Talk:High-end audio cable

message: The article claims: 
: However, since most modern DACs buffer the signal to some extent and the data recovery clock does not directly drive the DAC clock, data jitter rarely has any effect on the final output as long as it does not cause data corruption
This second part of this sentence is incorrect. The DAC clock has to go at the same rate as the data recovery clock, and so the DAC clock is phase locked to the data clock. The PLL acts as a low-pass filter, potentially changing the spectral profile of the jitter, but it does NOT bring it to a negligible level. 
When you're looking at source of distortion for a high quality audio DAC, clock jitter is one of the dominant ones. The right architecture would be that there is a high-quality crystal oscillator at the DAC, and that clock is then transmitted to the source. This would have both measurably better performance (and, most likely, audibly better performance). With the clock at the source, clock quality, clock transmission quality, and clock recovery loop design all have impact on overall performance. 
I do not mean to imply that magical fancy cables will have any impact here (beyond shielding and having proper line impedance, not much matters for digital transmission lines). But the argument as stated is incorrect.   —Preceding unsigned comment added by 24.128.191.214 (talk) 11:29, 27 April 2011 (UTC)
thread_title: Clock jitter

message: I have a problem with this part taken from the Cable theory section:
In his 2001 master’s thesis, “A New Methodology for Audio Frequency Power Amplifier Testing Based on Psychoacoustic Data that Better Correlates with Sound Quality”, Daniel Cheever points out a number of flaws in conventional testing that indicate the ear is extremely sensitive to tiny signals well above the normally-expected range of human hearing. The high-order harmonics to which he refers exert an influence on our perception of the sound that is vastly disproportionate to their strength, to the point that research from as far back as 1937 indicates that high-order harmonics may actually exceed the subjective effect of their lower-order cousins.
It sounds as if the citation to the thesis is a citation from the thesis itself to earlier (the 1937) research. Surely it would be more helpful to reference the 1937 research?
Since higher-order harmonics can be of much higher frequency and much lower amplitude than normal audio measurements measure, they provide one explanation for the apparent insufficiency of conventional electrical engineering theory in explaining the influence of high-end audio cables. Since this is but one theory, though, it is important that the reader familiarize himself or herself with the basics of audio measurement.
Tests I've seen for harmonic distortion resolve as low as -100 dB, where 0 dB is the test tone intensity. This should be possible with good quality testing equipment. It would be helpful if a figure is given for the amplitudes of these higher order harmonics, and whether or not these amplitudes are audible to the human ear. The 'higher frequency' part also needs clarification. Usually tests are conducted across the full audio bandwidth, 20 Hz to 20 kHz, and with high quality equipment it should be possible to cover an even greater range. Audio equipment is usually limited, either by design or through performance limitations, to roll-off frequencies above 20 kHz. Therefore, the average (analogue) audio cable won't be carrying anything important in the above 20 kHz range.
The article could mention digital audio cables separately, as these carry signals quite different to the normal analogue ones, requiring different designs.
It would be informative to talk about the electronic differences in a signal transmitted by a high end audio cable and a low end one. Any differences (if they exist) would certainly be detectable by machinery even if not by the human ear. I have a basic understanding of analouge signals and how they relate to sound, but this article's treatment of the electronic aspects of signals is superficial. It only talks about the audio. What I would like to see answered is, "How does an analogue signal change as it is transmitted over an audio cable?" I also agree that digital audio cables should be treated separately. 
In response to the comments on the masters thesis, I believe that this research is a little cutting edge for wikipedia. I dont believe that wikipedia should present research that the scientific community has not reached at least some consensus on. Maybe the article should simply say, "It is unclear how much slight changes in sounds affect our perceptions of sounds." Marcusyoder 02:23, 23 September 2007 (UTC)
thread_title:  Needs clarification + digital 

message: Removed some sections that exhibited unsubstantiated bias against high-end audio cables and replaced them with fact based information.  Naysayers must provide evidence of their claims if they are to remain in this article.  The frequency response plot link that was added is a powerful example of how electrical engineering predicts the changes that cables will make.  Capacitance Inductance and Resistance are not mysteries.  They provide solid evidence of the SOME of the differences that cables will make. —Preceding unsigned comment added by Apblake (talk • contribs) 
:Of course those parameters have an effect on the signal. But, a) are those effects relevant at audio frecuencies, levels, and usual runs of cable? I'd say no for most systems, as long as you use an adequate gauge size of even cheap cord. And b) you can buy inexpensive cable with low capacitance, inductance or resistance from known providers that has nothing to envy (but the prize) to high-end cables in this respect.--80.24.18.223 (talk) 13:33, 27 May 2008 (UTC)
thread_title:  Article Must Move Towards Fact Based Content 

message: There are a few important points that should be conveyed in the intro without going into too much detail.  For starters, there is controversy over the audibility of the differences that cables have.  It is also very important to say that basic electrical parameters such as resistance, capacitance, inductance, and conductance will have an effect on the signal, but that they are by no means the only influence.  Many people falsely believe that these factors are the only things that influence the signal when science clearly predicts a variety of other phenomena.  It is not appropriate to include a long winded explanation of all of these phenomena in the intro, but it is important to let people know that the problem is more complex than what a simple lumped circuit analysis will tell you. —Preceding unsigned comment added by Apblake (talk • contribs) 
:The comment above appears to be from a purveyor of seven thousand-dollar audio cables.  —Preceding unsigned comment added by 24.6.157.14 (talk) 21:32, 26 October 2007 (UTC)
replies: text:  It would be nice if he could elaborate about these other effects and what is the relative influence of these effects to the audio signal that the cables carry.--80.24.18.223 (talk) 13:38, 27 May 2008 (UTC)
thread_title:  Intro 

message: Guys, the triboelectric effect is the effect whereby dissimilar materials in contact will pick up a charge - like wool and amber. But it's static electricity, so it will drain instantly out of any cable that's just sitting there. The only way it's going to make a difference is if A) the cable is so poorly constructed that dissimilar materials are actually rattling around inside it B) the cable is physically being moved around while you're listening, causing these dissimilar materials to come in and out of contact. You would get a pop/crackling noise. Unless I'm missing something really obvious, this is a howlingly ridiculous claim, and I'm rather shocked that it's been in the lede for several months... <eleland/talkedits> 18:59, 15 June 2008 (UTC)
thread_title:  Tribolectic effect? Rofl. 

message: The article currently mostly speculates, and discusses artist type tests. It would be more useufl to base it on sound engineering principles to show that
# cable choice does affect sound
# to an extent that is utterly insignificant, unless extremely long runs are used
86.4.152.167 (talk) 12:21, 26 January 2009 (UTC)
thread_title:  science or art 

message: This page has no section on line-level analogue interconnect.  In parts it looks like it's all about speaker cable (which would make it a badly-named article), but it includes sections on digital interconnect and mains cabling.  What's it really about?  --ToobMug (talk) 02:17, 5 January 2010 (UTC)
thread_title:  Missing section 

message: The article states that HDMI uses error correction.  Error correction is only used in the data portion of the HDMI signal.  The video and audio portions do not have error correction.  You can read through 5.4.4 of the 1.3 spec for video and 7.7 for audio.
http://www.hdmi.org/download/HDMI_Spec_1.3_GM1.pdf  —Preceding unsigned comment added by 68.104.183.6 (talk) 04:09, 3 January 2011 (UTC)
replies: text: However, that statement 
"Cables carrying digital signals, such as S/PDIF and HDMI, are effectively immune to signal degradation for the short lengths used in consumer audio."
in itself might not be exactly true. One one hand, it might very well happen that (either in household or office or outdoor use) one might want to use a cable several (or even a few) meters long; or a cable that is not-very-well-made (contact fault etc) or an unshielded cable in an environment with large EM noise (near a transformer or electric machines) and if the SNR goes too low, digital stuff won't help anymore. (See USB - also can't do even a few meters). Hoemaco (talk) 12:06, 2 June 2011 (UTC)
thread_title:  HDMI Standard