Audio Interconnect and Speaker Cable Myths and Facts Revealed

The audio industry has its share of marketing nonsense, especially when dealing with the topic of speaker cables and audio interconnects.  In this interview, Hugo Rivera (VP Marketing of Audioholics) asks Gene DellaSala (President of Audioholics.com) to discuss some of these common myths and to also give general advice when shopping for audio cables.  We discuss everything from speaker cables to audio interconnects.

Check out our two-part YouTube video interview as it covers material not included in the written interview below.  We even show some examples of inexpensive and spendy snake oil free speaker cables and terminations that will meet your needs.

Audio Cable One-On-One Interview with Gene DellaSala (left) and Hugo Rivera (right)

Hugo: Gene please tell us why there are so many crazy myths surrounding speaker and audio cables?

Gene:  Exotic Cable companies often take advantage of the fact that the vast majority of audiophiles and professional reviewers do not have a degree in electrical engineering. While you don’t need an electrical engineering degree to enjoy this hobby, it allows you to tell the difference between real science and pseudo-science, between reality and myth, in this industry. Pseudo-science is taking a grounded and provable scientific principle but manipulating it into a nonsensical form that is not verifiable.

The common audiophile is constantly and desperately looking for ways to improve and tweak the fidelity of their audio systems, and they want to believe in the promise of groundbreaking improvements, even when they are not scientifically sound.  Thus, the power of suggestion is very strong and many exotic cable manufacturers know this all too well.  As you know, this isn’t dissimilar to the workout supplements industry.

Electronics and Electrical Engineering theory is often intimidating to untrained individuals, similar to how bodybuilding may be intimidating to someone that has never worked out with weights before.

What many exotic cable manufacturers do is start off with a real engineering premise and stretch them beyond what would even be considered believable as Star Trek physics, hence the pseudoscience is born.  Some of their theories are even more cockeyed than a looney tunes episode in that they don’t even correctly identify how the phenomenon works. 

Hugo: Can you list some of the common pseudoscience and misconceptions?

Gene: One of the biggest misconceptions exotic cable vendors like to perpetuate is a problem with “skin effect”.  Simply put, skin effect is a measure of how the resistance and inductance changes in a cable as a function of frequency.  As frequency goes up, the skin depth decreases along the conductor, so in a sense the conductor becomes less conductive at those frequencies since the higher frequency currents are mostly distributed towards the surface of the conductor.  The reality of the situation is that even common 12 AWG speaker wire still has VERY low resistance at almost 1/2 a decade (100kHz) than the highest frequency humans can hear (20kHz). Skin effect is a real problem RF Engineers deal with all the time.  Although it’s measurable at audio frequencies, it’s mostly negligible, hence why there is so little written about it from peer-reviewed sources when dealing with audio.

So, companies come up with elaborate ways of allegedly reducing the “skin effect” problem.  We’ve measured many of these so called “skin effect” free cables and, the reality is, many of them have higher DC resistance right off the bat because they use high gauge conductors. So even though they can maintain a more linear frequency dependent resistance and inductance profile as frequency goes up, they still have HIGHER resistance than ordinary 12 AWG speaker cable even up to 100kHz.  You can see this in some of our measured data in Speaker Cable Face Off I  and Speaker Cable Face Off II.

In our Speaker Cable Gauge Article, we show the most important metric when dealing with speaker cables is DC resistance.  The lower the gauge of cable, the less resistance it will have.  We even tabulate a recommended AWG of cable you should use based on the length of the run and the impedance of your speakers.  This will help minimize insertion loss which is DIRECTLY related to the cable’s resistance.   One should NEVER sacrifice low DC resistance to mitigate other alleged problems at audio frequencies for speaker cables.

Table 1. Recommended Cable Distances vs Gauge

Other Crazy Pseudoscience:
Other crazy pseudoscience includes slapping a battery across the dielectric of the cable to allegedly reduce distortion by keep the cable’s dielectric “broken in”.  The battery itself doesn’t conduct but it sure looks pretty having a black led backlit box attached to your cables.   The whole notion of cable break-in is yet another myth that has no basis in science or logic for that matter. Music is an AC waveform, always changing in amplitude and phase.  The idea that the cable somehow aligns itself to some optimal state is not only a fallacy, but it’s an embarrassment that there are companies knowingly reporting this nonsense as some engineering truth.

Similarly the idea of a piece of wire, much less the dielectric, introducing non-linear distortion is complete hogwash.  This is something that is immeasurable even with test equipment 1000’s of times more sensitive and consistent than the human ear.

Some companies even go so far as to convince their customers that it’s beneficial to cryogenically freeze their cables prior to using them.  They theorize that this will align the crystalline structure of the copper so that it will produce less distortion.  What they fail to tell the customer is that any beneficial realignment that may have occurred will be nullified once the cable comes back to room temperature.  I suspect they may see more benefit having their cables soaked in Kosher chicken fat and blessed by a Rabi.

You can read about more cable myths in our: Top Ten Signs a Cable Vendor is Selling you Snake Oil

Hugo: Why hasn’t the FTC regulated the claims exotic cable companies make?

Gene: Good question.  I believe the FTC has bigger fish to fry than worrying about some of the extravagant claims made by exotic cable vendors.  The cables themselves can’t cause any physical harm to humans other than perhaps making their wallets a bit thin.

Hugo: Why do these companies feel the need to make such claims?

Gene: AV cables and speaker wires are very basic in nature.  Cables themselves are boring passive devices that do nothing more than connect AV gear together.  Well designed cables are easy to make and are sonically indistinguishable from each other.  Thus, it’s hard to make a sale unless you can tell a good story.  Cosmetics alone won’t do it because people want to buy into the idea of something mysterious and/or beneficial.  They like hearing that their cable choice will bring out the chocolatey midrange in their speakers or release magic pixie dust to bring them a more audiophile experience.  The power of suggestion again reigns supreme. We recommend reading the Audioquest Demo Experience article we’ve previously written on this topic.

Hugo: So what do you recommend when shopping for AV cables?

Gene: Don’t buy into the pseudoscience some exotic cable companies like to market and DON’T trust glowing cable reviews from the AV press.  Buy expensive cables only if you wish to dress up your system. Realize that a cable will NOT perform magic on your system.  Don’t use cables to attempt to improve the fidelity of your system.  You get much more mileage by concentrating on better speaker placement, and improving room acoustics.  Buy cables that are solidly engineered using proven design principles.  I personally like to know how cables measure so if a manufacturer is unwilling to publish the measurements of their cables or they claim measurements don't matter, be leery. 

Speaker Cables:

High end speaker cables should at least have comparable or better Resistance (Rdc), and Inductance (Ls) measurements than standard 12 AWG Zip cord.  The Capacitance (Cp) may often be a bit higher if the designer is attempting to minimize inductance, but that is not a problem provided it isn't so high that a Zobel network must be attached at the speaker end to prevent the amplifier from oscillating.  This usually only occurs with flat speaker cables that sandwich the conductors on top of each other separated only by a very thin insulator. In such cases, the consumer is advised to proceed with caution as some amplifiers may not perform well under such a high capacitive load, especially if the cable run becomes exceedingly long.

Typical 12AWG Zip Cord Measurements :

Rdc: 3mohm/ft

Ls: 0.200uH/ft

Cp: 25pf/ft

Electromagnetic pickup is rarely a concern with speaker cables.  However, if you live in close proximity to HAM radio tower, then there is no harm in using twisted pair or shielded twisted pair speaker cables to eliminate the chance of EMI noise pickup.  Twisted pair cable is beneficial when you're parallel running multiple sets of speaker cables in close proximity to reduce crosstalk or mutual coupling though we've only heard/measured such phenomenon when the amplifier end of one speaker and its associated cable was left unterminated (disconnected) to the amplifier while the adjacent speaker cable was transmitting a large signal to power another speaker. The audio signal transmitting from the powered speaker cross coupled over to the disconnected speaker cable and actually drove the attached speaker of that cable to audible levels sitting 15 feet away from the speaker!

See: Eliminating RFI/EMI Noise from your Audio System

Safety Tip: It's a good idea for safety and radiated/conducted reasons to never leave a speaker cable connected to an actively powered amplifier without an attached speaker or dummy load. 

WBT Compression Banana Connector

I also think it's important to chose cables that have quality terminations.  I prefer WBT compression banana plugs that you twist to expand into the speaker/amplifier binding post to make a very secure connection over bare wire or spade connectors.  Having a solid contact between the cable and the interfaces (speaker and amp/preamp) minimizes contact resistance and thus further minimizes losses.

Audio Interconnects:

For audio interconnects, shielded twisted pair or shielded COAX work extremely well for audio.  Unshielded twisted pair is good for rejecting magnetic pickup but not so good at eliminating capacitive pickup (unless the interfaces between components are balanced).  Shielded twisted pair provides excellent shielding for low frequency signals in which the magnetic pickup is the major concern. The effectiveness of the twisting increases as the number of twists per unit length increases.  Shielded twisted pair is more than enough for frequencies below 100kHz, but above 1 Mhz the losses in the shielded twisted pair increases considerably.  In addition, a twisted pair cable cannot maintain the proper impedance necessary for video applications (75 ohms).  This is why I generally prefer double braided foil shielded COAX cables designed to be used for video applications such as the Belden 1694A or equivalent.  If a cable can pass video signals over long distances with no problems, it will easily handle any line level audio signal without any loss of signal or fidelity or chance of noise pickup, or cross coupling from adjacent cabling. 

For more detailed information on identifying quality Video Cables, check out: Component Video Cable - Definitive Guide

Turbine Connector (left Image)l WBT Compression Connector (right image)

Termination quality is also an important consideration.  I don't care for the turbine RCA connectors as they tend to lock down too tightly on an RCA jack which can actually rip off the connector if you don't carefully twist the cable as you are removing it from your AV gear.  Canare type RCA connectors make a nice snug, but not overbearing connection as do the compression WBT type connectors.

Balanced XLR Connectors

The same principles apply for balanced XLR cables.  I do prefer the locking balanced connectors that snap into place on the component gear as they make a more secure connection without risk of being accidentally pulled off if one should tug on a cable when getting behind their AV rack to make changes.

Power Cables

What about power cords (or chords) you might ask? In spite of some of the hogwash you might read, the only factor affecting performance is whether the gauge of the cord is adequate. Consequently, we simply recommend sticking with the stock OEM cables provided by the manufacturer. If a replacement is needed for some reason, buy a cable of the equivalent gauge. If you need a significantly longer power cord than the original, then it may be advisable to use the next sized lower gauge cable relative to the original cord, say from 16 gauge down to 14 gauge. Beyond that, we’ve seen no demonstrable differences between “high end” cords and their less costly brethren.

If you wish further reading on this topic, check out our very detailed article:  Audio Power Cords: Do they Really Make a Difference?

Conclusion

It's important to keep in mind that AV cables are very profitable accessory items.  Installers and Dealers love to tack them onto an install job to make some extra cash.  Most electronics and loudspeaker manufacturers don't offer much of an opinion on this topic to not alienate their dealer or installer network.  

Transparent Cable Demo Booth at a Recent CEDIA Trade Show EXPO

Big box stores typically get significant incentives to promote high end cables and thus often have the very cable vendors promoting the pseudoscience train their store employees on why consumers should purchase these accessory items.  A convinced salesman is an effective tool to sell your product!

As previously mentioned, it's very challenging for an exotic cable vendor to make their product stand out in a crowd of similar performing products on the shelf of an AV Specialty Store; hence why they must concoct a good story.  Thus the birth of pseudoscience is often a necessary evil to make manufacturers products appear "unique" or "better".

Our motto with cables has always been "only poorly designed cables can be sonically distinguishable".  One has to really go out of their way to design such a cable.  We don't recommend using cables as glorified tone controls.  So choose wisely based on provable design principles and metrics rather than a fancy story or packaging.