Harman tweaks its headphone target response

Those of you who follow developments in headphone measurement will know that in recent years Harman, with Sean Olive leading the effort, has been busy investigating and defining the ideal headphone target response – in other words, the headphone frequency response, as measured at the ‘eardrum’ of an artificial ear, that results in a perceived tonal balance preferred by listeners when replaying conventional stereo music recordings. Well, I’ve news of some recent developments on that score.

Prior to Harman’s research there were two schools of thought regarding headphone target response. The first was that it should, not unreasonably, match that of a sound source located in the horizontal plane and 30 degrees to one side of straight ahead – ie where a conventionally positioned stereo loudspeaker would be. This became known as the free-field (FF) target response. Logical as the FF assumption might seem, it was successfully challenged in the 1980s by the work of Günter Theile at IRT (Institut für Rundfunktechnik – Institute for Broadcasting Technology) in Munich, Germany, which identified as preferable the diffuse-field (DF) response, as experienced in a diffuse sound field where the sound has no particular direction. Of the two, the DF response held sway until Harman began re-evaluating the issue from scratch.

When Harman generated its first target response for circumaural (over-ear) and supra-aural (on-ear) headphones in 2013 its most obvious departure from the DF response was a low frequencies, which were shelved up below about 200Hz, thereby mimicking the in-room response of loudspeakers in an acoustically well-behaved domestic space. Since then Harman has generated two further iterations of this response, in 2015 and 2017, in which the LF up-shelving and other features of the target response are similar but modified in detail. Also last year, Harman announced a separate target response for in-ear headphones (insert earphones), which incorporates even greater bass boost.

Now that I have data for the latest Harman circumaural/supra-aural target response, I thought I’d share with you not just the new response but an overlay of all four Harman target responses so that it’s clear how they have progressed. You can see this in the graph below. In the key, OE stands for over-ear and IE for in-ear, although Harman has taken to calling circumaurals ‘around-ear’ (AE), which is both a more accurate translation and a more accurate description than ‘over-ear.' So in Harman-speak, AE equals circumaural and OE (on-ear) is supra-aural. All four responses are normalised to 0dB at 1kHz.

At high frequencies the latest OE (Harman: AE/OE) target response still quite closely resembles the diffuse-field target response although, compared to the 2015 version, the response peak at around 3kHz has reduced in level and moved up in frequency a little to 3.5kHz. Below 1kHz the 2017 target response has slightly increased in level, the 2017 and 2015 responses both being more markedly boosted below 200Hz than the original, 2013 target. The in-ear target response is very similar between 300Hz and 4kHz but notably features even greater bass boost.

Sean Olive explained the evolution of the circumaural/supra-aural target response to me as follows: “The AE-OE target curve evolved over the past four to five years. The first iteration was based on measurements of an accurate loudspeaker calibrated in our reference listening room. It was slightly modified with some method of adjustment (MOA) experiments where listeners modified the bass and treble, and also feedback from various tests with over 500 listeners from USA, Canada, Germany and China.

“The MOA tests led to about a 2dB increase in bass in 2015. In 2017-18, we reduced the treble around 3kHz by about 2dB largely based on feedback from listening tests conducted in Germany, China and USA. This new target curve was validated and tested against 31 different models, and reported in our recent AES Milan paper.

“The MOA tests have told us that the exact amount of preferred bass/treble will vary depending on age, listening experience, gender, and program material. Younger listeners and less experienced listeners generally preferred slightly more bass and treble than older, more experienced listeners. For senior listeners (55+ years old) we found they preferred on average even less bass but more treble than younger listeners. We believe this is related to hearing loss. This is an educated guess because we didn’t measure the hearing of the subjects (except Harman trained ones) and we need to test a larger sample.

“So the final target satisfies the majority of listeners, although it won’t be perfect for all programs and all people. We believe some degree of personalization is necessary to satisfy all listeners.”

When I begin my headphone testing for InnerFidelity, the latest Harman AE-OE and IE target responses will be used, as appropriate, to create corrected frequency responses, together with the FF and DF targets of old. This may seem overly complex but it allows individual readers to decide, on the basis of their own listening to reviewed models, to decide for themselves which target response is most appropriate for them. For example, I don’t generally like the full Harman AE-OE bass boost and find the diffuse-field correction more closely matches my perception of a neutral tonal balance.

COMMENTS
Gooberslot's picture

I wish you had added the DF response to the graph. It would have been interesting to compare.

wiinippongamer's picture

I'm sure the folks at Harman know well the studies of the missing 6db in the low frequencies. The harman target might be the most preferred target, but it's not the most accurate. I use a similar target myself.

KaiS's picture

A common misconception I read very often lately is that it would be sufficient to just copy that curve from the chart to calibrate your measurement system.
That's simply wrong.
You do need to go to Harman's room with your system to calibrate it, no way around that.
The only other way would be to use the exact same system Harman does and get their correction curve (which is not the target curve you see here).

There is one exception: the range down below 800Hz is usually flat (raw data), no matter what kind of (quality) measurement system you use, this can be transferred from one system to the other.
But then, in the low range, it's very important how airtight the seal of the headphones to the measurement system is. Differences here can vary the results by several dB, even more than the Harman target's boost is.

Tonmeister's picture

We measure AE/OE headphones on a G.R.A.S. 45 CA with our leakage-accurate pinnae developed by Todd Welti. We are in the process of moving to use the G,R,A,S anthropomorphic pinnae which have similar properties as Todd's pinnae, and the new GRAS high resolution RA0401 coupler. For in-ear headphones we've been using the GRAS IEC 308 coupler with conical ear canal extender.

So, if you want to duplicate our measurements you can simply purchase the same system. If we traded a few models of headphones we could compare measurements to verify that the systems perform as expected and we are using the headphone placement methods.

There is no need to duplicate the Harman Reference Listening Room equipped with our audio system.

Cheers
Sean Olive

briskly's picture

Has the in-room response at DRP been tested with the new JBL 7 series(LSR705/708)?

Tonmeister's picture

Yes, we are aware of the studies on this phenomena. The more recent ones have largely debunked it attributing much of the differences to errors in experimental methodology..

We did some of our own binaural room scanning studies in a few years ago in cars to binaurally capture and reproduce the audio system through headphones. When listeners could sit in the car and compare the actual car to a recording of it made through headphones, listeners said there was 2-3 dB missing bass even though the signals from the headphones were calibrated to match those produced by the audio system in situ.

What was missing was the tactile / whole body vibration from the seat/door panels, etc . The vibration added about 2-3 dB more bass to the perception of music. When we simulated that vibration with the headphones, the problem of missing bass went away. Without the vibration, adding 2-3 dB bass in the headphones was considered to be a good compromise.

From a technical standpoint, I would define a "accurate "headphone target curve as one that matches the response of an accurate loudspeaker calibrated in a reference listening room measured at the ear drum. That was our starting point. The current OE curve adds about 2 dB extra bass to that.. Whether that sounds accurate will depend on the recording, age, gender, hearing loss, listening experience. We've found very few people who think headphones tuned to the DF sound accurate or neutral. If you think about it, recordings are neither made or typically reproduced in diffuse fields using loudspeakers that have a flat bass at the listening seat. That's why I think it doesn't sound accurate.

KaiS's picture

The weak point on the Harman approach is, you need a non-uniform reference room. But who determines how exactly a perfect reference room has two sound like, especially if it's based on the "living room" idea.
This would mean you have to define every single element of a room+speakers with almost zero tolerance, a much stronger requirement then even recording studios need to fulfill.
I could imagine an approach where free field and diffuse field, each with their own clearly defined equalization, is mixed in the calibration of a dummy head. The result would be reproducible all over the world. Your own reference room could be used as a starting point for the definition of the process.

Tonmeister's picture

I already addressed this above but to repeat: you don't need a Harman Reference Room. Just buy the same measurement equipment. This is what Keith Howard id doing: using same same GRAS couplers and pinnae that we are using so there is a means to compare target curves --or at least a good approximation.

I'm not sure what you mean by a non-uniform reference room. Our room is not atypical of most listening rooms in terms of size and RT60 It's probably a bit quieter than the average room but that doesn't have much influence on the measured in-room target curve. You can read about the room here: http://seanolive.blogspot.com/search?q=Reference+Room

I would argue the loudspeakers and how they are calibrated at low frequencies have more of an influence on the measured response at the ear drum than the room. The loudspeakers calibration process corrected any low frequency interactions between the room and speaker which means the room is essentially removed below 200-300 Hz. Another essential property of the loudspeaker is it has flat on-axis and smooth off-axis response. The influence of reflections on the headphone target curve at higher frequencies was reduced by using 3 spatial averages of the head to minimize acoustic interference. We also smoothed the response in the frequency domain so that the target curve was smooth...

Cheers
Sean

Tonmeister's picture

I wish that comments could be edited but they apparently cannot so I add this paper as a reference to the study I referred to:
The Effect of Whole-Body Vibration on Preferred Bass Equalization in Automotive Audio Systems

http://www.aes.org/e-lib/browse.cfm?elib=15150

Cheers
Sean Olive

_Marty's picture

Hi Sean,

Thanks for taking the time to respond. Sorry to be a bother, I have nowhere near your credentials or experience in audio. But I have done some vehicle audio analysis in the past, so I cannot resist a comment.

Using the interior of a vehicle to gauge listener preference/perception seems like an unusual approach. As you stated, vibration from door panels adds to the experience. But, wouldn't the increased amount of bass come at a price of distortion? After all, door panels do not make the most accurate actuators.

Now I also stumbled upon a powerpoint you posted on your blog, found here. Which leads me to speculate that the test platform might have added vibrations to the headphones/drivers. Was this ruled out? Apologies for my ignorance, I admit that I did not take the time to read through everything.

risotto's picture

Is this target response independant of the ear canal length of the listeners since the peak(around 3kHz) depends on it?

twelti's picture

It assumes typical ear canal length. It is not possible to have a separate target for each person. So, the resonances will move up and down some, but I have to think we adapt to that. It is the overall balance, and lack of unwanted resonances that is important. Also the response at low frequencies is very important and that is below any resonance frequency.

risotto's picture

Does the brain ignore if the peak is at a different position because of individual variation in ear canal length? The ERB(equivalent rectangular bandwidth) at 3kHz is ~ 350Hz. If the difference is > 350Hz, it should be perceived, isn't it?

I always wondered about this since AKG K70x and HD650 have the peaks at different frequencies.

sszorin's picture

Your brain will ignore this treble peak if you [your brain] tell it [to itself] that the peak is not supposed to be there.
Seriously. The first time I used Bayerdynamic T1 for listening I heard a treble peak of about 3dB louder than 'normal' level. I told myself [my brain told itself] that this treble peak should be slightly reduced - and ever since I have not heard it again. My brain simply filters out this extra 3 dB of volume at that particular frequency. Thus I have perfect headphones.

Tonmeister's picture

The Harman Target was originally based on measurements of a loudspeaker in a room using the ear simulator in the GRAS 45 CA. So the resonance of the ear canal is based on the IEC standard. The resonances is the coupler is based on median ear canal centered at around 3 kHz. We then validated our target using over 200 listeners for both IE and AE/OE targets.. Even though the ear canals of those listeners varies in length the target was still generally preferred.

There is an interesting AES paper by Gaëtan Lorho who did some listening experiments on modifications to the diffuse field target curve where the main resonance was set to different center frequencies and amplitudes. The frequency of the ear canal resonance being simulated varied from 1.5kHz to 4 kHz covering a wide range of ear canals. It turned out the critical parameter in the listening tests was not the frequency of the resonance but the amplitude. I

Listeners preferred the DF curve when the 3 kHz peak was reduced from 12 dB to 3 dB. We've tested this target curve in our earlier paper and found it was less preferred to the harman target curve

http://www.aes.org/e-lib/browse.cfm?elib=14966

Cheers
Sean Olive
Acoustic Fellow,
Harman

KaiS's picture

The main problem I have with the Harman target, whatever iteration is referred to, it does not use an exactly defined sound field. In fact it seems you have to go to this worldwide unique single existing room for any calibration.
I wouldn't exactly call this a scientific approach, and the changes of the target over time show that it's more a trial and error thing.

Human beings can separate reception of direct and reflected sounds, measurement microphones, including dummy heads, cannot. The way diffuse or reflected sounds are integrated into the human reception of sound is not yet completely understood and can by no means be numerically specified.
That's the reason why diffuse field correction does not perfectly do the job. The approach is wrong or incomplete.

BTW: usual free field targets (or factory supplied correction curves) are often not referenced to speakers from 30° aside, but from the front. This translates even less to a "headphones sound like speakers" experience.

The theoretically only correct way to do this "speaker to headphones translation" would be binaural simulation of speakers in the room using each individual's HRTF. If you do this the targets doesn't matter, you just have to use the same target throughout the process.
Practically, and it has been done, it's not convincing because of many reasons.
Some of he more important ones are:
You have to add artificial signals ( reverb, room sound) to the music which is undesirable,
You do you need multi-axis head tracking because the human auditorial system relies on small head movements to locate a sound, if you skip this part the simulation will not sound realistic.
You need to exactly measure a multi directional HRTF of each individual person to do this.

My conclusion is: listening on headphones is a special experience (I do not even want to simulate speakers) and to make it enjoyable you cannot skip trial and error selecting your personal best sounding headphones.
If all headphones would sound the same (will never happen) you would not have that option.
Personally I have a comprehensive choice of HQ headphones which sound much more different then I would accept with speakers. Depending on the music I listen and my personal current taste I can enjoy all of them.

Tonmeister's picture

If you really want to replicate the sound field you can read the following papers and build the room. The acoustic properties of the loudspeaker and room are well documented and easy to replicate. I can even send you blue-prints.

1. http://www.aes.org/e-lib/browse.cfm?elib=14873

2. http://seanolive.blogspot.com/search?q=Reference+Room

Why did we make modifications of this target through "trial and error"? For several reasons:

1. The psychoacoustics of listening to stereo music through headphones versus loudspeakers in a semi-reflective room are different. There is no way you can arrive at a headphone target response simply based on a one-to-one measurement of a loudspeaker in a room. It is a good starting point but it will not sound ideal for reasons I think you already know. . Perception of bass is one example already addressed above. This is why we had to do significant tweaking of the target curve based on controlled listening tests.

2. Circle-of-Confusion Issues: Until the recording industry has meaningful standards that define the performance and calibration of loudspeakers, the program material is a huge nuisance variable. For this reason, a single target curve based on a measurement of a playback system will not satisfy all programs.

3. In_ear vs. AE-OE Target Curves: It became clear that the same target curve for AE-OE headphones does not sound correct for IE headphones.. When you plug your ear canal (occluded ear) with an IE headphone the acoustics and perception of sound are fundamentally different. It turns out listeners prefer about 4 dB more bass with occluded ear versus non-occluded. The reasons for this are not exactly understood but some possible candidates are occlusion-effect, and increased physiological noise.

I agree with you that the Harman Target Curve cannot satisfy everyone but our validation studies indicate it is generally preferred to the 31 other headphones we've tested for most listeners. Beyond that some form of personalization is desirable.

twelti's picture

I think you might be over-thinking the Harman target curve. It is not claimed to exactly reproduce some mythical perfect reference sound field. It is simply a curve which will generally be preferred by most people if used (with repeatable and standardized measurement method) as a target for headphone design. I would point out that the curves shown are exactly what was used in the listening tests. If used as a target for design purposes, we would normally use a smoothed version. Smoothed at 1/3 or 1/2 octave. Anything above 10 kHz will have some uncertainty due to measurement difficulties, and difficulties with the virtual headphone technique. Fortunately the most important frequency range for subjective preference is below this.

KaiS's picture

First I want to say that I appreciate your work and it's very interesting that someone researches in that field, decades after Guenther Theile introduced the controversial diffuse field headphones equalization.

A dummyhead's HRTF is extremely directional by nature.
The soundfield in your reference room is not directionally uniform too, e.g. reflections coming from the back or the sides have different frequency responses then signals from the front. If you now use the dummyhead microphone for measurements in your room the result is unpredictable.
Examples of clearly defined, uniform soundfields are freefield, diffusefield and pressurefield. These are uniform, controllable and reproducible. A "living room" with a stereo speaker setup is not.

Here is where some questions arise, how was your reference room calibrated:
What measurement microphone was used?
How was it placed and angled?
What signals and measurement arrangement did you use for calibration, sweep/stepped/wobbled sine, correlated or uncorrelated pink noise, TDS chirp, or ...?
Did you calibrate for each speaker individually?
What was the rooms target response?
Else...?
Did you use the same setup for the dummyhead's measurements?
How did you deal with the fact that you have two speakers and two (dummyhead) microphones?
I did not find those mentioned.

You partly work around irregularities by averaging several measurement positions and applying 1/3 or 1/2 Oktave smoothing to the result.
But this limits the usable resolution of measurements done with the system.

And here is where my concerns start:
you set new standards for headphone measurements, but I did until now not find mentioned the limitations of this new model (thank you so far for your statements above).
People start slavishly judging headphones based on the Harman target related measurements, taking it as absolute measure.
Some even use it completely wrong by just applying the curve on any system they have and things like that.
Considering the wide spread of your work I think you owe much more "education" and clear statements to the public, outside AES papers.
E.g. Innerfidelity should give some room for this.
Most people cannot go beyond "cookbook" knowledge. So there should be a clear list of dos and don'ts from you to avoid a widespread misinterpretation.

Finally: I am curiously waiting for correctly done measurements on known headphones, so practical results will show how far these correlate with my (and other's) experience.
Did you make some measurements public?

twelti's picture

Thanks KaiS for your comments and questions. Have you read "Listener Preference for Different Headphone Target Response Curves" AES 134, Rome Italy 2013. This has some of the details you are asking about. May I suggest you read that one and then pose any questions still unanswered? I may have to dig a bit to find some answers, as it has been 5 year or so, but I'd be happy to discuss.

Jim Tavegia's picture

I am having my hearing tested on the 16th as I know I have severe tinnitus and much hearing loss over 5khz. These are the results of 6 years of being in the Army and weapons ranges and being 71 in August. There is no one pair of headphones that will fit everyone and their preferences. Auditioning is critical.

My go to cans for my recording studio are my 2 pair of AKG K-271 (sealed) which for most people will seem bright, just not to me. My listening cans are my AKG K701s. I also own a pair of AT 50X and 40X, but due to my reduced HF hearing sound too bass heavy to me, but for the money I think most people with good hearing would like them. I gave our church my two pair of Sony 7506's as they are just not SOTA any more. I use a pair of Sennheiser HD-280's om my Yamaha digital piano which are fine for $99. I also like my very old Grado 80's which I have always recommended for my older friends based on price and being open-backed. You have to add the larger earpads to make them comfortable.

I will add two more pair of AKG K-271s for performers who come to my home studio to do some recording. If they find them too bright they can use the AT's I have.

There is no way I would spend over $200 on a set of cans without an audition first, meeting a target curve or not. Our hearing accuracy is a bigger factor.

Phoniac's picture

No mass-produced can will ever compensate your personal hearing curve (Army, 71...). Why didn't you go the most obvious and much easier route: EQ?

Johan B's picture

How can the IE curve have such a sharp fall off (Twice)? How can this be influenced without dampening? Over 15Khz nothing matters?

zobel's picture

It seems to me that the curve produced and shown here is fairly representative of what an averaged listening group, without too much hearing loss will consider the best overall presentation of SPL/Frequency, and probably for a good average listening level......When measuring with the same rig, of course.

The next step; chart the difference curve between the measured performance of headphones,(with this rig),and the best updated curve from Harmon. That would ideally give a flat line, if the measurement matches the generalized target curve. After all, isn't that what we want to see?

Tonmeister's picture

Thanks for the appreciation! You are correct: after a raw measurement has been corrected with the Harman Target Correction, a flatter curve is generally related to more preferred sound quality based on a large sample (n = 130) of trained and untrained listeners.. Below is a link to a slide from our latest AES Milan paper showing the relationship between deviations in dB from the Harman Target affect its preference rating.

The 31 headphones tested were categorized into four groups (Excellent, Good, Fair, Poor) based on their preference rating in a controlled listening test. In each category we show the average curve of those headphones (Blue) versus the Harman Target (green) and the error response curve (Red). The more the error response curve deviates from a flat line, the less it was generally preferred. The frequency range in which the deviations occur and the slope (dotted line) of the error curve also gives you a clue as to how the headphone sounds (ie. bright, dull, boomy, etc)

https://pbs.twimg.com/media/DeYs7HQW0AEYGkS.jpg:large

Cheers
Sean

sszorin's picture

I do not understand this - you gave those people doing the test headphones which have substandard, even grossly substandard, presentation of sound and you expected them to evaluate the quality of the audio signal, approximating Harman curve shape, fed into those headphones ?
If particular headphones have steeply rolled off treble or one note bass or if they have a volume hole in the middle frequencies then they are utterly useless as a tool for evaluation of an audio signal.
And another thing, what were the credentials of people doing this audio test ? I would say 95% of people do not care at all about audio fidelity / high fidelity, most of them even do not know what these words mean.

zobel's picture

Do you think that since all the excellent and good rated headphones in your research show less bass than the Harmon curve would indicate as best, could it be possible that the Harmon curve seeks more low bass response than what would be considered flat, or at least, preferred?

Tonmeister's picture

The way I interpret this is that the amount of bass below 50 Hz is not as critical as how accurate it is above that frequency. The critical area seems to be between 100-500 Hz where many headphones in the fair and poor sound category deviated further from the target than the headphones in the excellent and good category.....

zobel's picture

What headphones come the closest to a flat line as their difference curve to the Harman curve?

DaveinSM's picture

I LOVE informative, interesting posts like this. Tyll’s original investigation and explanation of the Harman response curve was one of my favorite entries. This one is great and chock full of good information. Off to a great start and keep up the good work!

mitchco's picture

Thank you Keith and Sean for the latest iteration. I personally appreciate Harman's research including the history of the Harman target curve.

For loudspeakers, I use the Harman target curve starting at 20 Hz with a straight line to -10 dB at 20 kHz. Sounds neutral over a wide range of music to my ears. It is a great starting point to hear what neutral sounds like, and for some, a destination. I can see how that research translated into a headphone target curve, with some variability on the bass.

NAD HP50's are arriving tomorrow and excited to hear if they will have a similar neutral response as my speakers. Tyll's measurements says it is quite close to one of the Harman target curves - should be fun.

Keep up the great work!

Mitch

mariscosyketchup's picture

+8db under 100HZ? That's beyond low-fidelity, it's Fostex TH-900 bass boost level...that listener panel may be used to Best Buy boomboxes.
For speakers the B&K curve is way better than the Harman, for headphones, +2db bass boost under 150hz is perfect, more bass above that just clouds the mids if the mids are at the correct level.

Overall, I'm dissapointed because this curve promotes clouded mids and overly boosted bass.
And no, I'm not a deaf 80 year old person, I'm in my mid 20s and with healthy hearing.

briskly's picture

I do think this misses the point.
For speakers, saying that an ideal target exists is much like saying there is an absolute ideal loudspeaker directivity and room, and that all others are varieties of inaccurate. A more ambitious goal than any study I know of. Integrated over a sufficiently long time interval, the in-room response will be augmented by sound reflections the room feeds into the listening position. In Harman parlance, these are the first reflections and the sound power.

As for the bass shelf, the Q and frequency points were selected to reflect a slightly high subwoofer crossover point, as well as limit the midrange coloration. Q can be raised and frequency lowered to minimize this further. And of course, the result is only a mean of preferences with a handful of test tracks. A different set of test tracks could yield a less aggressively bass boosted preference. No one says that you have to like what someone else does either.

twelti's picture

The important thing is the shelving filter, that keeps the low end from getting boomy. Your opinions, such as "for headphones, +2db bass boost under 150hz is perfect" are your opinions, not universal truths. Our research is based on the preferences of MANY people, not one. Within that group, there are certainly different opinions, but we have to take an average to get a good target for the rest of us.

sszorin's picture

@ Low-fi bass boost : "+2db bass boost under 150hz is perfect, more bass above that just clouds the mids.."
Not exactly. That would depend on the quality and ability of headphones. If they have great resolution and dynamics/speed then bass frequencies stay in their place and do not flood into mid frequencies. I have Audio Technica W3000ANV which, according to FR graph, have about 5dB compensatory bass boost to deal with the perceived general headphones' bass deficit and the middle frequencies are not interfered with at all, they are exemplary clean. Because of this ability W3000ANV sound perfectly balanced.

Tonmeister's picture

As our studies have shown the amount of preferred bass below 100 Hz is highly dependent on program and the listeners' age, experience, and gender. Averaged across all listener the preferred bass for AE/OE headphones was 6.4 dB at 50 Hz. For a 45 year old experienced male the preferred bass was 4.3 dB which is closer to what is preferred for a loudspeaker in room.

For a 25 year old experienced male it's around 6.1 dB..

I already made the point that this variance in program and personal taste is a good argument for tone controls and personalization.

Since the bass boost begins below 150 Hz it doesn't promote or cause clouded mids. Most female and male voices have fundamentals that fall above this range and are not adversely affected.

Cheers
Sean Olive
Acoustic Research Fellow

Leffen's picture

"“The MOA tests have told us that the exact amount of preferred bass/treble will vary depending on age, listening experience, gender, and program material."

The classic story in this regard is when you're young, you boost bass and treble because it sounds more "hyper real", but as you age, you realize that that is artificial and getting in the way of the natural balances of the mixes. And you're better off just turning the music up, or doing nothing at all. Or making really subtle adjustments to improve the balance.

Ideally we want transparent reproduction with transducers, and then the ability to EQ or effect it as we please. Speakers should be tuned to be neutral for people with full hearing, and should be tuned to the preferences of wiser listeners who care about and listen for neutrality and "the tonality of real life".

For those with hearing loss, we can then give them personal corrective EQ curves and processing.

For teens who are having their early listening experiences and are lost in the dreamy beauty of it all, we can give them their own EQ's and processors if they want to make things sound more wild as they please.

That's the problem with those MOA tests.
I want an MOA test that only involves subjects who are mastering engineers or golden eared product designers or audiophiles.

I wish we had gotten Bob Katz's ideal headphone curve taken down before he left IF.

twelti's picture

We DO have some data showing the differences between young/old, and more/less listening experience. You can use that to modify the basic target curve.

sszorin's picture

Yes, what is happening with Bob Katz ? We need him.

Quizel's picture

Could you by chance make the new graphs with transparent backgrounds-instead of a opaque white or random color?

I'm guessing that's not a simple request as I see it no where. My hope is to one day be able to superimpose graphs of my choosing. That may need a completely custom user interface though... Perhaps it could be as simple as selecting the data sets one wants and hit the "draw all graphs" button. Providing the raw data of every recorded measurment could also work but that would most definitely be messy to look at for the average user -> even myself.

Hifihedgehog's picture

instead of allowing open dialogue, this new editor is sterilizing any comments from users who may have some advice and when he does comment, he chooses to be closed minded. Just see the article immediately after this one, where commenting has since been disabled and all comments (approximately 20) that do not meet his criteria have been deleted.

amadeogt's picture

...on that same post, because I actually enjoyed it (hadn't heard about TrueFi, and decided to try it because of the post). Unfortunately, comments were disabled.

Rafe Arnott's picture

If by "advice" you are referencing toxicity, then yes, that does not meet my, or anyone's criteria for discussion.

"Close-minded" I am not, aware that this site has been allowed to descend into mudslinging, yes, I am aware of that.

Comments moving forward will be moderated to maintain positivity and focus, not a place where people are concerned about being ridiculed for asking a simple question.

roscoeiii's picture

Can anyone point me to a good resource on why In Ear Curves differ so much from the other Harmon curves on both ends of the spectrum?

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