Talk:High-end audio cable

"Common" engineering calculations done with the use of computers since the 1980s can handle foumulae with the terms which become important at frequencies above 100Hz. The formulae for alternating circuits [by Maxwell] have been around since 1890s.

A big problem is describing the circuit, impossible for a nonshielded cable. Another is knowing the alternating current properties of the insulations and of the commonly used braid shields.

It seems to this retired electrical engineer, with 10 years of cable installation and application experience, that the rest of the playback equipment is more important than the cables; especially the position of the listener in a given room, and the physical qualities of that room.

All recordings have had many physical limitations imposed. One can not recover data which has been discarded! The number of inputs [usually microphones], the placement of those inputs with respect to the sound source, the quality of the recording equipment, the skill of the "mixing" of inputs are critical. The person running the mixing board many times puts too much emphasis on one input, eg: the piano, which causes unremoveable distortion from the given recording.

I urge having someone with excellent hearing to judge a room and its associated playback equipment to listen to the playback of some recorded music which that person has heard during a "live" preformance, preferably during the recording of that music. After all, what is desired is having music played back without distortion of the original quality.

Missing from most of these is the fact that the shield should be connected ONLY at the source end to prevent circulating currents in the shields! This fact is well established in circuits involving critical measurements.

I believe this statement should be detailed to avoid confusion. In some cases connecting the shield only the source end can be much worse then connecting both ends, or none.

For unbalanced connections, since the shield also carries signal, both ends *must* be connected. Doing otherwise will be very noisy at best.

http://www.epanorama.net/documents/groundloop/ for more details

Needs clarification + digital

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.

Article Must Move Towards Fact Based Content

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.

Intro

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 analsis will tell you.