Ex­plor­ing Au­dio Ur­ban Legends

De­mys­ti­fy­ing Com­mon Au­dio Mis­con­cep­tions

NOVO - - CES 2014 HIGHLIGHTS - Mal­colm J. Gomes

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 high­end 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 lo­cat- ed 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 solid­state 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.

Do tube am­pli ers de­liver sound that is closer to a live per­for­mance than their solid-state coun­ter­parts? Pic­tured on the left is the Uni­son Re­search Sin­fo­nia in­te­grated am­pli er, while the right shows Naim Au­dio’s solid state NAP 300 am­pli er with a 300 PS power sup­ply.

What’s bet­ter - an ana­logue or a dig­i­tal source com­po­nent? Above we see the Thorens TD 209 turntable, while the right shows the Brys­ton BDP-2 dig­i­tal player, along with other Brys­ton sup­port­ing gear.

Newspapers in English

Newspapers from Canada

© PressReader. All rights reserved.