A Brief Guide to Audio for the Skeptical Consumer

09Oct13

…Or What I Wish I’d Known Before Ever Setting Foot in a Hi-fi Store

The following is my attempt to succinctly describe what audio skeptics believe about basic issues related to sound quality and consumer audio equipment. This may seem inconsequential to some, but then again music itself may seem inconsequential to some. Rather than focus on my own opinions—which matter little—I am trying to objectively describe what knowledgeable audio professionals and engineers of a skeptical—or just plain scientific—mindset believe about these issues.

I’ve come to understand that much of what is purported as truth in the audio industry is as objectively false as the alleged facts used to peddle most vitamins, new age mysticism, and cuckoo conspiracy theories. I find it baffling how much useless information there is online about audio issues, much of it written by professional writers or even recording engineers. (To paraphrase audio expert Ethan Winer, being a recording engineer is nothing like being virtually any other kinds of engineer, who might be responsible for, say, designing an airplane to carry hundreds of people over an ocean. Perfectly competent recording engineers often possess a minimal amount of education and may be wholly ignorant of the deeper science involved with what they do.)

To me, an “audio skeptic” is roughly synonymous with an “audio objectivist.” An “audio objectivist” believes that controlled experiment (e.g. double blind) offers the only effective method for getting around confirmation bias (similar to the placebo effect). This understanding can create doubt about most of what is written about audio products even by professionals. Unfortunately, it can also make one come across as rather arrogant, especially when interacting with individuals who adamantly insist that upgrading to an exotic brand of audio cable did, well, anything at all. Skeptics tend to favor legitimate science—with published studies and peer review—and distrust junk science. Skeptics debunk—sometimes gleefully—and in the audio world, there’s no shortage of easy targets. (Here and here are overviews of the subjectivist vs. objectivist holy war. Here and here are lists of double blind audio tests.)

But dude, how are a bunch of eggheads going to tell ME what sounds good to MY ears? This is a valid point, and of course everyone has preferences about what sounds good, and there are many areas where experts vehemently disagree. However, the assertions made here have nothing to do with preferences. No one legitimately prefers the sound of a one speaker cable to another, because barring some gross defect, those cables do not have their own sonic signature. The harsh truth is that when someone pays thousands of dollars for a speaker cable and then hears an “obvious” sonic improvement, they are deluding themselves, which can be easily demonstrated under bias-controlled conditions and also deduced using the laws of physics.

My audience is someone like myself a few years ago first getting into this stuff and ignorant about all issues or controversies related to audio. I’d long ago worked out how I felt about homeopathy or astrology, but I was clueless at how skepticism might relate to audio issues. Perhaps if I’d read something like this it would have prevented a few expensive detours.

Again, these ideas don’t come from me. I am attempting to distill what the majority of credible professionals think about audio issues. I believe that most individuals of a skeptical mindset who get into this stuff will come to all the following conclusions:

1. Exotic cables, interconnects, or power cords don’t make your system sound better. Not even a little bit. And bi-wiring simply doesn’t make sense.

  • “Seven different songs were played, each time heard with the speaker hooked up to Monster Cables, and the other time, hooked up to coat hanger wire. Nobody could determine which was the Monster Cable and which was the coat hanger.”Do Coat Hangers Sound As Good Monster Cables? @ Cosumerist
  • “We will find that every topic Pear claims is important to cable design has been debunked as nonexistent, inaudible, or insignificant at audio frequencies. Coupled with the fact that exotic cable designs are not used by the professional broadcast and recording studios that produce the recordings in the first place, this non-issue of cables is further diminished in significance.”Pear Cable Redux: How to Combat Scam with Science @ Audioholics
  • “I believe pseudoscience dominates and drives much of what goes in in the hi-fi industry. Here I say that audiophile cable companies are reliant on pseudoscience to sell their products and as such are conning their customers.”Pseudoscience and the audiophile @ The Skeptics Society Forum
  • “Pointing out the absurd review by audiophile Dave Clark, who called the cables ‘danceable,’ Randi called it ‘hilarious and preposterous.’ He added that if the cables could do what their makers claimed, ‘they would be paranormal.’”James Randi Offers $1 Million If Audiophiles Can Prove $7250 Speaker Cables Are Better @ Gizmodo
  • “When confronted with the truth, believers do not want to hear about it. They want to remain in the magical world of fantasy where they think they can hear improvements in their wire, often arrived at by making listening tests without adequate controls or understanding of the problems involved including speaker impedance and amplifier stability.”Speaker Wire: A History by Roger Russell
  • “To justify claims of enhanced audio quality, many marketers of high-end speaker cables cite electrical properties such as skin effect, characteristic impedance or resonance; properties which are generally little understood by consumers. None of these have any measurable effect at audio frequencies.”Speaker Wire @ Wikipedia
  • “Because there are often very little measurable and audible differences between cables, many of the exotic cable vendors use psuedo junk science to differentiate their products from their competitors.”Top Ten Signs an Audio Cable Vendor is Selling You Snake Oil @ Audioholics
  • “In some cases wire can affect high frequencies passing through it, and connector tarnish or bad soldering can cause distortion. But usually when people believe they hear differences with cables it’s due to improper testing. Everything about wire has been known fully for at least 100 years!” – Sounding Off: Wire @ Sound On Sound Sounding Off: Wire @ Sound On Sound 
  • In summary, I can say with assurance that sonic differences between speaker wire exist in the mind of the listener, not in the ‘sound’ of the cable.” – Wired Wisdom by Tom Nousaine

2. It is unlikely that expensive CD players or DACs improve sound quality. Many of the claims these manufacturers make do not stand up to scientific scrutiny.

  • “A great deal of money has been made by shrewd marketeers preying on the fears of the consumer worried about jitter. Such products marketed include disc stabilizer rings to reduce rotational variations, highly damped rubber feet for the players, and other snake oil remedies.”A Fundamental Introduction to the Compact Disc Player by Grant Erickson
  • “Some audiophile manufactures making jitter reduction claims are likely just touting the features built into whatever chip(s) they’re using and going off the datasheet for the part(s). Some, I know for a fact, don’t even have equipment to even properly measure jitter.”Jitter Does it Matter? @ NwAvGuy
  • “Virtually all of the after-market tweaks and expensive mods are aimed at wealthy gullible audiophiles who are easily persuaded to part with their money. Of course, lacking any proper blind A/B comparisons, if they’ve paid lots, they’ll hear a difference.”Does Digital Jitter Matter? @ eCoustics
  • “Every low-distortion electronic signal path sounds like every other. The equipment reviewers who hear differences in soundstaging, front-to-back depth, image height, separation of instruments, etc., etc., between this and that preamplifier, CD player, or power amplifier are totally delusional. Such differences belong strictly to the domain of loudspeakers.”Electronic Signal Paths Do Not Have a Personality! @ The Audio Critic
  • “With modern digital devices jitter is typically 110 to 120 dB below the music, even for inexpensive consumer-grade gear. In my experience that is far too soft to be audible.” –  Artifact Audibility Comparisons @ Ethan Winer 
  • “‘With music,’ the report asserts, ‘the numbers indicate that the scores were not significant, and it is difficult to imagine a real-life situation in which audible differences could be reliably detected or in which one player would be consistently preferred to another for its sound alone.”Expert Ears Take a Test to Resolve the Great CD Debate @ The New York Times
  • “Apple has more smart people and more resources than any other audio company on the planet, so as we see when it comes to audio engineering, the iPhone easily outdoes many so-called “audiophile” products. For enjoying music, you will probably get poorer performance if you waste your time and money with outboard DACs or headphone amplifiers; the iPhone already has the best there is. Why do commercial audio magazines tout external DACs and amplifiers? Because that what their advertisers are trying to sell!” – iPhone 6S Plus Audio Quality @ Ken Rockwell

3. Under normal conditions, virtually all audio amplifiers/receivers sound the same (sans EQ). They do not have their own sonic signature that must be carefully paired with speakers.

  • “They may sound different if they are used at high volume levels as they approach the limits of their output ratings, when the amplifiers’ distortion is rising and nearing the clipping point. However, if two different transistor amplifiers have the same smooth, linear frequency response, low distortion, and are operated within their output ratings, then they will tend to sound identical until they are called upon to produce great quantities of clean, unclipped power.”10 Things about Audio Amplifiers You’ve Always Wanted to Know @ Audioholics
  • “Then I started to hear about some convincing blind tests and finally conducted my own. I was stunned at the results. I couldn’t tell a $300 amp from a $3000 in the store I was working at. Neither could anyone else who worked there. It was a major blow to my audio belief system.”Blind Listening Tests & Amplifiers @ DIY Audio forums
  • “His challenge is an offer of $10,000 of his own money to anyone who could identify which of two amplifiers was which, by listening only, under a set of rules that he conceived to make sure they both measure ‘good enough’ and are set up the same. Reports are that thousands of people have taken the test, and none has passed the test. Nobody has been able to show an audible difference between two amps under the test rules.”Richard Clark $10,000 Amplifier Challenge FAQ by Tom Morrow
  • “Any amplifier, regardless of topology, can be treated as a ‘black box’ for the purpose of listening comparisons. If amplifiers A and B both have flat frequency response, low noise floor, reasonably low distortion, high input impedance, low output impedance, and are not clipped, they will be indistinguishable in sound at matched levels no matter what’s inside them.” – Obsession with Amplifiers @ The Audio Critic
  • “The loudspeaker will determine how your music system sounds. Not the amplifier, not the preamplifier, not the CD or DVD player, nothing but the loudspeaker. Speakers, even the finest, are far less accurate in terms of output compared to input than any of those other components. The speaker will be invariably the weakest link in the chain, the link that limits the quality of sound reproduction.”A Note About Loudspeakers @ The Audio Critic
  • “But for now, the evidence would seem to suggest that distinctive amplifier sounds, if they exist at all, are so minute that they form a poor basis for choosing one amplifier over another. Certainly there are still differences between amps, but we are unlikely to hear them.” – Do All Amplifiers Sound the Same? @ Stereo Review
  • “No one has ever produced a scientifically controlled listening test showing that well-designed amplifiers (flat frequency response, no clipping), preamplifiers, integrated circuits, and speaker wires (16-guage and bigger) have the slightest effect on the sound being produced.” – Can You Trust Your Ears? by Tom Nousaine
  • “An apparently insurmountable objection to the existence of non-measurable amplifier quirks is that recorded sound of almost any pedigree has passed through a complex mixing console at least once; prominent parts like vocals or lead guitar will almost certainly have passed through at least twice, once for recording and once at mix-down. More significantly, it must have passed through the potential quality-bottleneck of an analogue tape machine or more likely the A-D converters of digital equipment. In its long path from here to ear the audio passes through at least a hundred op-amps, dozens of connectors and several hundred meters of ordinary screened cable. If mystical degradations can occur, it defies reason to insist that those introduced by the last 1% of the path are the critical ones.” Science and Subjectivism in Audio by Douglas Self
  • “Now that I have mentioned these various types of distortion, I think it’s safe to say a well designed amplifier will reduce these effects to the point of inaudibility. Because of this, and because of the conclusions from blind listening tests, it’s not clear why some people hear differences in how amplifiers sound.” Amplifier FAQ @ AVSForum

4. “Burn in” factor—the idea that speakers or electronics sound better after X hours of use—is likely a delusion. Though slight measurable differences may occur with speakers, far more likely is that perceived change is the brain acclimating to speaker.

  • “Capacitors polarize within seconds of applying voltage. Beyond that, I dare them to explain what will change in an opamp, cable or PCB as the result of applied voltage and signal. Rubbish.”Audio Myths & Marketing Tricks: Burn In @ ColdCraft
  • “Running your components and cables for some arbitrary length of time when they are first purchased isn’t helpful.”The Mythical Burn-In Period @ eCoustics
  • “In this article we’ll look at a typical electrodynamic driver’s operation as seen largely from the mechanical side, with a view to assessing the validity of various claims frequently made regarding driver break in. We’ll also see why it’s in a manufacturer’s best interest to ensure their products are broken in long before leaving the factory warehouse and how that bears on subsequent attempts at burning a driver in.”Speaker Break In: Fact or Fiction? @ Audioholics
  • “Our audio memory is notoriously short, and it is simply impossible to hear a change that takes weeks to occur. What really happens is that we become ‘acclimatised’ to the sound – there is rarely any significant change at all. This is doubly true of cables – there isn’t any reason whatsoever to break-in an interconnect or speaker cable, because they don’t change enough to create a measurable change, let alone one that’s audible.” Audio Myths by Rod Elliott

5. Expensive vacuum tube electronics may add “character” (i.e. distortion) to your system, but if clarity (less distortion) and reliability is what you’re after, stick with transistors.

  • “As a general rule, tubes for mainstream audio folks are not inherently bad (though perhaps a bit high-maintenance). However, while tubes are very popular in guitar and other instrument amplifiers due to their unique sound (even-harmonic distortion resulting from asymmetric soft clipping), they are unnecessary in playback amplifiers. Skeptics of tube amplifiers argue that audiophiles prefer the inherent distortion provided in the antiquated technology while paradoxically claiming the sound is purer and more perfect.”Audio Woo @ Rational Wiki
  • “Where do vacuum tubes come in? Nowhere, unless you are a tweako cultist. There is nothing in audio electronics that cannot be done better with solid-state devices than vacuum tubes…. Yes, there exists some very nice tube equipment, but the solid-state stuff is better, cheaper, and more reliable.”Paste This in Your Hat! (What Every Audiophile Should Know and Never Forget) @ Audio Critic
  • “Even if you prefer the sound of tubes, please understand they simply cannot restore any quality that was lost earlier in the recording process. All a tube preamp can do is add an effect that you may find pleasing. Studio monitor amplifiers should never have a “sound;” if they do, they are in error. Tube circuits can affect the sound in a way that is similar to analog tape recorders, and you may in fact find that pleasing.”Dispelling Popular Audio Myths by Ethan Winer
  • “Purely audio considerations aside, many audiophiles prefer the aesthetics of a ‘warm,’ artistically designed (perhaps handcrafted) amplifier over the usual ‘high-tech’ appearance of most solid-state amplifiers. And many of us enjoy the ‘legacy’ feel of the equipment setup when operating vacuum tubes are visible. These are valid reasons to buy hollow-state equipment, if it appeals to you.”Differences in Amp Sound: What’s the Truth? @ audioeXpress

6. The look and feel of CDs or computers can’t compete with vinyl, which can sound amazing for what it is. But there is no music lost “between the bits.” High quality digital formats are sonically superior to vinyl in every measurable way.

  • There is no technical proof of the sonic superiority of the vinyl medium compared to CD. One vinyl record may sound better than its equivalent CD for extremely specific reasons. That does not mean the medium as a whole is superior…. There is nothing wrong with preferring vinyl to CDs, as long as the preference is honestly stated on emotional terms, or is precisely quantified and tied to subjective experience, and not obscured with (fallacious) technical appeals.”Myths (Vinyl) @ Hydrogen Audio Wiki
  • “The most ludicrous manifestation of the anti-digital fallacy is the preference for the obsolete LP over the CD. Not the analog master tape over the digital master tape, which remains a semi- respectable controversy, but the clicks, crackles and pops of the vinyl over the digital data bits’ background silence, which is a perverse rejection of reality.”10 Biggest Lies in Audio @ The Audio Critic
  • “I grew up listening to records up until about ’85, when the CD was already out. And I was involved in testing loudspeakers up at the National Research Council in Canada…. It was quite apparent that the amount of distortion coming out of these devices was very high compared to CD. So what we found was that vinyl was a limiting factor in our ability to do accurate and reliable listening tests on loudspeakers.”Why Vinyl Sounds Better Than CD, Or Not @ Talk of the Nation / Science Friday
  • “There’s no question that LPs and tubes sound different from CDs and solid state gear. But are they better? Not in any way you could possibly measure. Common to both is much higher distortion; LPs in particular have more inherent noise and a poorer high frequency response, especially when playing the inner grooves. I’m convinced that some people prefer tubes and vinyl because the subtle distortion they add sounds pleasing to them…. But clearly this is an effect, not higher fidelity.” – Audiophoolery by Ethan Winer
  • “Let’s not fool ourselves, though. Vinyl is great, but the idea that its sound quality is superior to that of uncompressed digital recordings is preposterous.” – Vinyl’s great, but it’s not better than CDs @ Vox
  • Hey, if you prefer the sound of vinyl that’s great. However that subjective judgment shouldn’t be confused with the objective facts, which show that CD/digital does a far more accurate job of reproducing the original musical signal.”Vinyl vs. CD myths refuse to die @ Electrical Engineering Times
  • I’d wager that there is not one single recording engineer at the peak of his powers in the late 50s who would not have sold his very soul to the devil at that time to get his hands on digital technology. He, and the performers, would have struggled against the chronic limitations of the technology, and we today would have a far richer and more faithful legacy had we jumped directly from 78 shellac to digital. And now those great artistes have departed the stage, and all we have is a shadow of their magnificence.” – Vinyl vs. CD – Harbeth’s owner Alan A. Shaw Compares @ YouTube
  • “Of vinyl’s inherent deficiencies, reproducing bass is one of its most glaring. The other is that the last track on each side of a record sounds worse than the first, due to the fact that the player’s stylus covers fewer inches of grooves per second as it gets closer to the center.” – Why CDs May Actually Sound Better Than Vinyl @ LA Weekly
  • “But here’s the reason why the entire debate is stupid: whether the music is stored on vinyl or a CD is just not that important a part of the overall system. It’s like deciding which of two different cars is best by comparing their spark plug wires. There are many, many variables in the process of playing recorded music that noticeably affect the sound, from the microphones, to the mixing, to the mastering, to the quality of the playback hardware, the amplifier, and (far and away most important) the quality of the speakers and characteristics of the listening room; whether the recording was vinyl or CD is simply not one of these important variables, with apologies to the zealots.”Are Vinyl Recordings Better than Digital? @ Skeptoid
  • “Most people, when discussing vinyl, talk about an “analog sound,” saying that vinyl sounds “warmer” or “richer” than digital. It does; because there is less frequency response (poorer reproduction of high frequencies), and more distortion. Just as tube amps may sound “better” because of the distortion they introduce into playback, the same is true for vinyl. That “warmth” you hear is simply the poor quality of the playback; the distortion caused by the analog chain, and its lack of detail.” – Do Vinyl Records Sound Better than CDs? (Spoiler: Nope)
  • The fundamental cause of inner-groove distortion is the progressive reduction of linear resolution as a record progresses. Put another way: there is more vinyl per second available at the large-diameter beginning of the record than exist at the smaller-diameter toward the end of each side. Subsequently, the wavelengths become gradually shorter and more compressed (like an accordion) as you get closer to the records centre. These more condensed grooves are much harder for the stylus to track accurately.” – Vinyl Record Inner-Groove Distortion @ Sound Matters
  • “CDs reflect exactly what the artists recorded in the studio. Vinyl distorts it. Some listeners honestly feel that the defects vinyl introduces somehow make it more attractive or ‘warmer.’ But from any objective standpoint, there’s no justification in calling the sound of vinyl records ‘better.” – Does Music Sound Better on Vinyl or CD? @ Phys.org

7. “Audiophile” hi-res audio formats are not likely to offer audible improvements over compact disc 16 bit/44.1 kHz quality.

  • “Why push back against 24/192? Because it’s a solution to a problem that doesn’t exist, a business model based on willful ignorance and scamming people. The more that pseudoscience goes unchecked in the world at large, the harder it is for truth to overcome truthiness… even if this is a small and relatively insignificant example.”24/192 Music Downloads (…and why they make no sense) @ xiph.org (See also Monty Mongomery’s superb videos explaining digital audio.)
  • “The authors report on a series of double-blind tests comparing the analog output of high-resolution players playing high-resolution recordings with the same signal passed through a 16-bit/44.1-kHz “bottleneck.” The tests were conducted for over a year using different systems and a variety of subjects. The systems included expensive professional monitors and one high-end system with electrostatic loudspeakers and expensive components and cables. The subjects included professional recording engineers, students in a university recording program, and dedicated audiophiles. The test results show that the CD-quality A/D/A loop was undetectable at normal-to-loud listening levels, by any of the subjects, on any of the playback systems.” Audibility of a CD-Standard A/DA/A Loop Inserted into High-Resolution Audio Playback @ Audio Engineering Society (full text here)
  • “The Meyer/Moran test is persuasive, but I am open to the idea that some further research may prove it to be not the last word on the transparency of 16/44. Still, I’d expect the audible differences between 16/44 and higher resolutions to be subtle at best, and I am sceptical of any claims otherwise.”Is high-resolution audio (like SACD) audibly better than CD? by Tim Anderson
  • “The CD-quality standard—which Young and HRA proponents say isn’t sufficient—wasn’t adopted randomly. It’s not a number plucked out of thin air. It’s based on sampling theory and the actual limits of human hearing. To the human ear, audio sampled above 44.1 kHz/16-bit is inaudibly different.”  – Don’t Buy What Neil Young is Selling @ Gizmodo
  • “Please note that this is not just a disagreement with the cloud-cuckoo-land tweako audiophiles but also with the highest engineering authorities, such as the formidable J. Robert Stuart of England’s Meridian Audio and others with similar credentials. That the Meyer-Moran tests leave no room for continued disagreements is an occasion for the most delicious Schadenfreude on the part of electronic soundalike advocates like yours truly. I stated my suspicions that SACD was no improvement over CD seven years ago, in my review of the first Sony SACD player.”Proven: Good Old Redbook CD Sounds the Same as the Hi-Rez Formats @ The Audio Critic
  • “In theory, rates around 44.1kHz or 48kHz should be a near-perfect for recording and playing back music. Unless the Nyquist Theorem is ever disproved, it stands that any increase in sample rates cannot increase fidelity within the audible spectrum. At all. Extra data points yield no improvement.”The Science of Sample Rates (When Higher Is Better — And When It Isn’t) @ Trust Me I’m a Scientist
  • Much of digital audio comes down to math. You take the sampling rate and divide it by two and that is the highest possible frequency that can be recorded (so 44.1 khz, the standard for CD audio, can go up to 22,000 hz—most adults can hear little above 15,000 hz or so). From the bit depth, you can calculate the theoretical limits of the dynamic range.” – The Myth and Reality of the $43 Download @ Pitchfork
  • “Last month, we issued “The Golden Ear Challenge”: Our promise to write a glowing, feature-length article about whoever becomes the first person on record to show he or she can reliably hear an improvement offered by any super-high-resolution file format under properly controlled conditions. So far, this prize remains unclaimed.”Update on “The Golden Ear Challenge”: Who Will Conquer Audio Mount Everest? @ Trust Me I’m a Scientist
  • “Without going too deeply into the sampling theory behind how they came up with those numbers, suffice it to say that to human ears 44.1/16 audio is mathematically perfect sound reproduction. The frequencies and dynamics that lie beyond might be there—but we cannot hear them.” – What is High-Resolution Audio? @ Gizmodo
  • “Many tests over the years have concluded that nobody can reliably identify CD-quality versus higher resolutions, yet some people still believe that HD audio sounds better, with more realism and clarity. This belief is driven by two myths: 1) ultrasonic freqencies can affect frequencies we do hear, and 2) having 24 bits affords more resolution than 16 bits because there are more vertical “steps” between each sample’s volume level.” – High Definition Audio Comparison @ Ethan Winer
  • “Yet high-resolution audio files at 96 kHz can reproduce sounds up to around 48,000 Hz. Dogs can hear sounds that high; but not humans. In fact, it’s very likely that your stereo system cannot reproduce sounds at such levels.”Why High Resolution Music is a Marketing Ploy @ Kirkville

 

See also my article on what DOES make a difference in audio: A Brief Guide to Audio for the Skeptical Consumer: Part II

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116 Responses to “A Brief Guide to Audio for the Skeptical Consumer”

  1. 1 Dave Rust

    BTW, as a recording engineer, I can lend insight to why we use higher sample rates and bit rates. Our studio uses 96-24. 96kHz is used so that our mixes can be dithered down to both 48 and 44.1kHz with identical results (this is superior to recording in, say, 48kHz and then dithering over to 44.1kHz). Period. There is no reason related to audio quality to record at 96kHz. Dithering to both 48 and 44 is becoming more common as audio is often destined for both audio-only releases (44.1) and video/film use (48). 24 bit recordings provide 30dB more dynamic range than 16bit and, as an earlier poster points out, this allows us to record sounds more accurately in the beginning, while applying compression techniques, as required later, during the mixing process. Digital plug-ins increasingly are able to work in 24, 32, and even 64 bit work spaces, insuring a very accurate summing result and no clipping. In the end, our 24bit mixes can exceed the dynamic range of distribution formats, but they are shoehorned into 16bit ranges by really excellent mastering engineers. The compromise is tiny and, in fact, probably appropriate for most listening environments. Other than creative decisions applied to final masters, I’ve never heard a “quality” difference between a 24bit master and its 16bit offspring.

    • 2 Dave Rust

      Addendum-I erred in saying “never heard a difference” between 16 ad 24 bit. In constructing soundtracks for movies, we use a much wider dynamic than most music. Dialog is often kept at -30dB, to allow lots of room for percussive effects and dramatic music. Foley effects are often very subtle…think rustling clothes and footsteps. In cases like these, a 16bit downsampled version of the soundtrack does indeed reveal limitations. It’s because we generally have the volume up higher than when listening to music. Some ambience and Foley sounds can indeed suffer from detail a tad compared to the 24bit version. In fact, to avoid dithering noise altogether, DVD disks often contain quiet scenes that are more fully normalized but, following encoded instructions, knock those scenes down to their intending quiet level, in real time, after the DA converter.

  2. 3 Steven

    Wow, never has so much been written about the topic of audio with such ignorance. The entire thing can be summarized by stating that the author falsely claims that double blind tests mean anything in audio (they don’t), and that the goal of scientific testing with regards to audio should revolve around filtering out any possible placebo effect. The author is completely stuck on this very small aspect of the scientific approach to audio. It is such a tiny aspect of the big picture, yet the author cannot move past it.

    In reality, DBT’s are not reliable in audio, as many real differences that we know for a fact to be true, show a null result when subjected to a DBT test. The fact is, DBTs are biased towards showing a null result, by creating multiple conditions that bias the test in a particular direction. First, DBT’s do not test the subjects’ listening skills – they test their audio memory. Second, DBT’s are prone to showing a null result because subjects who are selected at random are not trained listeners, and many differences in audio require experience to notice. If you select a bunch of inexperienced listeners, it’s no surprise that the number of people who hear a difference fade into statistical insignificance when weighed against the majority of data which comes from untrained subjects. Third, DBT’s put the subject on guard, and human subjects behave differently when they know they are being watched. DBT’s are essentially a psychological test, where the subject feels like a rat in a maze, and not an audiology test. Many DBT’s are set up to trick folks, where the subject is told that they are listening to two different components, but the experimenter is actually tricking them and playing the same component. When a subject feels like he is being tested, it puts them on guard and they begin to worry about social factors such as avoiding being judged, or wanting to avoid appearing stupid, or conforming with the group, rather than their auditory skills.

    Even in clinical trials, where DBT’s are used most frequently, experienced scientists know that DBT’s have tremendous limitations. Simply google “limitations of double blind tests” and you can read all about it. The bottom line is, audio skeptics act as if DBTs are some kind of holy grail that determines whether something is real or not, but this assumption is completely false. There are many things that we know for a fact to be true that do not show up in DBT conditions.

    Do you need to be blindfolded to know that prime rib tastes better than cheap eye of round? Do you need to be blindfolded and sleep with different women, to try to “test” whether you really love your wife, or whether you are subjectively biased towards her? This desire to subject every aspect of human life to DBT conditions, as if our brains are constantly trying to trick us, is a weird Cartesian obsession where, like a schizophrenic, you constantly walk around believing that some demon is trying to trick you, and you can’t trust anything?

    • 4 spiro spyratos

      So with your comment, you have asserted nothing. That perhaps, it’s all a subjective experience and about personal taste, based on psychoacoustics and maybe esthetics. Let’s give you that insight. The problem is, the audio industry is making false claims based on anecdotal evidence and pseudoscience; yes, principles of engineering are grounded in science and therefore should not be exempt of evidence to support extraordinary claims. The issue is marketing snake oil to the gullible public. When you make claims not supported by science and engineering design, you are willfully lying to the consumer. You may be okay being convinced that looking at a Mark Levinson amp (that happens to be black) has a “darker” sound, whatever that means. But don’t confuse your delusion with reality. When making a purchase, rational decisions can only be made by facts supported by evidence (irrational decisions don’t matter at all, but let’s not confuse the two). This is not the same as art, other than the medium of music which imparts different subjective emotions in everyone, it’s about making false claims about audio tech. When cable companies throw in nonsense about electron directivity or “skin effect”, etc and charge obscene amounts for simple designs, buyer beware. We’re talking about objective, quantifiable, measurable differences that are glossed over or misunderstood by journalists in the bloated BS rags—think Stereophile and TAS. If you can hear the differences between DACs, by all means, spend the money. But don’t be dishonest with your argument. Everyone has the freedom to choose to believe or to buy what they want. I’m not agains that. However, you missed the point of the article, to educate consumers that may not know any better and to caution, buyer beware

      • 5 Sean

        Couldn’t agree more with Spiro Spyratos. There are some interesting parallels to the world of wine here – both have the separable elements of sensory capacity and subjective preference. While we all may have different preferences, that is separable from whether or not we have the sensory capacity to reproducibly find the things we believe we like. Unlike high end audio, blind tasting of wine is generally respected as one of the ultimate ways to answer questions of preference and measure sensory capacity. The highest level you can achieve in the wine world is to be come a Master Sommelier, which requires both extensive book knowledge that anyone could learn as well as an incredibly challenging blind tasting that only people with great noses can pass. These are the sort of people who can recognize they tasted the same wine 20 wines ago in a blind series of 40 wines. Most of us don’t have the level of sensory capacity, and that’s fine – it’s probably a blessing, not a curse. If you blind taste a series mixing $40 wines and $200 wines and you can’t tell the difference, that suggests you could save a lot of money and just buy the $40 ones. If you choose to buy the $200 ones because you can, because you want others to know that you can, or because you like their story better, fine, but you still can’t tell the difference. There’s also the possibility that the particular $200 wines in this test are no better than the $40 ones, and that’s why you can’t tell the difference – they’re not better. The test tells use something about capacity or quality of wines depending how we construct the test.

        Either way, evaluating based only on what we can perceive without any prior bias is one of the surest ways to answer these questions. Steven’s assertion that blind evaluation by people with lesser listening skills somehow invalidates double blind tests misses the point. If the average person can’t tell the difference, then they shouldn’t pay for the more expensive feature. That null result is a very important result, and at the core of the point Spiros is making. The ‘pressure bias’ argument is BS. If I’m the buyer, I WANT to know if I can tell the difference. If it’s a pro listener, they better not feel pressured! The sound memory argument is also BS. You can design the test to go back and forth with randomization to separate (1) can you tell the difference between A and B and (2) if you can, which do you prefer. If you fail (1), then (2) doesn’t matter. By the way, playing the same thing twice is NOT tricking you. That’s called a replicate in science, and it’s literally the way we measure analytical variability and answer question (1). It should always be done via randomization so the order is never predictable to tester or listener.

        The other side of Steven’s comments about the skill of listeners is the issue of whether people with very high audio sensory capacity can tell the difference in blind testing. I would hope Steven would at least agree that if highly skilled listeners can’t tell the difference between any two audio elements in a double blind test, then that element is not producing any perceptible value. If the audio world wanted to prove the value of any given feature/advance, they should at least start by convincing us with proper double blind tests that very skilled listeners can tell the difference. Preference is a separate question. You don’t even get to talk about that until you show me that minimally extremely skilled listeners can tell the difference. If they can’t, neither can the rest, which means you’re selling snake oil (well, I guess it’s only snake oil if you know you’re doing it – you’re just wasting our money if it’s well-intended). My biggest problem with the audio world is that it seems there is no interest in doing this at all, and I can’t help but assume that this is because it would greatly impede their ability to peddle snake oil. (If I’m wrong and there’s an amazing source for results from properly designed double blind tests measuring highly skilled listeners, please educate me). Even if highly skilled listeners can tell the difference and have clear preferences, that still doesn’t mean that most of us can. I suspect the great majority of innovations would fail a proper A/B test with a panel of highly skilled listeners.

        To all of you that don’t want to hear this evil ‘scientific’ view, just admit you like buying the most exotic looking turntable and tube amps because of what they look like and what it says about you. If you want to believe you have great ears and need all this stuff, cool, but don’t say you can tell the difference and then argue against the only method we have that would assess if you can tell. And keep buying that $200 wine.

  3. I absolutely agree with Sean. The human ability to subconsciously bias the way we perceive things based on what we think we should hear/taste/smell etc is a huge factor in audio, and the ONLY way to eliminate that bias is double blind, randomised testing.

    I like the comparison with the world of wine too – very well said Sean.


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