AudioQuest

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AudioQuest, founded in 1980 by William E. Low, is a manufacturer of audio/video cables, digital-to-analog converters, headphones, power-conditioning products, and various audio/video accessories—all claimed to match high levels of performance and sold at high prices.

AudioQuest is based in Irvine, California, has offices in the Netherlands and distributes its products to approximately 65 countries throughout the world.[1]

History[edit]

AudioQuest's founder, William E. Low, has described himself as "an absolute hedonist." In the December 2008 issue of The Absolute Sound, Low explained to TAS’s Neil Gader, "Everything I’ve learned about hi-fi or cables is purely the result of being interested in getting high on music."[2]

In his early days of selling high-end audio equipment, William E. Low discovered that the sound of an audio system was easily influenced by the quality of the cables connecting its various components. Hi-fi journalist, Richard Hardesty explained:

"With experimentation Bill found that better interconnect and speaker cables could make bigger audible improvements than many costly upgrades to amplifiers and speakers. And he recognized the opportunities afforded by this new category of audio components. He founded AudioQuest to explore and develop new and innovative wire, connectors and accessories."[3]

Although AudioQuest remains best known for its analog and digital cables, the company has entered other product categories, such as the DragonFly USB digital-to-analog converter/headphone amplifier, recipient of numerous awards, including: Stereophile 's 2012 "Computer Audio Component of the Year"[4] and 2012 "Budget Component of the Year;"[5] Tone Audio 's 2012 "Digital Product of the Year;"[6] Computer Audiophile's 2012 "Computer Audiophile Product of the Year;"[7] AudioStream's "Greatest Bits",[8] and What Hi-Fi?'s 2014 "Product of the Year."[9]

At the 2015 Consumer Electronics Show, AudioQuest entered the headphone market with its NightHawk over-the-ear headphones designed by Skylar Gray. In October 2014, NightHawk was named 2015 CES Innovation Award Honoree (Headphones) and 2015 Best of Innovation Winner (Eco-Design and Sustainable Technologies).[10] The NightHawk was followed by the critically successful NightOwl headphone and a headphone stand called Perch.

Ethernet cable evaluation[edit]

AudioQuest sells Ethernet cables that they claim are "directional". While this "one of a kind" strange concept of directional Ethernet cable is fundamentally wrong and goes against very basic technical principles in digital electronics of the Ethernet standard IEEE 802.3 :[11] One independent blinded ABX test of the ethernet cables at The Amazing Meeting in 2015 found that the cables do not produce a measurable effect. Independent physical testing of the data transmission quality of AudioQuest's ethernet cables claimed to show they perform no better than class compliant cables costing less than 1/10 the price due to the near-end crosstalk. Although admitted in the article they weren't equipped to test cat 7 cables and instead tested the cable to the lower cat 6a spec. Also shown in one area the AQ cable bested all other cables at the limit of cat 6 testing/ standard speed of 500 MHz while unable to show a possible higher cat 7 standard of 600 MHz due to lower limit of 500 MHz on the cat 6a standard test.[12] There is some controversy in the audio industry as to whether or not cables make a difference in the sound of a system.

Effects of cable quality on analog audio quality[edit]

There are two distinct domains where the physical attributes of analog electrical cables can affect the quality of audio reproduction:

1) Noise and crosstalk: All electrical conductors exposed to ambient electromagnetic fields are susceptible to picking up external electrical interference from the environment, in particular when weak analog signals are involved. This type of interference is often experienced as "hum" (60 Hz/50 Hz power line frequency), hiss (cosmic/ atmospheric noise), clicks and pops from current spikes generated by nearby man made electrical devices or digital noise from nearby computers.

While ambient electrical noise is a serious issue when dealing with millivolt and microvolt signals such as those typically originating from microphones and other input transducers, it is highly unlikely that such induced noise would significantly audibly affect high level output signals in low impedance systems such as the speaker wires connecting an amplifier to a speaker, unless of course, the cables are unusually long, the location is unusually noisy or the listener has an exceptionally good ear.

The best way to reduce the inclusion of electrical noise is two twist the conductors together, use shielded cables, employ differential drive or a combination of all three methods. Also, the cable interconnect keep should always be kept as short as physically possible.

Electrostatic and piezoelectric noise can also become an issue in exotic headphone systems, if the headphones have a relatively high input impedance compared to traditional speakers which have a nominal impedance of 8 Ohms. This is where a careful choice of insulating materials can make a difference. This type of noise is often perceived as snap, crackle and pop when mechanically manipulating or handling the headphone cord. It is often hard to tell, without actual measurements if the source of this noise is electronic or mechanical in nature.

2) Impedance: Low impedance speaker systems (typically 4-8 Ohms) operating at high power draw heavy currents. A 100W RMS, 4 Ohm speaker operating at full power, for example requires a current of 5A RMS. Depending the length of the speaker cable, and the listener's budget, a minimum wire size of 16AWG is required, and stranded copper cables as heavy as 12AWG are recommended.

Unlike simple power distribution systems, cable overheating in audio distribution is not the only consideration. If the cables are too long or too thin, significant power is lost within the cable, due to the lower load impedance. The music may lack punch and the system's damping factor/transient response may be adversely effected. As the cable ages, individual strands may also brake or loose connection due to oxidation.

The sound pressure level produced by an audio system, the thing we perceive as loudness, is the result of instantaneous air pressure = force per unit area, which is proportional to the speaker cone acceleration/air mass density, which in turn is proportional to the squares of the speaker size, signal amplitude and signal frequency (angular velocity). When a speaker cone is driven by an electrical voltage, the resulting current produces a magnetic field, causing a magnetic force to accelerate the speaker cone, generating sound pressure... etc.

In this scenario the speaker cone acts as a linear motor, accelerating the air in front of it and creating vacuum behind it. Once the speaker cone is in motion, it has inertia and wants to remain in motion opposed only by the air pressure difference in front vs behind the cone. If the moving cone were to be disconnected from the amplifier at this point, it would over shoot its desired destination causing "ringing" and transient distortion. The reason it that does not do that in the extreme, is that the moving cone is also acting as a generator with the amplifier acting as a short-circuit across the generator, in effect putting the brakes on excessive speaker excursion.

The ability of the amplifier to "dampen" this cone inertia effect is sometimes called the "damping factor" of the amplifier and it is related to the inverse of its output impedance.

Expensive audio amplifiers have ultra low output impedance and very high damping factors in order to yield low distortion/ accurate transient response audio with crisp percussion and brass music reproduction in jazz recordings, for example.

Using an under-rated, long, skinny, oxidized high impedance speaker cable will drastically reduce the damping properties of the entire audio system, which is why in many high-end audio systems, the amplifier is located as close to the speakers as possible.

Oxidation: Aging cables exposed to air will oxidize, increasing impedance, causing intermittent connectivity and poor shielding, all of which will adversely effect the reproduced audio quality. Many plastic insulation materials composed of halogenated hydrocarbons decompose with age, releasing corrosive gas such as Chlorine, Fluorine, Oxygen etc. Quality cables are less prone to this.

Having said all of the above, there is little scientific or engineering evidence (if any) that most of the inflated claims of "material and processing magic" advertised by companies like AudioQuest or Acoustic Research in promotion of their untypically expensive cable products has any merit on final audio reproduction quality.

Criticisms[edit]

Directional cables and other snake oil.

There seems to be little scientific evidence or underlying scientific foundation to argue that audio cables (or any other electrical cable) have directional properties, certainly not at normal audio frequencies. Audio cables are not semiconductors, they are made of materials with bulk properties where semiconductor or quantum effects do not apply. Indeed, within the mainstream engineering and scientific community, notwithstanding the metaphysical, most of these claims appear to be absurd. Indeed many of these supernatural claims of cable superiority detract from what otherwise would be high quality, reputable products made by the same companies.

The only plausible directional effects would be in areas of cable shielding, termination, physical connectors and termination impedance, where a highly specific cable could be engineered to be used in a particular direction, grounded or terminated at only one end, etc.

Effects of cable quality on digital audio quality[edit]

Audio transmission in the digital domain is vastly different from analog system. Any signal degradation due to lack of cable quality can only effect the transmitted information at the digital coding level.

1) If the cable is "good enough" to fully recover the digital data stream, no matter how badly the carrier signal was degraded during the transmission, the audio quality will be unaffected.

2) If on the other hand, the digital signal is damaged so bad that the original audio information cannot be recovered, no audio will be received.

3) If the cable or transmission channel is marginal, the resulting digital errors will either:

a) Be transparently corrected using redundant data and forward correction techniques.

b) Be detected causing retransmission requests, communication slow down and delays

c) Be ignored causing clicks and dropouts in the audio.

4) Nanosecond delays and propagation velocity within digital cables will have no effect on audio perception. Frequency response of digital cables will have no effect on audio quality, unless the cable is so bad that it causes data errors. Frequency response of HDMI cables, for example, may affect the maximum data rate and thus the maximum resolution of video signals, but it will have no impact on any encoded audio if the cable is at all functional. The same is true for Ethernet cables.

Therefore, the only signal degradation possible, which could actually effect audio quality would be that which causes severe transmission error rates and/or digitally unrecoverable errors. Poor frequency response, poor shielding, inconsistent cable impedance, standing wave reflections, high DB loss over longer distances, high propagation delay causing handshake failures, could all theoretically all cause such errors.

Any undamaged, correctly designed and manufactured digital cable system operating within its specifications and within the envelope of its specified environment should not experience error rates outside of the limits of the digital system's ability to correct or handle them in an acceptable way. As long as the foregoing is true, the cable price or alleged quality will have zero effect on the quality of audio decoded from the digital stream.

See also[edit]

References[edit]

  1. ^ "3 Questions for Bill Low (Fidelity Magazine)". YouTube.com. Retrieved 29 December 2014.
  2. ^ The Absolute Sound, December 2008, "9 Questions for William E. Low, Founder, CEO & Designer, AudioQuest" by Neil Gader
  3. ^ "An interview with William Low" (PDF). Auriclepublishing.com. Retrieved 29 December 2014.[permanent dead link]
  4. ^ "Stereophile's Products of 2012 Computer Audio Component of the Year". Stereophile.com. Retrieved 29 December 2014.
  5. ^ "Stereophile's Products of 2012 Budget Component of the Year". Stereophile.com. Retrieved 29 December 2014.
  6. ^ "Tone" (PDF). Tonepublications.com. Retrieved 29 December 2014.
  7. ^ "Computer Audiophile - 2012 Computer Audiophile Product of the Year". Computeraudiophile.com. Archived from the original on 2014-12-26. Retrieved 29 December 2014.
  8. ^ "AudioQuest Dragonfly v1.2 USB Digital-Audio Converter". Audiostream.com. Retrieved 29 December 2014.
  9. ^ "Best DACs 2014 - What Hi-Fi? Awards 2014". Whathifi.com. Retrieved 29 December 2014.
  10. ^ "AudioQuest Named as 2015 CES Innovation Awards Honoree & 2015 Best of". Prnewswire.com. 18 November 2014. Retrieved 29 December 2014.
  11. ^ "The audiophile's dilemma: strangers can't identify $340 cables, either [Updated]". Ars Technica.
  12. ^ "Expert electrical analysis: $340 audiophile cables test "marginal"". Ars Technica.