Exploring Audio Urban Legends

0

Demystifying Common Audio Misconceptions

Exploring Audio Urban Legends.indd

Whether you are a serious music listener or a neophyte in this wonderful hobby, I am sure many of you can’t help wondering if the numerous urban legends surrounding high-end audio are true, false or if the jury is still out.

There is a real dichotomy surrounding most of these issues because the general sphere of audio engineering has a very strong science foundation and most of the reputed brands design their audio products based on strong and proven scientific principals. However, the industry has its fair share of assumptions that are based on pseudoscience. A few manufacturers use these assumptions to design and sell products in the hope that the customer will trust in the sales pitch and have faith in the veracity of the claims made for the product.

There is a common argument that is used in the world of audiophiles to justify why scientific measurements don’t support claims of superior performance. They opine that science has not advanced to the stage where it can measure the superior sound quality being delivered. When readers ask me about audio products that make claims that do not seem to have any basis in scientific fact, the general rule of thumb that I recommend is that they should adopt the ‘try before you buy’ strategy and that they part with their hard earned money only if they hear a positive difference in the sound quality that is commensurate with the price being asked for the product. One caveat here is that they should audition the product without being subjected to a cleverly crafted sales pitch by a slick sales person with a great gift of the gab. This is because a skillfully delivered spiel is quite capable of playing tricks with your brain and results in you hearing things that you would not otherwise hear.

If you have any doubts about this phenomenon, I would recommend that you watch the video clip titled ‘Audio Myths Workshop’ on YouTube which includes a demonstration by Poppy Crum where she plays Led Zeppelin’s Stairway to Heaven, backwards and to most people it sounds like nothing but incomprehensible gibberish. However, when she plays the same musical passage again accompanied by text of lyrics on the screen, you can hear the words contained in the text in what your brain previously perceived to be gibberish.

This is a powerful exercise that reveals how you can start hearing things when a slick sales pitch suggests to you what you should be hearing. Our brain has a powerful ability to fill in gaps in sound that it perceives should be present, irrespective of whether the sound in question is present or not. Subjecting yourself to a cleverly devised sales pitch before you hear the product will activate this ability in your brain and prompt you to hear what may or may not be in the actual sound reproduction.

Whenever I happen upon obscenely priced audio products that have no science to back up their claims, I can’t help but think of the lyrics of a Greg Brown song called “Where is Maria” where he croons “There will be one corporation selling one little box, it will do what you want and tell you what you want and cost whatever you’ve got”.

Some urban legends surrounding high-end audio have been with us for many decades and continue to generate endless controversy. One of the more common is the digital versus analog source component argument. I will concede that when the compact disc made its debut, despite its claims of ‘perfect sound forever’ it was anything but. Digital sound was harsh, edgy and glassy compared to analog, especially vinyl. However, thanks to advances in digital technology, we now have ways to reproduce music in the digital domain with most of the characteristics that we value in analog sound without the pops, clicks and crackle that are part and parcel of listening to vinyl records.

Granted, the reproduction delivered by the very best turntables, tone arms and cartridges meticulously calibrated for optimum performance and playing mint condition vinyl records, does have a magic that even the best digital systems may not deliver, but the initial and on-going costs of attaining this ideal case scenario can be quite exorbitant and well beyond the reach of the vast majority of audiophiles. This being the case, unless you have deep pockets and the willingness to dip into them initially, for a state-of-the-art record player and tone arm and then periodically for accompanying accessories like cartridges, you are better off investing in a good digital to analog converter and feed it with a digital player like the Bryston BDP-2, a media player like the Pathos or a computer loaded with a well designed player like Pure Audio, Amarra or Audirvana which you can download for a very reasonable price. As for ergonomics, ease of use and maintenance, digital sources beat analog sources hands down. Of course, if a big chunk of your enjoyment as an audiophile comes from endless tweaking, then the turntable is just what you need.

Another widespread urban legend in the field of high-end audio is that very powerful amplifiers can damage speakers that do not have high power handling capacity. It is absolutely possible to damage speakers by driving them to window rattling levels by ultra powerful amplifiers. However, you are more likely to damage speakers, especially tweeters, by driving them with underpowered amplifiers that clip like crazy when driving the speakers. If you listen to your gear at reasonable volume levels and never feel the need to turn the volume all the way up, you are less likely to damage your speakers with an amplifier with power to spare vis-a-vis an underpowered amplifier that is unable to deliver enough current during musical peaks and thereby go into oscillation sending very high pitched signals to the loudspeakers that could fry your tweeters.

Another urban legend is the claim that audio systems that deliver frequencies that go well over the audible spectrum sound better than their counterparts that handle only the audible spectrum. As human beings, the audio frequencies that we hear are around 20 Hz to 20 kHz. Our ability to hear the frequencies at the upper end of this range tends to deteriorate as we age. Despite this many audiophiles are quite willing to pay exponentially more for gear that reproduces sound that is well above and below our audible frequency spectrum. Is this true or just another urban legend?

At the lower end, there is no doubt that we can detect frequencies below 20 Hz, but in most cases we tend to feel these frequencies rather than hear them. When listening to a live performance we often encounter frequencies below 20 Hz, which we feel in our bones rather than hear. This means that if you want to reproduce this same sensation when listening to reproduced music, it would behoove us to reproduce those frequencies via a true full-range speaker or by adding a well-designed subwoofer that integrates well with our main speakers.

As for frequencies above the audible spectrum, one assumption is that although we may not be able to hear them, they help complete the music listening experience by positively influencing the frequencies that we can hear. This prompts many speaker manufacturers to incorporate super-tweeters into their loudspeakers, in many cases these super-tweeters are located on the rear of the speaker, firing backwards. The wisdom of this design strategy is debatable and I would take you back to my rule of thumb, i.e., if you cannot hear the difference, don’t pay extra for it.
One urban legend that has been around for quite a while is that gold plated connectors deliver better performance than their counterparts made of tin, nickel or other metals. The fact of the matter is that gold, in itself, does not have any extra special properties that help transmit a signal better. The advantage of gold plating is that it does not oxidize and tarnish like many other metals and so the connection and therefore the signal transmission does not deteriorate over time.

Since gold is so expensive, the coating of this metal that most manufacturers use is extremely thin, typically just a few microns thick. This, combined with the softness and malleability of this metal means that the gold plating can wear off with repeated plugging and unplugging and so if you want to retain the advantage of the gold plating, you have to literally handle them with gloves and minimize the number of times you plug and unplug the connectors to minimize the chances of the gold wearing off.

One urban legend that has evoked passionate discussions that include raised voices and flared tempers is the superiority of high-end cables over their more pedestrian and modestly priced counterparts. Opinions on this span an incredibly wide spectrum, from “fancy cables are no better than wire coat hangers” to “they can make or break a high-end audio system”. The truth of course, is somewhere in between.

The four most important factors that determine the performance of cables are inductance, resistance, capacitance and skin effect. Obviously, low resistance at audio frequencies is highly desirable. If the resistance is too high it could adversely affect the amplifiers damping factor. The damping factor is the amplifiers ability to absorb voltage fed back to it from the speaker. In a real world situation, when you send a tone to the driver unit of a speaker and then stop the signal, due to inertia, the cone continues to vibrate and this process generates a voltage. To stop this undesirable vibration the amplifiers output circuit presents a low impedance load.

Cables with high inductance and capacitance usually result in loss of high frequency signals and this is more prevalent in cables that are unusually long. If your speaker cables are in the 8 to 10 feet range, this is less of a problem. Some manufacturers use network boxes as part of the cable run to compensate for the length of the cable. This is also controversial and many feel that a network is just a way of compensating for a badly designed cable.
Many of the über expensive cables try to justify their obscenely high prices by claiming that they possess a frequency capability that extends into the megahertz range. Here again, you need to carefully listen to detect if you can tell the difference. If you can’t, don’t waste your hard earned money.

Skin effect is the tendency of current to flow on the outer surface of a wire. Since the inner portion of the wire carries less current, the overall effective resistance of the wire is greater at the higher frequencies. Some manufacturers have tried to counter skin effect by adopting proprietary geometry like hollow oval configurations. Another technique is to have many separate strands in the cable and insulate each one individually. This configuration is called Litz wire and if implemented well, it does help mitigate some of the problems caused by skin effect.
A good rule of thumb here is that you should only audition cables from reputable companies that are priced within your budget and a few models that are one or two price levels down. If the cables that are in your price budget sound distinctively better than their lower priced counterparts, then shortlist those and make your final choice based on the ones that sound the best to your ears. If you cannot hear any difference between the cables in your price range and the lower priced models then go for the most affordable option provided the build quality is top notch.
If you cannot afford the high prices of fancy cables, you need not worry all that much. It is possible to get performance that is quite satisfactory with a 12 to 14-gauge oxygen free copper wire for runs that are less than 10 feet, which you can purchase at the better hardware stores. If you go down this route, you need to ensure that the terminations, be they spades or bananas, are done well, as the quality of the terminations do contribute significantly to the overall performance of the cable.

One urban legend that is related to most audio gear is the assumption that components need to be broken in before they reach optimum performance. When it comes to gear that has moving parts like CD players and speakers, this assumption makes a lot of sense in that the moving parts need to gel with each other for a time before the component delivers its best performance. This assumption is more controversial when related to gear with non-moving parts like cables and interconnects.

My personal experience has been that, with most components, I can easily hear the difference between the performance of a component used right out of the box to one that has had been through a breaking in process, whether it has moving parts or not. However the difference is definitely more pronounced with components that have moving parts. In this case, you have nothing to lose by subjecting your new gear to a breaking in process before doing any serious listening. If it sounds better, you stand to gain, whereas if it does not, you have not lost anything.
Yet another highly controversial urban legend is that tube amplifiers deliver sound that is closer to the live performance than their solid-state counterparts. My take on this is that it depends on the design of the amplifier and the quality of the parts used. Assumptions that all tube amplifiers sound better than all solid-state amplifiers or vice versa are inherently flawed. I have heard outstanding solid-state and tube amplifiers but I have also heard horrid sounding amplifiers in both configurations.

Generally speaking, one advantage that solid state amplifiers have is a better damping factor that translates to better bass control that only the very well designed and usually very expensive tube amplifiers can match. Conversely, tube amplifiers deliver even order harmonics, which are more pleasing to the ear when compared to the odd-order harmonics that solid-state amplifiers produce. Even order harmonics tend to add overtones that are richer than their odd order counterparts. Having said that, you need to keep in mind that all distortion adds intermodulation to audio products, which is not harmonically related to the source signal and so the result is sound that is further away from a live performance. Tube aficionados point out that tube based circuits react more smoothly and with less harshness than solid-state circuits when they are driven to the point where distortion is generated. This is subjective, so you should trust your ears to verify this claim.

Here again, it comes down to personal preferences. Once you have determined how much you would like to spend on an amplifier, you should audition the leading tube and solid state based contenders in that price category and then let your ears decide which is more pleasing to your ears. If, to your ears, the differences are not significant, then going for solid-state is a no brainer, because it eliminates the need and expense to change tubes periodically.

There are exponentially more audio urban legends than what we have covered here and in my opinion they add a lot more interest, mystery and intrigue to this wonderful hobby. While we enjoy exploring these legends it is important to be cognizant of the fact that a few unscrupulous people in this industry are always attempting to use these legends to part you from your hard earned money. This being the case, it is important to understand which of these legends ring true and which are just voodoo, exploited by snake oil peddlers. This understanding plays an important role in our intrepid journey to acquire the best possible sound and getting the best value for our finite budgets.