Dr. Hans W. Gierlich On The Future of Audio Quality Testing: More Than Just Frequency Response
Apr 30, 2023 at 12:05 PM Post #31 of 71
Like instead of enjoying grandma’s baking/cooking, we are trying to decipher her recipes to determine what it tastes like. It’s literally the same thing.
All depends on Grandma's cooking....and which epoch one is thinking of.... although I don't have any grandchildren (yet)....most of my friends do so. But if I ever do it will be Granddad's cooking. : )

A live recording in a hall will sound different from a studio recording done in an anechoic chamber.
The ideal headphone would be, and honestly most accomplish this already IMHO, is that regardless of the music we clearly hear that it is "a live recording in a hall" or a "studio recording...." or any other effect added....some just accomplish it better than others.

So what is the right reproduction for these two extreme cases?
They are not extremes just different recordings and any competent playback equipment will just reproduce the sound waves to hopefully recreate the illusion.

All very subjective and very much recording, music and person dependent.
Absolutely... I guess what theoretically is being discussed is just giving hobbyist or potential headphones purchasers a better tool as to what to expect and if the manufacturer has achieved their goals.

Can we or shall we even evaluate the immersiveness for a transducer, a feature which should be mostly inherent in the recording?
All good questions....for the audio hobbyist computers have opened up a can of worms and with digital music files anything is possible........


They say ignorance is bliss. I’m slowly beginning to realize that they were probably right.
But we still know what we like. : )
 
Apr 30, 2023 at 4:07 PM Post #32 of 71
Dr. Hans W. Gierlich On The Future of Audio Quality Testing:
More Than Just Frequency Response



Is looking at a frequency response plot enough to tell you whether or not you'll like a particular headphone? Can someone equally like two headphones that do not sound alike? Is measuring eardrum pressure as a function of frequency from one side of a headphone enough to know how that headphone sounds? We had questions.

In this exclusive interview, Jude sits down with Dr. Hans Gierlich of HEAD acoustics to discuss the innovative MDAQS algorithm, and to ask those questions. MDAQS is a new approach to measuring the quality of audio in a more comprehensive way -- in a way that takes us beyond the eardrum, beyond just frequency response. This is a fascinating discussion about a technology we believe will help shape the future of audio quality measurements.

Referenced videos (below):

Nice to see some professional attempts in quantifying audio quality with fairly agreeable categories.

Thanks for sharing Jude!
 
Apr 30, 2023 at 4:19 PM Post #33 of 71
I think I understand the potential need for measurements but at the same it is kind of sad (I’ll resist using “pathetic”) that the magic and emotion we felt when we were kids listening to a transistor radio or Walkman has transformed into this type of overthinking/over analyzing. And I’ve become immersed in it, like someone who semi-voluntarily left the wonderful atmosphere of the beach and dived headfirst into a cesspool. I lost my sense of original purpose.

Like instead of enjoying grandma’s baking/cooking, we are trying to decipher her recipes to determine what it tastes like. It’s literally the same thing.

They say ignorance is bliss. I’m slowly beginning to realize that they were probably right.
MDAQS is trying to unlock the riddle of how and why we enjoy a certain sound. The idea here is the more tools you have results in having more power. I personally love the idea that they are trying to zero in and establish timbre as a value. Will it mean that headphones will be better, that remains to be seen, but we will understand the process of headphone listening better I think.
 
Apr 30, 2023 at 6:18 PM Post #34 of 71
The ideal headphone would be, and honestly most accomplish this already IMHO, is that regardless of the music we clearly hear that it is "a live recording in a hall" or a "studio recording...." or any other effect added....some just accomplish it better than others.

They are not extremes just different recordings and any competent playback equipment will just reproduce the sound waves to hopefully recreate the illusion.
Extreme in the sense that one has a natural hall effect, the other one depends on how much freedom the mixing engineer had, which can also be very dry (though unlikely). Some HPs for whatever reason (in cup resonance, distortion etc.) has some added hall effect. Does this really make it any better and should it really be represented as "good" ignoring the distortion, or bad as it is not faithful to the recording? Do we really need a common likeability figure? I don't know. At least I don't believe in a single number evaluation.

For timbre, FR didn't really fail me until now. Especially in the mids any warmth or wonkiness can be easily seen on the FR, especially in relation to the lows. You won't have pushed up low mids but still have crystal clear, not warm vocals, you won't have a FR with multiple dB hills and valleys in the mids but not have a wonky tonality.

In any case, plug-ins like this already give excellent results in creating a larger space:

https://unitedplugins.com/Expanse3D/

190.1280x720-fit.v1619105934.png
 
Apr 30, 2023 at 7:56 PM Post #35 of 71
For timbre, FR didn't really fail me until now.
We may be confusing things...timbre for me is the the ability to distinguish the oboe from the clarinet..that's pretty difficult IMHO looking at a FR chart, spectral analysis as I mentioned previously, maybe.

In any case, plug-ins like this already give excellent results in creating a larger space:
again....the goal of the audiophile is to recreate the illusion of the "original" recording/space....not to enhance or degrade it.


But I regress...
Is looking at a frequency response plot enough to tell you whether or not you'll like a particular headphone? C
...and to reiterate....from past experience as music is a complex waveform...maybe a ball park assumption...but not really

But a clearer picture, if possible, of "timbre, distortion and immersiveness" in conjunction with the frequency response would be invaluable.
I'm not sure how we can go about it or if it's even attainable but an interesting endeavour all the same.
 
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May 1, 2023 at 5:09 AM Post #36 of 71
We may be confusing things...timbre for me is the the ability to distinguish the oboe from the clarinet..that's pretty difficult IMHO looking at a FR chart, spectral analysis as I mentioned previously, maybe.
I think it is not in the context of listening to music via a HP. Yes, it is highly unlikely to guess the timbre of the instrument just by looking at the instantaneous frequency domain information of the input signal. This, anyway, has nothing to do with frequency response of a HP. FR gives information about how a system transforms the input signal, whereas for the timbre "definition" we are more concerned with the input signal. So for the HP, the issue is if the timbre of an instrument can be preserved, and that can often be guessed for an experienced person that has been trying to make a relation between what he is hearing to the FR of HPs. So, for me, in our context, it is whether and how much it distorts the sound of the original audio.
again....the goal of the audiophile is to recreate the illusion of the "original" recording/space....not to enhance or degrade it.
This is the usual audiophile claim. I agree with that, as also my personal goal, but in the end it is how much people enjoy what they are listening. Many audiophiles claim to have the same goal but then use HPs with wildly varying responses, a ton of different amplifiers that inflict different forms and amounts of alterations to the signal, even cables, DACs, even try different microSD cards and write about how it affects the sound stage, depth, height etc. Many of those things are at the psychological level, but that is for another discussion. Then I come with the suggestion "why not just use a plug-in to alter the sound in a way you like?" and mention this plug-in. Then the response is "I don't like DSP, I rather use 5 different amplifiers and pair them with 10 different HPs and find the sound I like. This way it stays the way as artist intended". Does it make sense? Not for me, but many claim it does.

Anyway, I guess I am done for now before one of those old discussions start.
 
May 1, 2023 at 1:10 PM Post #38 of 71
Other parameters are not negligible, but they are still secondary to Frequency Response
What is the first thing I do?
I put the model on my head, then my ear tells me...do I like what I hear?
What bothers me about in the tonal performance?
And if not much bothers me, only then do I start to listen more closely to find the strengths and weaknesses in the performance
(Resonances,distortion,level stability,accuray/precision of the performance,timbre,speed,impact etc etc)

NOMAX

PS.lol
 
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May 1, 2023 at 3:30 PM Post #39 of 71
I think we are all agreeing on the same thing that FR is important....but
Is looking at a frequency response plot enough to tell you whether or not you'll like a particular headphone?
Jude brought up a number of examples of just why FR may not be enough and on those premises and more I do agree with him.
The discussion comes down to not only using physical measurements but also perceptual..or as mentioned "beyond the ear drum"....can those parameters be measured and displayed.

I put the model on my head, then my ear tells me...do I like what I hear?
Up until now I believe that is indeed what we all do, or at least most of us.... but if we are able to the utilize the "innovative MDAQS algorithm" prior to even trying the headphones, which many cannot, that in conjunction with FR, I believe would be invaluable to make an educated purchasing decision.
I guess the biggest concern would be as to how the final MDAQS algorithm is derived and if so is it without bias.
 
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May 1, 2023 at 8:22 PM Post #40 of 71
The Future of Audio Quality Testing will end when John Atkinson retires. Not kidding
 
May 1, 2023 at 8:32 PM Post #41 of 71
Trying to reproduce a correct FR is irrelevant as recording studios are practicing the circles of confusion into which (monitoring) replay is not standardized. This is why every recording sounds different. Still a part of realism can be derived from sound recordings, but it will never be perfect as the original sequence of events was lost in time.
 
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May 2, 2023 at 5:54 AM Post #43 of 71
Trying to reproduce a correct FR is irrelevant as recording studios are practicing the circles of confusion into which (monitoring) replay is not standardized. This is why every recording sounds different. Still a part of realism can be derived from sound recordings, but it will never be perfect as the original sequence of events was lost in time.
To be fair, nobody is trying to create a "correct" FR for a HP, but rather a guide. For example, Harman Target is a guide for neutrality, and it is mainly done for natural sounds and does not try to compensate the harsh black metal guitars, or provide ear pounding techno beats. Anyone that does not care about the natural sounds, timbre, vocals (electronic music, death metal etc) will not care about the multi dB wiggles in the mids, but these will have a huge effect in for the acoustic instruments and vocals. Harman Target gives us a ballpark figure for neutrality, but it does not tell if you should like it or not for a particular recording that has specific "likeability requirements".

I see often a metal listener popping up in a HP thread (for example, DCA Stealth) preaching about how bad that HP is and how great another HP is, mostly talking about the bass performance, whereas users of that HP have different expectations.

We all need to understand that what we like and expect differ significantly with recording, our anatomical features, our listening experience, and even our culture. For example, chromatic scale is seen to be "the" backbone of the music theory, but for eastern music (e.g. South Asian, Southwest Asian) the scale structures and the theory differs quite a bit and they divide that 12 notes even into finer notes, which might sound incorrect or inaudible for the western ears but would be perfectly fine for people that grew up listening to music based on that theory. Same thing for the rhythm. Even most experienced western musicians (like Marcus Miller) will struggle with the rhythmic structures of North Africa, India or Turkey. On the other hand, western music has wonderful harmonies and orchestral music, which by the way will create different listening expectations.

So, there is nothing right but there are guides that sound "about right" in a particular context. Harman Target FR (which itself has multiple versions with small tweaks) is such a guide that serves as a common reference for the industry for a common vocabulary.

Science priests are not gonna like this...
Did you watch the same video as I did? Because he takes the scientific approach to the next level, trying to quantify even the perception with even more number crunching?
 
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May 2, 2023 at 6:01 AM Post #44 of 71
To be fair, nobody is trying to create a "correct" FR for a HP, but rather a guide. For example, Harman Target is a guide for neutrality, and it is mainly done for natural sounds and does not try to compensate the harsh black metal guitars, or provide ear pounding techno beats. Anyone that does not care about the natural sounds, timbre, vocals (electronic music, death metal etc) will not care about the multi dB wiggles in the mids, but these will have a huge effect in for the acoustic instruments and vocals. Harman Target gives us a ballpark figure for neutrality, but it does not tell if you should like it or not for a particular recording that has specific "likeability requirements".

I see often a metal listener popping up in a HP thread (for example, DCA Stealth) preaching about how bad that HP is and how great another HP is, mostly talking about the bass performance, whereas users of that HP have different expectations.

We all need to understand that what we like and expect differ significantly with recording, our anatomical features, our listening experience, and even our culture. For example, chromatic scale is seen to be "the" backbone of the music theory, but for eastern music (e.g. South Asian, Southwest Asian) the scale structures and the theory differs quite a bit and they divide that 12 notes even into finer notes, which might sound incorrect or inaudible for the western ears but would be perfectly fine for people that grew up listening to music based on that theory. Same thing for the rhythm. Even most experienced western musicians (like Marcus Miller) will struggle with the rhythmic structures of North Africa, India or Turkey. On the other hand, western music has wonderful harmonies and orchestral music, which by the way will create different listening expectations.

So, there is nothing right but there are guides that sound "about right" in a particular context. Harman Target FR (which itself has multiple versions with small tweaks) is such a guide that serves as a common reference for the industry for a common vocabulary.


Did you watch the same video as I did? Because he takes the scientific approach to the next level, trying to quantify even the perception with even more number crunching?
I agree with the guide part in use of a FR graph understandIng, except I have to disagree with different (music) listeners responding to timbre or scale replay? Everyone simply has preferences, which comes out different choices and opinions. Maybe certain music utilizes different aspects of playback, but?

Somehow some think there is a perfect DAC/Amplifier/headphone tone which is correct, when it is irrelevant due to recordings not being standardized.

But the best part of this technology is they are making FR almost secondary to the individuals comprehension of timbre. And even with timbre being joined at the hip of FR, it may be the key to why we like different FR playbacks?
 
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May 2, 2023 at 9:14 AM Post #45 of 71
Somehow some think there is a perfect DAC/Amplifier/headphone tone which is correct,
Neutrality can be measured so theoretically we can have a perfectly correct system with regards to the DAC and amplification, headphones though, like speakers and the room are the Achilles heel in the chain......and will probably never will be perfect.

when it is irrelevant due to recordings not being standardized.
....over the years I've seen many gear their system or least try to..to perform the same with all recordings so that everything, regardless of its origin, adheres, sounds homogenized to their preferences. Voices have to be intimate, everything needs to be smooth (lifeless in my books), no harshness, always deep bass etc, etc.....EQing (Audio Photoshoping) the hell out of the original recording....no wonder they're constantly chasing systems.
(EQ definitly has its place but that is for another discussion nothing to do with the MDAQS algorithm )

But the best part of this technology is they are making FR almost secondary to the individuals comprehension of timbre. And even with timbre being joined at the hip of FR, it may be the key to why we like different FR playbacks?
That will be a godsend but FR is probably still the starting block and I was thinking about this the other day with regards to the HD820. I've quite recently got to really like this headphone, which was originally dismissed right at the starting block, including myself, by many just from the published FR graphs.
Seriously though, the answer is right in front of us, just look at the headphone. How do we measure with a standard FR measuring system something that is all rather physically different and has been purposely designed, inside and out to create a non standard headphone experience by manipulating, redirecting the soundwaves before they reach our inner ear. If one relies on the The Harman Curve "the optimal sound signature that most people prefer in their headphones" to make you happy you are out of luck!....personally I prefer the Diffuse field equalization.....but maybe, possibly, incorporating the MDAQS algorithm (if it's feasible) to show timbre, distortion and immersiveness, all which IMHO the HD820 do rather well, will.
 

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