could end up being pretty tricky to actually pull off

Can someone please answer this question. Why is it that my textbook says to ignore the capacitance/inductance at these low frequencies. It says that a wire is nothing but a wire unless you have 56km of it. Also that would be a simple act of asking for the characteristic impedance of the cable. He might as well get two different cables that have the same characteristic impedance.

 

[danielk]

Why is it that my textbook says to ignore the capacitance/inductance at these low frequencies. It says that a wire is nothing but a wire unless you have 56km of it. Also that would be a simple act of asking for the characteristic impedance of the cable. He might as well get two different cables that have the same characteristic impedance.

I believe the textbook says so because it generally doesn't matter for any practical purpose. But we're talking about audiophiles here.

Some audio website I visited a while ago suggested that instead of buying the snake oil, it might make sense in some situations to make your own speaker wire from common CAT-5 twisted pair cable. This would reduce inductance at the expense of increasing capacitance.

The very informative Cables, Interconnects and Other Stuff pages mention this idea, too.

 

[pipelineaudio]

Can someone please answer this question. Why is it that my textbook says to ignore the capacitance/inductance at these low frequencies. It says that a wire is nothing but a wire unless you have 56km of it. Also that would be a simple act of asking for the characteristic impedance of the cable. He might as well get two different cables that have the same characteristic impedance.

because the textbook is assuming you wouldnt purposefully do something stupid.

I could be wrong but I think there are ways to make problem cables that could make trouble at audio frequencies.

I know for 100% sure that you can make cables too thin, or too assymetrical to work for certain speaker power levels. Any guitarist whos had to use in anstrument cable in a gig because someone forgot the speaker cables can tell you the happy ending on that one.

 

[bjb]

Frequency smearing could be different: even under same frequency response patterns for both cables.

A few questions:

1. What is frequency smearing?

2. How do you measure frequency smearing?

3. Why do speaker cables with the same frequency response have different frequency smearing characteristics?

 

[rsaavedra]

A few questions:

1. What is frequency smearing?

Allegedly the arrival of different (but simultaneous) frequencies at different times at the other end of the cables. Whether it´s exactly that, or whetehr it´s true or not I don´t know, and if true, whether it can be detected by human ears I don´t know either. It´s just something I've seen in audiophile magazines and forums.

2. How do you measure frequency smearing?

I guess with some espectrometers and/or signal analyzers.

3. Why do speaker cables with the same frequency response have different frequency smearing characteristics?

Don´t know either.

Guys, I´m not the guy making claims about frequency smearing. For all I know, it might be just snake oil too. Just bringing it to the table, in a sense giving the benefit of the doubt to audiophiles until conclusive evidence is brought forth about whether frequency response alone could be associated to cables being undistinguishable. Let´s us all beware of hidden assumptions.

 

[Dan O.]

Frequency response is not the only characteristic of a cable. There are also the phase response and various non-linear characteristics. A dialectic with non-linear properties would cause harmonic distortion. Frequency dependent propagation velocities would produce what was probably referred to earlier as "frequency smearing".

These characteristics are real and measurable when dealing with very high frequencies, high power or long cables. I can't imagine even a cheap cable not having a perfectly flat response at audio frequencies and only a few feet between the amp and speakers.