Those who own Audioquest cable...what do you think?

[mansr]

This is a slippery-slope. Most electronics engineers will scoff loudly and long at the notion that one USB cable is any different from another as long as it meets all the USB specs as put forth by the IEEE. I am of this opinion also. However, I must, in all honesty, say that while I can't see what could possibly affect a USB signal enough to change the sound, as long as the cable met specifications, I also cannot simply discount the empirical evidence of people here, who I trust are not either lying or imagining things when they say that they consistently hear a difference between one USB cable and another.

 

It's the emperor's new clothes.

[mansr]

Which ones work like filters? Most of the cables I see clearly show the type of conductor they use, and its unbroken from connector to connector. Are you sure that you're not talking about shielding?

 

An inductor also has an unbroken conductor running end to end. Every cable can be modelled as an equivalent network of perfect resistors, inductors, and capacitors, aka a filter. An ideal cable has zero resistance, inductance, and capacitance. In reality, while resistance is easy to make arbitrarily low (use thicker wire), there will always be some inductance and capacitance although any competently designed cable should have values low enough not to affect the audio band noticeably.

[mansr]

Except that at audio frequencies, these reactive characteristics of which you speak are negligible. Reactive losses that are huge at frequencies of 100 MHz or higher, are minuscule and have no measurable effect at 20 KHz or below. Perhaps there is something going on that we don't know how to quantify or measure, and that's always a possibility. But until such time as those characteristics come to light, there seems to be nothing in the science of electronics that would, in any way, explain the phenomenon of interconnect cable sound.

 

If such unknown effects exist, one would expect them to manifest in other places than audio cables.

[mansr]

Yet, I cannot, in good faith, just write-off those here who are 100% sure that interconnects can alter the sound of their stereo systems.

 

I can, and I do.

[mansr]

Taking a pill you expect to make you better and instead feeling worse is still placebo. There was no reason for it yet a perceived change occurred. It has been called nocebo. That term is used both for negative reactions to expected good from a sham treatment, and negative reactions to something containing a warning that it may have negative side effects.

 

So just because fancy and expensive cables are heard as worse or not better doesn't change the basic mechanism. If nothing else experiencing a difference where one doesn't exist whether good or bad whether according to expectations or contrary to them is a similar effect.

 

If the expensive cable fails to deliver the expected improvement, it could easily be perceived as worse than the cheaper one it replaced, even if there was in fact no change at all.

[mansr]

It’s music that is special and magical. Audio equipment and cables are used to reproduce music. We just want that magic in our listening rooms, we let others worry about physics, music is the important thing.

 

The signal in the jet or Mars rover doesn’t need to image well, doesn’t need warm, full and powerful bass, doesn’t need an accurate midrange, doesn’t need smooth beautiful high frequencies, doesn’t need convincing ambiance, etc.

 

Simple, those types of signals don’t reproduce music. If the signals that operate complex machinery sound terrible it would not effect their operation at all.

 

You evidently know nothing whatsoever about electronics, music related or not.

 

By the way, you still haven't told me why your portrait in your avatar is colored blue.

 

The lighting was blue.

[mansr]

But is this so?

 

I ask because science clearly knows that music is defined by just two variables; amplitude and frequency. We have instruments that can measure both to levels that far exceed the limits of what humans can discern. Instruments can also measure other distortions, such as noise and phase irregularities, with similar accuracy levels.

 

I guess what I am wondering is what distortions is science not measuring that the brain might be interpreting?

 

The distortions added by the brain itself are hard or impossible to measure.

[mansr]

Music is defined by far more than two variables. (Yes, I am speaking scientifically.)

 

Regarding our hearing (the entire auditory system, including the relevant areas in the brain), what it is exquisitely good at (and has in fact been drafted into scientific research regarding), far better than any computer or measuring device yet invented, is pattern identification and matching. See generally the articles quoted and cited at http://www.computeraudiophile.com/f7-disk-storage-music-library-storage/does-zip-or-tar-gzip-archive-compression-damage-audio-files-26390/index10.html#post482948.

 

The human brain is indeed incredibly good at certain kinds of pattern matching. However, the brain is so intent on finding patterns that it is very prone to false positives, e.g. seeing faces in clouds. The patterns it detects are also dependent on a huge number of external influences such as environment, mood, and various physiological states, all of which are difficult or impossible to control or compensate for in a test. All this makes subjective experience a rather poor tool in evaluating the performance of a mundane object like a cable.

 

Of course when it comes to music itself, the subjective experience is all that matters. If I say Beethoven's 7th is better than his 4th, you may disagree, but there is no ultimate right or wrong answer.

[mansr]

If we are talking about "music" rather than "a signal," in my view this presupposes a listener and thus the brain's processing would not be a distortion.

 

Wrt a "signal," yes, a great deal of what comes out of our speakers gets turned into something else by our brains. We in fact depend on many of these "distortions," such as the brain conjuring a single image from two signals coming out of two speakers, or attributing not only a base frequency but an entire series of harmonics to a single instrument or voice.

 

True, but we're mainly concerned with ensuring the signal that enters the ears is as close to some ideal as possible. This is something we can measure.

[mansr]

What, besides amplitude and frequency, defines a waveform?

 

Phase.

[mansr]

In the case of the devices being talked about in the OP, we can measure the distortions and reference them to known limits of human distortion thresholds. Or, are you saying that we don't know what those limits are?

 

Even with perfectly identical inputs, the brain doesn't always see or hear the same thing. We cannot presently measure what someone actually heard.

[mansr]

We can measure the amplitude and frequency errors of electrical signals and compare them to known limits of human hearing. Unless you are saying that we don't know what these limits are?

 

That is not what I'm saying. I was addressing the "music is so much more than a waveform" comments.

[mansr]

As mansr said, phase. And as regards "properly designed," phase changes are part of the design of the filters used in many DACs. But that is just as regards waveforms, not music. With regard to music, there is timbre, which consists of many things. Some academic papers recognize upwards of 20 aspects of timbre. The most commonly included aspects are harmonics/overtones, and characteristic attack/sustain/release. There are also time-related aspects, such as rhythm and meter.

 

All of those are fully described by a Fourier transform as a collection of frequencies of various amplitudes and phases. The higher-level concepts like timbre are useful when discussing music and musical instruments, but DACs and amps don't care about such things.

[mansr]

Odd, then, that there are academic papers dealing with trying to adequately model such aspects of timbre as inharmonic attack transients in digital audio.

 

That's useful for analysis or synthesis of music signals, such as in a lossy compression scheme. It has no bearing on reproducing a recorded waveform other than perhaps as a tool to assess the impact of measured imperfections in the reproduction.

[mansr]

Think of an analogy to another sense, sight. Certainly aspects of the signal are well modeled and understood. But it was quite a long time until we knew enough to make CGI of the complex variations of light on hair, the appearance of a mountain, or the play of emotions on a human face look real.

 

That's a flawed analogy. If you want a visual counterpart to hifi audio, you should be thinking of photography (or videography). CGI would be akin to completely synthetic sounds, and accurately mimicking a real musical instrument is indeed very hard.

[mansr]

Why would that be, if we understood what creates a sense of "reality" in audio?

 

Understanding something doesn't necessarily make it easy. We understand how atomic fusion works, but there are still no reactors to be found. Also, I never said we fully understand "what creates a sense of reality."

[mansr]

For both those reasons, particularly the latter one, it is difficult to be sure we are measuring the right things, or measuring them with adequate accuracy.

 

If two waveforms are identical within the accuracy of our best test equipment, they will sound the same. If one sounds real, so will the other, doesn't matter why.

[mansr]

OK, I'll take you up on that. Why is it that a caricature, cartoon, or drawing of a person can elicit from us an emotional response reminiscent of seeing the real human being it represents, while a computer-generated facsimile objectively closer in every visual detail can cause us to inwardly exclaim "There's something not right about this!" (Akin to the feeling of seeing someone who's had plastic surgery - something subtly, irritatingly wrong....)

 

I don't have an answer to that, but I also don't think it matters to the topic at hand. With an audio cable, we can measure what goes in one end and what comes out the other. If there is no detectable difference, there will be no effect on the sound either.

 

Is there any analogy to be drawn to LPs versus digital?

 

I don't think so.

[mansr]

Not necessarily so, if one is not testing for the right things, where "the right things" can be quite prosaic;

 

If the amplitude vs time is identical anything else you choose to measure must also be identical.

 

and if neither sounds very real, what good does identical performance do?

 

That just means the input signal didn't sound real to begin with, and that's not the fault of the cable being tested.

[mansr]

I understand that the cryogenic treatment is done to bare wire, before any insulation or jacket is installed. If such is the case, people can draw their own conclusions about the individual's 'expertise'.

 

Maybe some do, but then the third point kicks in. There are also companies that will freeze whatever cables or even entire amps you send them.

[mansr]

BUT, I do hear meaningful differences between cables, often unrelated to cost and usually in terms of attenuation or emphasis of particular frequency ranges.

 

So, for the "measureholics" what do you believe to be things that could validly affect sound quality? Let's leave out cable thickness for the moment, but shielding, material, material purity, stranding, flat versus round, single versus multiple strand, are all legitimate parameters.

 

Three letters: L, C, R

[mansr]

ok. that is a trivial and uninformative answer.

 

are you saying that two cables with the same LCR will sound identical?

 

Yes. How could they not?

 

can you predict how the sound from a system changes when you perturb one of these parameters?

 

Assuming the change is large enough to make a notable change, the exact result will additionally depend on the characteristics of the source and load. Although those are more complex, if they are known, the overall response can be calculated.

 

how do differences in LCR (bulk and surface) translate to differences in the sound signature and sound quality, particularly in regard to "sounds better"?

 

Objectively, a "better" cable is one with a flatter frequency response. Subjectively, a given individual may have a preference for just about anything, and that is impossible to predict.

 

how does one measure and characterize properties of cables (and other things) in a way that allows for the proper evaluation and production of components for improved sound without the voodoo BS that is so common?

 

Using standard test equipment and methods covered in any 1st-year electronics course.

[mansr]

could you tell me what the ideal values of LCR are for flat frequency response?

 

Zero.

[mansr]

Yeah, but where is the data that tells you how it sounds? LOL

 

The quoted data tells you that it has no discernible effect on audio frequencies.

[mansr]

Off the top of my head: if one has better shielding in a high-RFI environment; OTOH, in cables where noise resulting from crosstalk is a concern but there is low RFI, effective separation of conductors might result in better sound, compared to a heavily shielded cable that keeps the conductors in close proximity.

 

You can hear radio frequencies?