High-end audio cables

From Wikipedia, the free encyclopedia

This article has been nominated to be checked for its neutrality. Discussion of this nomination can be found on the talk page. (December 2007)

High-end audio cables are claimed to improve the sound quality of high-fidelity audio systems but whether they actually do is hotly disputed. Since the audio signal passes through cables on its way from the source to the amplifier, or from the amplifier to the speakers, the cables will affect that signal. Whether or not affects are measurable and/or audible remains a question. Cables between components are called interconnects. Speaker wires carry the signal between the amplifier and speakers.

For analog cables Basic system frequency response can be calculated from the electrical properties of the cables, and components on either side of the cables. These electrical properties include resistance, capacitance, and inductance. For small-signal applications the degree of shielding is also important. All of these qualities are taken into account in the design of commercial and broadcast cables. High-end cables for the audiophile market often involve intricate construction geometries and exotic materials such as silver and oxygen-free, long-crystal, high-purity copper.

Digital cables, such as TOSLINK, coaxial and HDMI, are less vulnerable to signal degradation for the short lengths used in consumer audio which makes audiophile claims harder to measure.

Contents 1 Controversy 1.1 Digital cables 1.2 Speaker cables 1.3 Mains power cables 2 See also 3 References 4 External links

[edit] Controversy

There is controversy among audiophiles surrounding the impact that high-end cables have on audio systems. The audibility of the changes is a matter of much debate. There are claims that, even among audiophiles, in a double-blind test it is difficult or impossible to distinguish extremely expensive, exotic speaker cables from ordinary lamp cords or budget 12AWG copper speaker wire.^[1][2]

James Randi, a stage magician and scientific skeptic best known as a challenger of paranormal claims and pseudoscience, offered a prize of one million dollars to anyone who could prove his or her ability to distinguish an expensive high-end audio cable from an ordinary audio cable by means of a controlled listening test. ^{[3] [4]} Michael Fremer of the Stereophile magazine took the challenge, but satisfactory testing conditions could not be agreed upon, and the test did not take place.^[5] In rigorous tests performed under controlled circumstances listeners have not been able to prove there is any audible difference between high end and cheap cables^[6].

[edit] Digital cables

One of the more contentious areas is in digital cable design, with high end cables being sold with claims of "distortion-free signal transfer." Some have argued that since the bit rates (approximately 1 Mbit/s) and distance traveled are considerably lower than for other data transfer technologies such as gigabit ethernet, any cable appropriately matched to the correct impedance requirement is sufficient. Others claim that jitter caused by imperfect impedance matching is very detrimental to the audio signal and the most substantial shortcoming of digital audio. This has led equipment manufacturers to design new standards such as I²S which separates clock and data signals or implement buffering and reclocking, although such standards are typically aimed at synchronising multiple signals to a single clock rather than attempting to correct errors due to jitter.

[edit] Speaker cables

Another area of debate is speaker cables. Skeptics say that a few meters of cable from the power amplifier to the binding posts of the loudspeakers cannot possibly have much influence because of the complex crossover circuits found in most speakers and particularly speaker driver voice coils with several meters of wire.

A global concern with speaker cables is their inherent impedance relative to the impedance of the loudspeaker. Low impedance speakers are claimed to benefit most from low impedance cabling; this means thicker and/or shorter wires. It is claimed that longer cable runs need to be even thicker to minimize signal loss.^[7]

Roger Russell – a former engineer and speaker designer for McIntosh Labs – details how expensive speaker wire brand marketing misinforms consumers in his online essay called Speaker Wire - A History. He writes, "The industry has now reached the point where [wire] resistance and listening quality are not the issues any more, although listening claims may still be made....The strategy in selling these products is, in part, to appeal to those who are looking to impress others with something unique and expensive."^[1]

[edit] Mains power cables

Another controversial area of audio cabling is that of mains power cables. Products exist that claim to improve the sound or picture with a short length of expensive oxygen-free copper or silver cable connected from the wall socket to the equipment.^[8]. More scientific arguments have been presented, such as building RFI (Radio Frequency Interference) filters into the cables as well as shielding against EMI (Electro-Magnetic Interference) can produce a cleaner noise free supply and hence a better sound or picture quality ^[9]. Although subjective tests have occasionally confirmed this, little objective proof has been given.^[10] One critique of high end power cable questions how a short strand of expensive cable can improve upon electricity delivered by miles of standard electricity transission equipment outside and inside a home. Given this paradox, he then asks, "how short does the [specialized] wire have to be made before differences can no longer be heard?"^[1]

[edit] See also

• S/PDIF A digital audio interconnect standard
• DAC Digital to analog converters
• Clock recovery on handling of digital data streams
• Speaker wire
• Psychoacoustics on the perception of sound
• Subject-expectancy effect on the possible causes of perceived differences attributable to cables

[edit] References

[edit] External links

• Solving Signal Problems - Belden Corp article for Broadcast Engineering magazine
• Speaker Wire - Roger Russell (former McIntosh Laboratory loudspeaker designer) opinions on loudspeaker wiring