Beyond Neutral: Measurements, Blind Testing, Subjective Experience, and Personal Pleasure in Headphone Listening

It appears this is a subject I'll be embroiled in for quite some time. I'm not the first, nor will I be the last, audio writer thus burdened. Steve Guttenberg dragged me into the controversy recently, but he's not to blame. In fact, I thank him, because it was bound to happen sooner or later. My work laptop has been sent to the mothership for IT Tomfoolery, so I'm stuck outside the corporate firewall for a few days, unable to upload pix and graphs to the servers, so I figured I'd spend a little time waxing poetic on the subjectivist/objectivist debate, and Steve's recent comments elsewhere. To offer my views, I'll be a guest on The 404 Friday, June 1 with Steve Guttenberg, and on Scott Wilkinson's "The Home Theater Geeks" Monday, June 18.

It seems to me there's no better way to figure out exactly what one's point of view is than to write it down for all to see. I'm nowhere near as qualified to speak on the subject as John Atkinson or Peter Aczel, but my position at InnerFidelity fairly requires that I establish a position. And since I both measure gear and provide subjective impressions in an effort to help you find just the right headphone, I reckon I do need to formulate and publish a position on the meaningfulness of headphone measurements, blind testing, subjective evaluation, and their relationship to your listening pleasure. Here goes...

The word "neutral" means the sound reproduced by an audio system is identical to the sound signal the system is being fed for reproduction. Measurements indicate the degree to which a system's reproduction meets or deviates from this standard of neutral.

I believe strongly that there is a solid relationship between headphone measurements and what we hear. There's simply no doubt in my mind that when one headphone measures having more bass energy than mid-range energy, you'll hear it as a bass-emphatic headphone. If you zero two headphones' frequency response graphs together at, let's say, 500Hz, and headphone A shows more bass than headphone B, I strongly believe you'll hear headphone A as having more bass. Occasionally you might find someone who disagrees, but in my opinion, they'd just be wrong. Objective measurements are measuring something real, and when you put the headphones on your head, your ears will be presented with that reality.

Our ears are all different from each other, of course, and different from the ears on my measurement dummy head, as well. So there will be differences in exactly what is heard from person to person, or between a particular individual and the measured values, but in terms of measuring a variety of headphones on InnerFidelity's measurement system, I have a high degree of confidence that a fairly accurate picture of the relative differences between headphones is being revealed. "Fairly accurate" needs to be discussed, however.

Objectively, headphone measurements are only moderately accurate. In fact, it's very difficult to identify what "accuracy" even means when discussing headphone measurements. With speakers, we can capture the emitted sound at some distance (usually a few meters) from the speaker using a calibrated microphone and special signals that remove the room from the equation, and we are thereby able to record and characterize with fairly good confidence the performance of the speaker relative to flat ("flat" means essentially the same thing as "neutral"). With electronics, there are no room effects in the way, and simply by careful interconnection and grounding we are able to measure performance with a high degree of accuracy. Headphones, unfortunately, are a dramatically different beast.

Headphones are an acoustic coupler. The headphone, head, ear, ear canal, and ear drum are a single acoustic system and must be characterized as a whole. Because the wavelength of audible sound ranges from substantially longer to similar in length to that of the dimensions of the acoustic space found in a headphone coupler, we cannot view the headphone driver as simply propagating sound towards the ear. Rather, we must think of the driver being coupled to the ear drum through the elastic and potentially acoustically resonant air trapped within the space. You cannot separate or remove any one part from another without changing the nature and performance of the coupler. In other words, there is no place in the coupler where one could say, "Here is where you can measure how flat this system is." We can only deliver electrical signals to the driver and look at the response at the eardrum, and understand that these measurements are a convoluted result of sound going through a complex coupler. I'm afraid that with headphones, finding a very accurate measure of neutral, flat, or transparent will forever elude us. But the data is reliable enough that rational inferences can be made, and by observing the measured performance of very good sounding headphones, a reasonable approximation of "neutral" and "accurate" can become moderately apparent to the educated eye.

Repeatability is another story, however. Macedonian Hero and I went to some lengths to characterize the objective repeatability of my headphone measurement system in this article. In it, we demonstrate that the system's repeatability is within 1dB from 10Hz to about 3kHz; good to a couple of dB between 3kHz and 7.5kHz, and fairly poor varying on average about 8dB above 7.5kHz. I'll hasten to add this is true for only the Sennheiser HD 800 used in the experiment, and on-ear headphones may have poorer repeatability in the lower ranges. Regardless, I'm convinced that the system's repeatability is quite good enough to make meaningful relative comparison between headphones of similar type.

Measurement Meaningfulness
What do I mean by "meaningful"? I have found that measured data from headphones have a fundamental but limited relationship with the subjective listening experience. Here are some areas where I think measurements may inform us about the way a particular headphone sounds:

  • Overall Tonal Balance - Because the frequency response measurements are fairly reliable from 10Hz to 3kHz, I find it fairly easy to look at the measured frequency response and determine the basic tonal quality of the cans. You can see if they are: emphatic or lean in the bass; emphasize or have a sucked-out hollow mid-range; or, up to about 3kHz, if they have a smooth or uneven response.
  • Bass Tightness - A preliminary read on how tight and punchy the bass and low-mids are can be seen in the linearity of the 30Hz square wave top, and in the degree and starting point of a rise in the low frequencies of the THD+noise plot.
  • General Upper Treble Balance - While the frequency response data above 10kHz is all over the place, by visually averaging the amount of energy in the top octave and comparing it to the response below 3kHz, we can see the general balance between upper treble to the mids and bass.
  • Imaging - A preliminary and fairly coarse read on the ability of a headphone to produce an interpretable audio image can be gleaned by looking at the clarity of the leading edge of the 300Hz square wave. A single leading edge with some mild overshoot and quick settling to the wave form top indicates clear acoustic edges with which the brain can accurately determine the arrival time of signals and thereby form a convincing sense of depth and space.
  • Harshness - Again looking at the 300Hz square wave, if the overshoot is extreme, or if the signal rings strongly after the leading edge, you can usually expect that the headphone will sound "biting" or "harsh."
  • Blackness - Though much better observed using Cumulative Spectral Decay plots (CSD, waterfall), residual ringing and noise created by the cans after a sound has been played can be seen in the impulse response plot by observing how long it takes for the headphones to go silent after the impulse. This is a fairly good measure of how "black between the notes" a headphone will sound, or sometimes how "confused" they sound.
  • Isolation - Though not directly related to sound quality, the measurement system does an excellent job of measuring the amount of isolation a headphone can provide.

The meaningfulness of measurements described above allows us to do three things:

  • Coarsely Gradate Headphone Performance - Many, if not most, headphones available for purchase are absolute junk. They sound bad, and measurements will show them deviating strongly from neutral. Careful observation and interpretation will allow you to coarsely sort headphones into three piles: miserable fail; reasonably competent; and potentially very good.
  • General Character - Using the observations listed above (overall tonal balance, bass tightness, imaging, harshness, etc.) one can get a preliminary read on the general sound qualities one might expect while listening. Basic information about whether a headphone is warm, bright, or balanced can be seen in the data.
  • Selecting Personally Suitable Product for Audition - It is my belief the most important thing the InnerFidelity database of headphone measurements offers is the ability to look through a wide variety of headphones for those that might suit your personal listening tastes. I like slightly warm but very linear headphones that enunciate well, but am strongly averse to harshness or treble emphasized headphones. Your listening tastes may differ. By becoming familiar with the basic nature and interpretation of the headphone measurements, you and I could sort through the list of cans and pick those that might please our personal tastes. If we are good at interpreting the data and know our preferences, then our lists of headphones would differ depending on our tastes.
The meaning of headphone measurements is therefore a HUGE step forward in purchasers' ability to narrow down their search for suitable headphones to buy.

I'll readily admit forum dialog and the general consensus developed therein is a very good evaluation tool, as well--better in some ways than measurements in that it includes subjective experience. Unfortunately, that consensus is developed in conversation that can be long, convoluted, spread out over numerous threads, and difficult to find. Even a forum regular like myself will often find it difficult to integrate the forum dialog into a clear picture of a particular headphone's performance. For the general buying public, forum dialog can be a mire of random opinion and noise. A headphone measurement database, by contrast, is dense with meaning for those who can interpret them; is located in one place; and provides an excellent ability to compare headphones directly against each other. Of course, for the general public, headphone measurements can be just as impenetrable as forum yabber. Job security for me, I guess.

My strong conviction that headphone measurements are meaningful and valuable makes me an objectivist of sorts. You might rationally expect that I'm about to espouse the virtues of audio blind testing for evaluative purposes...not really gonna happen.


MacedonianHero's picture

Great article Tyll. I think you pulled the objective measurements vs. subjective experiences together very well. I can't count the many times per month I visit your measurements when I want to confirm what I'm hearing or how 2 particular headphones compare. But ultimately my final judgements are always reserved for listening first with my own two ears.

The Shure SRH940s for example measure quite light in the bass with treble that is too forward for what I'd call accurate. I must have tried these headphones like half a dozen times (most recently just 3 days ago) and every time I hear exactly what is measured. Bass was really hard to hear, it was like Paul McCartney was edited out of the recording unless I absolutely struggled and focused to hear his section on some of my favourite Beatles tunes. The treble was too forward and gave the impression that Ringo was actually in front of the band. Overall not my favourite headphones by a long run, but I couldn't help think how close they sounded to what the measurements say they would sound like.

Limp's picture

Glad to see you made those comments on blind tests.
The woes of a false negative, or type II error, are certainly worth noting, but that really doesn't count as an argument for subjective testing, as that will have an even higher possibility for type I error.
Rigour, that is the the simple and rather boring answer, though luckily you seem to succeed rather well in that, Tyll.

remlab's picture

Read the "Ears can not be trusted" section of this article. Not only is it funny, it is one of the best audio essays I have ever read. It can also be applied to headphone listening which is why I'm including it..
John Krutke is a pretty extreme DIY objectivist, so be prepared if you stray from that part of the article. Stereophile is my favorite magazine, so understand that I don't share his views in regards to his comments about Stereophile reviewers use of subjectivist "power words". I personally think that Stereophile reviewers are the best in the business...

Mark Fleischmann's picture

"Observe how you feel" is excellent advice for listeners.

mikeaj's picture

Right. Humans aren't that great at consistent, unbiased quantification of audio stimulus, so all listening tests have a hurdle to overcome and factors to account for.

Trying to control for biases is just one step out of many for any human experimentation. A lot of blind listening tests aren't particularly conducted that well. Some, particularly those that are single blind, don't really control for the biases. Others produce null results that could potentially be Type II errors. If there's a null result (or one may be expected), then there should be more investigation into establishing a baseline for what people can and can't hear, giving them training sequences using exaggerated examples of what to listen for, maybe ratcheting up the difference until a positive result is gotten, and so on.

There are limitations to blind audio testing, but the problems with sighted audio testing are even more severe.

Anyway, I agree that the headphone measurement database provides a dense source of meaning. Keep it up!

CarlSeibert's picture

Keep up the good work. I especially like the observation that blinded techniques can be a tool for trained or capable observers, not a substitute for them. At least that's what I - subjectively - felt you meant :-)

Tyll Hertsens's picture
Your feelings have plumbed the depths of the unsaid.

remlab's picture

Good looking measurements are like good looking people. After
you've been with them for a while, you realize that good looks are only skin deep. It's their character and inner beauty that ultimately matters. In fact, good looking people can start looking damn ugly after a while, once you get to know them..

Willakan's picture

I would agree that the headphone measurements presented here are inadequate to absolutely characterise the performance of a headphone. Then again, I suspect that if Sennheiser's R&D department were so inclined they could do an excellent job of characterising a headphone's performance with a high degree of objectivity, armed with impressions of the user's ears and head measurements.

I'm not sure whether they still do it, but Sennheiser used to ship a FR certificate with the HD800. It notes that the level of care required to do these measurements accurately is extreme: it apparently takes 10 hours to calibrate the measurement system, with the reference measurement involving "16 acoustic experts". There's obviously an element of marketing here, but the overall impression is of a level of effort which is simply not feasible for anyone who isn't a very affluent headphone manufacturer. I'm sure you could do a better job with 10X the budget and 15 minions at your disposal :D

So, I would agree with you that headphones will remain a bit of a grey area...where you lose me is with your frankly mystifying attack on blind testing which expands out to amplifier and DAC evaluation.

The only difference between sighted listening and blind listening is that one is blind. A well-conducted blind test will begin with the test being performed where the user is aware of what they are listening to and will only proceed to actual blind testing if the user is sure that they can hear a difference. The only parameter that changes is that the equipment is obscured: if the user suddenly can't hear a difference this is because you're trying to turn them into a piece of test equipment? I don't see the logic...

All of the criticisms of blind testing fall flat when you realise that the only qualifying criteria is that it must be blind. You can listen in exactly the same way that you would under sighted conditions: swap between equipment every 3 hours/3 days if you feel like it, make extensive notes, listen to whatever you want in whatever way that you want. Some of the most comprehensive blind tests have been conducted over a matter of months: surely enough time for the user to get to grips with their perceptions?

Ironically, all the evidence suggests that those who conduct blind tests in a way which is anathema to the audiophile who prefers to listen over long periods to get an impression are far more likely to be able to discern differences. Firstly, you've got the incredible fragility of auditory memory, which begins to decay after around 0.2 seconds, if memory serves. Secondly, consider the results of "10 Years of A/B/X Testing", available from the AES Library. They conducted an experiment whereby a group of audiophiles were given boxes, which either transparently passed the signal or added around 2.5% THD. They could then take these home and listen, as they would normally, in their home system, to determine which kind of box it was. They failed, in contrast to those who used blind testing, who were able to distinguish far lower levels of distortion.

So, why on earth should we not use blind testing when amplifiers and DACs are involved? The reason why differences disappear under blind conditions seems painfully obvious, with alternative explanations falling horribly foul of Occam's Razor and other simple logic.

Tyll Hertsens's picture
Thank you for your well formed counterpoint.

Jazz Casual's picture

Well argued Willakan. As for the ideal of neutrality in headphone audio, well it remains just that - an unobtainable fancy at best, a metaphysical concept that sparks interminable debate amongst audiophiles over its existence. It is also a term that is so misused by some Head-Fi'ers who manipulate it to fit their subjective preferences, that it has become almost meaningless. Rather than being a fixed point of reference, it moves along a perpetually sliding scale depending on who is citing it. And just as we all hear differently, headphone measurements can be interpreted differently. It seems that we hear what we want to hear and see what we want to see.

RPGWiZaRD's picture

I totally agree with your final paragraph, it's all about learning your personal optimal sound signature, far too many audiophile people think perfect "neutrality" is the ultimate goal while I'm 99% sure that's not the case, like everything, people got slight derivations in that optimally preferred sound signature, there's probably as many optimal sound signatures as there's people. May be very very small differences in some cases but the point is, neutrality is hardly the ultimate goal to strive for unless you're producer needing to master your stuff, then you want neutral sound unless you purposedly wanted to make it sound in a particular way which would be a "design decision" in that case.

Willakan's picture

It's a thorny one: I think that not many would contest the virtues of genuinely perfect neutrality in recording and reproduction in that it would allow you to perfectly reproduce a real performance: surely the ultimate goal of any hi-fi enthusiast?

In light of the inevitable failure of neutrality on the part of the recording and often the transducer, some degree of colouration can be attractive. The crucial part, IMHO, is to perform any small sound-signature tweaking (ie beyond choosing the transducer) in the digital domain. Why pay for an amp that rolls off the treble and has large amounts of harmonic distortion, for example, when you could do that in the digital domain and turn it on and off as you please?

Tyll Hertsens's picture
" I think that not many would contest the virtues of genuinely perfect neutrality in recording and reproduction in that it would allow you to perfectly reproduce a real performance: surely the ultimate goal of any hi-fi enthusiast?"

Maybe in symphonic, choral, and chamber music there's some semblance of "a real performance" there to be reproduced, but even in those cases recording engineers are trying to capture the performance in a pleasing way. Otherwise, almost all recordings are far from a reproduction of live artists.

Chesky would be one of the few exceptions. (I'll actually be inderviewing Dave Chesky while in NY and asking about his perception of sound.)

The vast majority of recordings are created on the console/computer by the engineer and producer, and worse, they often have the lif(v)e pressed out of them with compressors. I could only hope that as much attention is paid to the recordists art as is lavished on reproduction gear.

That said, I do think a lot of what we would consider mid-fi gear these days is so good that stepping up to the gilded lilies of audiophilia is a bit of a crap shoot. Stereophile has always been my guide there; I think there's none better at sorting poop from prime. (Of course, one has to take my opinion there with a large grain of salt now.)

So I fundamentally agree with you, most well designed electronics are very similar in sound quality---noting your comment that transducers are the tricky bit, and adding that while introducing distortion, tube gear can subjectively vary in ways quite pleasing to some.

When the recordings are largely crappified, giving the sound some pleasing (non-neutral) character might be advantageous to some.

Willakan's picture

I don't have anything against colouration as such: as you say it can seem advisable in some situations. The bit I find puzzling is why someone would want that colouration hardwired into their audio chain, let alone pay a premium to have it hardwired.

As you also say, many recordings are a bit dodgy, but surely it's best to compensate for those with digital processing? That way you can tailor the processing to the content, rather than paying a fortune for some one-size-fits all colouration, which if it indeed exists in any given case (which is often dubious enough!) by definition cannot suit all playback material.

There should be far more emphasis on altering the sound before it hits the DAC IMHO: then again, most are still convinced that tone controls are evil (sigh...) so it looks like a long way to go.

ultrabike's picture

Tyll, I really liked this article. Specially page 2 and the last picture! Priceless!

"As you also say, many recordings are a bit dodgy, but surely it's best to compensate for those with digital processing?" - Willakan

There might be good market for high quality digital processing. I see a large amount of stand alone AMPs and DACs of many sizes and utilizing different topologies. However, I feel equalization and signal processing for some reason are not getting the same level of attention.

I personally would be interested in a set of competing products (portable or not) that can change the sound signature of a rig to better suit your mod today vs yesterday. I don't mean simplistic approaches that "increase the bass", but rather serious efforts to change the whole rig sonic signature... maybe some signature learning rig might be interesting.

Not everything is possible (or practical), and some rigs are just not linear enough to begin with, but I bet there is a lot of room for improvement. Just like the crossfeed circuits, now add binaural effects of different kinds, HRTF equalization mods, acoustical damping compensation, all-pass phase compensation... And from there we could get both low end and high end solutions. Maybe there is just not enough interest in the consumer market for this kind of stuff. Maybe there is, I just don't see it commensurate to to other aspects of audio reproduction: Thousands of dollars in DACs, AMPs, and transducer... with some decent/free equalizer doing digital signal processing. There might be a couple of products out there (Beringher comes to mind) but mostly Pro market.

Timmy's picture

@ultrabike there are some superb digital parametric equalizers out there - a fairly easy to use one is the AIXcoustic Electri-Q one, since it essentially plots a frequency-response based on the settings. It works for Winamp and compatible players, e.g. Foobar, MediaMonkey, etc., comes in a free and a €100 pro-version that adds fancy stuff like linear phase, etc. But even graphic equalizers (as found in mp3 players) can be fun to play with - the only thing you have to look out for is having a pre-amp option to avoid digital clipping.

HRTF/crossfeed solutions are even more plentiful than that (and essentially free too - check media player classic) and sometimes even built into soundcard drivers so you can apply it to all of your system's sounds (e.g. games, movies, etc.) But I think with "upmixing" stereo into surround it does a much poorer job than with simply down-HRTF'ing 5.1/7.1 to stereo for headphones. (Subjective evaluation of course, so YMMV.) You may want to check YouTube here, there are some videos comparing Dolby Headphone / CMSS-3D / THX TruStudio.

Still, the main point of this discussion should be that Tyll has been practicing his question-evading skills very hard as of late. The essential question as to why anyone would want to accept tube-induced distortion instead of having clean - and configurable - digitally-added warmth remains unanswered. But my question why he bothers with measuring IEM-tips, but not headphone-cables (since he claims to hear a difference with those) went unanswered too.

mikeaj's picture

Agreed, for the non-transducer part of the home audio playback chain, the mid-to-high end market has been focusing on the wrong parts: the amps and DACs.

For a while now, we've been able to do both very well, at a reasonable cost. But for the sake of product differentiation and sales, we get all sorts of products with exotic (or sometimes, just plain outdated), more costly topologies, different ways of degrading the sound quality (that's how you can get something to sound appreciably different than a reasonably-cheap reference device), features of little use like balanced drive, and so on. We get false innovations for the sake of marketing.

Maybe it's just for the best to keep using circular wheels instead of trying to optimize octagons--or cram more rare earth metals and boutique components into them.

If InnerFidelity is about personal audio, then what's more personal than tailoring the sound to suit your needs? You can get a lot more mileage out of tweaking crossfeed, EQ, etc. in hardware or software, than switching between one expensive amp/DAC versus another amp/DAC. Or you can take control by adding nothing.

There seems to be less interest in hardware (and software) controls and effects processors than there should be, at least in comparison with interests in more expensive amps and DACs.

Limp's picture

I think the interest in personal sound processing software is rising. In the past one of Cowon's main selling points were their implementation of BBE sound processing, well known and highly regarded as the best way to enhance and tweak the sound in your favour, beyond mere EQ and cross-feed.
Now it's available as an iOS app and getting rave reviews.

Tyll Hertsens's picture
Wolfson is making better DSP hardware for portables as well. We'll likely see more DSP audio manipulation as time goes on. Good stuff!
ultrabike's picture

Wolfson DSP: Sweet! Hope to see developers squeeze the juice out of this little monster.

@Limp: Nice. Didn't know about BBE until you mentioned!

EDIT May 24:
BTW I don't know how I missed this post:

Really looking forward for serious reviews/impressions on those. Portable solutions are really picking my attention.

... deleted the rest to keep things simple :)

Willakan's picture

I was pondering a distortion spectra simulator, as I'll wager 99% of sound signatures that actually exist come from THD and IMD.

The idea would be to let you set the composition of the distortion in terms of harmonics and the amplitude of each harmonic, as well as let the composition of the distortion graduate between three presets at 20hz, 1khz and 20khz: combined with FR and phase manipulation you'd have something which would likely do an alarmingly good job of sounding like the amp you set it to duplicate.

From a sound processing perspective, it wouldn't be that complicated (complexity being very relative, mind you!) but I lack the programming skills.

kixxit's picture

Thank you for the article - I really enjoyed reading your point of view.

If we are in fact attempting to get closer to the original reproduction of a piece of pre-recorded music, why aren't more homes filled with the same gear as found in the studios of the producers who created them? Why don't I have a pair of Genelec or JBL powered speakers? I understand that I don't have the same room treatments as a good studio, but half of the recordings out there (it seems) aren't recorded in one anyway. Do all the studios have gilded amps and exotic wood paneled speakers? Just askin'.

I used to have a subscription to Stereophile. And after a few years of watching the Emperor in his new/newer/newest clothes, I had to end our abusive relationship. Once I read the excuse (don't remember the author) of 'test anxiety' as a case against blind testing, I lost all respect for the publication. Even a sommelier needs to know his stuff. Every year, the highs got higher and the midrange sweeter as if companies really could improve the quality of the music thru exotic gear at a rate of 33% every issue. Blind testing rules the house as far as I'm concerned. If every audiophile stopped testing for "A" VERSUS "B" and instead tested for which one was preferable to the ear, whatever status they so fear losing as "golden ear of the year" they'd gain in honesty. The humility gained in finding out one thinks the Cerwin Vegas really do sound better than the Wilson Sashas would save a lot of people a lot of money and perhaps draw even more people INTO the hobby instead of out of it.

Thanks for letting me vent.

Tyll Hertsens's picture
I absolutely agree that more people should experience blind testing. It's a heck of an eye opener at the start, and as you get better at it, you also begin to put into perspective the magnitude of things. Too many people describe small differences as huge changes.

AGB's picture

From the get go and for the first time in my life after converting to headphone listening, I am using parametric EQ - and I had raised this issue here since last summer. The equipment is half the story and clearly all sorts of equipment at reasonable prices has gotten better. In my home theater system I found a $600 pro stereo amp to better the fancy audiophile amp I used before. One that today would cost maybe $15,000. It gets worse. I bought the $600 amp made in China for $250. Ouch!

Coming from someone whose been around top flight gear for most of my life as a reviewer for one of the known journals, it is embarrassing today to recommend to friends stuff that's over the top up-market that'll become boat anchors soon enough. Yes, a $5000 DAC may sound slightly better than the $500 DAC and should. And a few brands (usually direct internet sold) compete with the $5000 DAC on an equal footing at two thirds or less the price. Ditto for wires. Some sell for $500 and then you find a $200 wire that just sounds better...and so it goes.

It's an embarrassment of riches in the mid and low end, and an embarrassment of foolishness at the top end of this game. I agree that the limiting factor at this time are the transducers and luckily we have a few very satisfactory ones.

And those can be almost perfected with parametric EQ, crossfeed and such. In other words, digital processing will improve just about every heaphone, DAC, amp or whatever. The whole system.

One company, Audiofile Engineering has a beginner's player for extracting iTunes, FIDELIA @ $19, that also has an advanced plug-in and a headphone plug-in, the last two are $49 each. Well worth it.

FIDELIA uses the SAME iZotope resampling used by Amarra and possibly some others. It also has the three band parametric EQ which I use to flatten (to the best of my abilities) the sound at my ears and correct for volume limitations.

Lastly, not everyone can do what I've done: I have eliminated the headphone amp and its wires altogether by going out of the RCA preamp outs on my DAC (which has a preamp built in. A good one!) Obviously, provided that you can do likewise, you can expect a substantial increase in clarity, purity and nuance of tone, dynamics, background quiet and all the other goodies we want to hear from our systems.

All in all, some good ideas here.

Willakan's picture

"...Yes, a $5000 DAC may sound slightly better than the $500 DAC and should..."

Should it? Does it? Really?

You can perform extremely high fidelity D/A conversion with a $500 piece of equipment (DACMagic+, for example). Hell, you can go considerably cheaper than that (Hello NwAvGuy!).

I would put inordinate sums of money on that sounding exactly the same as any other well-measuring DAC when the listener doesn't know what they're listening to. You'd think in four decades of asserting that our ears are capable of hearing parts of sound that we can't measure someone would have managed to do a decent comparison under controlled conditions (not to say that this precludes the possibility of such things emerging, but there is absolutely no evidence at present for their existence.)

Another point against attacks on blind-testing: the burden of proof falls on those making the claim. If they want to attack blind testing, fine: the onus is still on them to find a form of controlled test which does show up their reported differences. The only way out of this logical cul-de-sac is trying to contest the existence of the burden of proof, and that way lies hypocrisy and madness (and giggles)...

The audiophile record for anything approaching proving is pretty lousy: I can find seemingly rigorous studies to support ESP and homeopathy (that were later proven flawed): absolutely nothing to support the ability of human ears to hear the unmeasurable/barely measurable.

lameassphone's picture

I really don't get the point of blind tests, "just hear differences"...

Wouldn't be more accurate if the listener had to point which is better??

AGB's picture

I think some of this conversation-topics depart somewhat from headphone testing and use, but there have been many self-serving arguments in support of both positions: objective v. subjective. Self-serving by the audio rags/reviewers of course, they make their living from it; and by those too, who really don't have much experience with high end audio and can't afford it anyway. I suppose you can read into this whatever you will and surely everyone will be rubbed raw by the mere mention of this hot topic.

More than a few knowledgeable people will tell you that sonic differences between amplifiers running within their linear range will sound close, one to the other. Up to a point this is true and up to a point the ear can be fooled. But surely many of us can hear differences between reasonably well-designed amplifiers given the chance, even if those differences are relatively small, and this is where preferences come into play, tubes v. transistors, single ended v. balanced, which is "better," whatever.

My reply to the strictly objectivist is this: If you can't hear differences, fine, I believe you. Just don't tell others that they can't hear differences, because you don't have their ears, brains, experience, and equipment.

Put into context, some differences have to exist simply because there are different circuits through which electrons, magnetic phenomena and such, time and group delay and such, behave differently. In no cases will the input equal the output because some deviation, distortion, time delay, will exist at the output where there was none at the input.

Whether one can hear these differences some of the time, none of the time, or all of the time is up to the individual's hearing acuity and experience...or the ear can be fooled ALL of the time. Take your pick of positions on this matter, I can argue all of them equally well.

Most of us would agree that we can hear differences between transducers, speakers and headphones. One reason besides they being electro-magnetic-electrostatic-mechanical-acoustically-coupled devices that radiate sound differently, one from the other, we simply believe what we hear. Human beings are wired that way. We believe our eyes, what we see; and we believe what we hear.

No amount of objectivist argument can dispel our existential experience with life. We can intellectually, however, accept that we, our senses, may be fooled.

I'd be first to agree that a good designer can, with today's technology, design a more-than-adequate DAC for $500 more or less, but that DAC will not contain a good preamp with a great power supply. A good engineer should be able to make such a DAC for $1000-1500 (internet sales, not marked up by a street vendor) and provided the preamp can swing adequate voltages, such a DAC won't need an external headphone amp...providing BETTER sound than an equivalent DAC with an external headphone amp and its additional wires.

Possibly more important than any of these issues, as discussed here, is the idea that proper digital resampling will do far more for improving what you hear, than all the other ideas and equipment combined.

This PDF might be helpful to readers:

and more reading material:

Timmy's picture

No, I'm sorry. Whenever it comes up in a discussion, I'll do my best to protect people from being scammed out of their money. It's a shame how some manage to make a living off other people's gullibility - but more than that, is skews the market position and thus harms the few remaining educated and honest market participants too.

Willakan's picture


My assertion is not that you do not hear differences between linear pieces of equipment.

My assertion is that there is a great deal of evidence to show that those differences are products of flaws in human perception and absolutely no evidence at all to show that they are anything else.

I occasionally see responses to this along the lines of that if something makes audio seem better to you, who cares about the mechanism? Unfortunately, the people making this point never actually believe it.

Consider I sell them an "upgrade" to their headphone amp for a small fortune, which is exactly the same as their previous headphone amp but comes in a shinier metal case with a resistor changed so it plays slightly louder at equivalent volume settings. Upon them declaring this a vast improvement over their previous amp, I inform them it is their previous amp, but in a nicer box, and thank them for their money, reminding them that it's their perceptions rather than the actual amp that count.

I can assure you that at this stage they will suddenly forget about all their talk about the subjectivity of audio and get very upset.

On the rest of your post, I don't see the significance of pointing out all the mechanisms by which differences can occur: we can measure far smaller differences than we can hear - ever tried distinguishing 0.002% vs 0.0005% THD?