The Need for Objective Metrics in Audio Reproduction

[Sal1950]

Agreed. Sal, not certain what you mean by "run a DR14 on every file..." ... may have missed something in translation, or perhaps I'm having another T Bone Burnett moment ...

Technobabble, the first half of the terminal command to create the dr file. dr14_tmeter

[sal@localhost Mark Chesnutt - Your Room (HiRez)]$ dr14_tmeter
/media/SDA11/CD/Mark Chesnutt - Your Room (HiRez)


------------------------------------------------------------
> Scan Dir: /media/SDA11/CD/Mark Chesnutt - Your Room (HiRez)

Blame It On Texas_2_0 STEREO_FLAC.flac: DR 13
Almost Goodbye_2_0 STEREO_FLAC.flac: DR 12
Bubba Shot The Jukebox_2_0 STEREO_FLAC.flac: DR 12
Goin' Through The Big D_2_0 STEREO_FLAC.flac: DR 13
Gonna Get A Life_2_0 STEREO_FLAC.flac: DR 13
I Just Wanted You To Know_2_0 STEREO_FLAC.flac: DR 13
It's A Little Too Late_2_0 STEREO_FLAC.flac: DR 12
It Sure Is Monday_2_0 STEREO_FLAC.flac: DR 12
Old Flames Have New Names_2_0 STEREO_FLAC.flac: DR 13
Ol' Country_2_0 STEREO_FLAC.flac: DR 12
Rollin' With The Flow_2_0 STEREO_FLAC.flac: DR 13
Thank God For Believers_2_0 STEREO_FLAC.flac: DR 13
She Never Got Me Over You_2_0 STEREO_FLAC.flac: DR 13
What A Way To Live_2_0 STEREO_FLAC.flac: DR 12
Too Cold At Home_2_0 STEREO_FLAC.flac: DR 13
DR = 13

- The full result has been written in the files: dr14.txt
- located in the directory:
/media/SDA11/CD/Mark Chesnutt - Your Room (HiRez)

Success!
Elapsed time: 22.59 sec
[sal@localhost Mark Chesnutt - Your Room (HiRez)]$

 

[h.g.]

Subjective. Having been tested that way, I can tell you as the levels get borderline, I start to second guess myself in answering if I hear or don't hear the stimulus. So just testing me alone a second time may give different results.

Why is that a problem? Do you consider audibility thresholds to be fixed and/or measurement to be free of measurement error?

If you could make a true measurement that does not rely on my judgement, then yes, that would be a measurement . Blood pressure or heart rate are such examples.

If I asked you to measure your heart rate by feeling your pulse while watching a clock and then tell me what it was would that be a true measurement or a subjective one?

 

[TBone]

Oh the Bonnie Raitt was really a shame.

Out of curiosity, I measured my only BR album, Nick of Time 1998 CD (591268)
DR: 13/12/13/12/14/12/13/12/14/12/13.

I think the DR value is raising public awareness quite a bit. Yet, bothersome is the fact it has had absolutely zero effect on how mastering is done. Recent recordings, not re-issues, show very nearly universal lack of dynamic range. People who use mastering services get back slammed to the max results even while asking for "go easy on the compression please". Soon most recordings will be able to be accurately described as having both decibels of dynamic range.

Yes, ironically: while the audiophile industry endures endless debates/reviews concerning formats, tubes, SS, wires, adc, dacs blah blah blah in the forever ending ghost like search to attain "superior" sound quality ... our music/sources are being mastered using single digit DR values.

(big sigh)

 

[amirm]

Why is that a problem? Do you consider audibility thresholds to be fixed and/or measurement to be free of measurement error?

Let's go through a simple scenario. You play two files for me which have proven audible differences. I hear that audible difference just the same. But then worry that you may be tricking me by playing the same two files and that the difference I heard may be imagined and I declare the two files the same. In other words, I heard one thing, but voted another. A measurement does not make these mistakes because there is no human in there applying judgement.

This makes it challenging to find small differences in double blind tests. Trained listeners are more immune here as they are able to zoom in and identify differences better but still are subject to vagaries of being human.

Our professional audio measurement systems are far better than our listening ability (in what they measure) so the error there is of little practical consequence.

If I asked you to measure your heart rate by feeling your pulse while watching a clock and then tell me what it was would that be a true measurement or a subjective one?

I am not a doctor so don't know the accuracy of an unskilled person performing such tests depends on some kind of judgement. If you do then you can apply the above to it and figure out if it is subjective or objective.

 

[amirm]

Giving a recent example, Bruce B played a 3-track old recording mixed down to two tracks and ask me from mastering point of view, what is wrong. I immediately heard that the vocal was too low level relative to the band. I wanted to say that but thought maybe he is after some other aspect and said I don't know as to avoid risk of saying something and be wrong. Of course then he tells me that the issue was exactly what I guessed! An instrument showing the relative level of the vocals relative to the band would not make such a mistake.

 

[AJ Soundfield]

I am not a doctor..

...dammit Jim

 

[TBone]

hehehe, funny to the Bones.

 

[Sal1950]

Out of curiosity, I measured my only BR album, Nick of Time 1998 CD (591268)
DR: 13/12/13/12/14/12/13/12/14/12/13.
Yes, ironically: while the audiophile industry endures endless debates/reviews concerning formats, tubes, SS, wires, adc, dacs blah blah blah in the forever ending ghost like search to attain "superior" sound quality ... our music/sources are being mastered using single digit DR values.
(big sigh)

Truer words never spoken. If the audiophile community put half as much effort and $ into finding ways to pressure the major labels into releasing better sounding recordings, as they do over $40,000 speaker cables, we might actually be making real audible progress. The labels are thrilled over the extra bucks they are making selling HDA files at inflated prices while at the same time putting crushed, dynamically crippled sound in them.

 

[TBone]

If the audiophile community put half as much effort and $ into finding ways to pressure the major labels into releasing better sounding recordings, as they do over $40,000 speaker cables, we might actually be making real audible progress. The labels are thrilled over the extra bucks they are making selling HDA files at inflated prices while at the same time putting crushed, dynamically crippled sound in them.

well, problem is, as audiophiles, we're a complicit bunch. I've purchased far too many sucky pressings, in various formats. Today, silly magic pebbles, deep freezing, quantum bullshit, or justifying $40K cables, these are now considered the audiophile norm. Worse, our hobby is currently being presented/represented by "hack" reviewers claiming on Youtube that some flavour-of-the-month product is "the best ever" because "it pops", thnking us audiophiles are clapping our hands in unison, like seals at a circus.

(deep breath) I digress.

 

[Sal1950]

(deep breath) I digress.

ROTFLMAO

 

[AJ Soundfield]

If the audiophile community put half as much effort and $ into finding ways to pressure the major labels into releasing better sounding recordings, as they do over $40,000 speaker cables, we might actually be making real audible progress.

The true irony is the technology has existed for quite some time. But the shepherds and pied pipers know their crowd...

 

[Blumlein 88]

The true irony is the technology has existed for quite some time. But the shepherds and pied pipers know their crowd...

Really wish to know a bit more about the PSR of JJ, but other than this and a couple other mentions don't know of any info. The description sounds like it would be wonderful for all sorts of things. Too bad if it is nearly as good as described it wasn't a thing rather than stuff like Dolby Atmos.

 

[AJ Soundfield]

Really wish to know a bit more about the PSR of JJ, but other than this and a couple other mentions don't know of any info. The description sounds like it would be wonderful for all sorts of things. Too bad if it is nearly as good as described it wasn't a thing rather than stuff like Dolby Atmos.

Most of the info is on AES although you can google the patent as well. His ppt slides give good info to if you know what to look for, example here
Atmos is for movie gimmicks, PSR was aimed squarely at music.
That said, 99.9% of music was and is still stereo. That's the reality. There are ways to enhance the chicken salad.

cheers,

AJ

 

[h.g.]

Let's go through a simple scenario. You play two files for me which have proven audible differences. I hear that audible difference just the same. But then worry that you may be tricking me by playing the same two files and that the difference I heard may be imagined and I declare the two files the same. In other words, I heard one thing, but voted another. A measurement does not make these mistakes because there is no human in there applying judgement.

I am not a doctor so don't know the accuracy of an unskilled person performing such tests depends on some kind of judgement. If you do then you can apply the above to it and figure out if it is subjective or objective.

If it was an unskilled person working out an inaccurate heart rate it would be a subjective judgement but if a skilled person performed the same task accurately it would be an objective measurement? Does that really look right to you?

You would appear to have mixed up the meanings of measurement, measurement error, subjective and objective in a weird and wonderful way. This is possibly fine in the audiophile world where words seem to have associations rather than agreed meanings but I would suggest it is likely to put off people contributing to your forum that view sound and audio in a more conventional scientific manner.

 

[amirm]

If it was an unskilled person working out an inaccurate heart rate it would be a subjective judgement but if a skilled person performed the same task accurately it would be an objective measurement? Does that really look right to you?

Again, I can't comment about a domain I don't know about.

You would appear to have mixed up the meanings of measurement, measurement error, subjective and objective in a weird and wonderful way. This is possibly fine in the audiophile world where words seem to have associations rather than agreed meanings but I would suggest it is likely to put off people contributing to your forum that view sound and audio in a more conventional scientific manner.

???
I am using the accepted scientific/industry terms. Not what is used in forums or by audiophiles. No doubt you are familiar with my colleague Dr. Sean Olive and his extensive work in evaluation of audio products/loudspeakers using double blind methodology? Here is how he introduces himself: http://seanolive.blogspot.com/

Sean Olive is Director of Acoustic Research for Harman International, a major manufacturer of audio products for consumer, professional and automotive spaces. He directs the Corporate R&D group, and oversees the subjective evaluation of new audio products including Harman's OEM automotive audio systems.

Listening tests are always subjective. You may ask listeners to assign numbers to things but that doesn't make them measurements. Or objective analysis. When evaluating audio you are either doing it by ear or equipment. Those domains remain separate.

What I write here is part of work that I used to do professionally. Please see a synopsis of it here: http://www.audiosciencereview.com/forum/index.php?threads/introductions-anyone.65/ It is not hobby speak.

 

[h.g.]

Again, I can't comment about a domain I don't know about.

You weren't being asked to comment on a domain you don't know about (I am pleased to say I resisted the obvious jab - although I did succumb to this one) but to check the consistency of your reasoning. Perhaps more importantly you did not ask about what might be wrong given I was not telling you. You just ploughed on. Whatever, I was just checking.

 

[amirm]

You weren't being asked to comment on a domain you don't know about ...

You were asking me to comment on measuring heart rate. I don't know what about medical domain so can't comment on analogies there. I did give you may lay opinion earlier and since that did not suffice, I did not want to venture further.

(I am pleased to say I resisted the obvious jab - although I did succumb to this one) but to check the consistency of your reasoning. Perhaps more importantly you did not ask about what might be wrong given I was not telling you. You just ploughed on. Whatever, I was just checking.

I felt quite a big jab coming my way saying I was using audiophile terminology instead of accepted scientific norm. So I recited my resume just like any type A person on a forum might.

So please, explain what you think I said wrong and I am happy to address it.

 

[h.g.]

So please, explain what you think I said wrong and I am happy to address it.

From my point of view what you did wrong was fail to respond like someone with a technical interest. Getting some things wrong or a bit off when trying to get something off the ground is not a problem. The only people that don't make mistakes are those that don't do anything. What is a problem though is not being reasonably efficient at finding and fixing mistakes in the information that is considered important otherwise quality will not improve with time.

From your point of view there may be little wrong depending on your objectives and the information you consider important. I doubt there is much you can do about changing how you reason and see the world. Some people construct and evolve an internal model of how things work and some people don't.

 

[amirm]

You ask an interesting philosophical question about "open mindedness." My stance is the same as what happens in real life. If I tell my doctor that I read online that smoking oregano cures lung cancer, and he rolls his eyes and dismisses it out of hand, is he closed minded, unwilling to have his internal model of how medicine work evolved? I think we all can agree that it is not reasonable for him to be open to any and all information against his training and experience. The same doctor however will go a to medical conference or read a paper, learning something new and modify his internal model appropriately.

What is the difference? The assumed or demonstrated foundation upon which the information is presented. Me giving him medical advice based on stuff I read online and lay assumptions of how lung cancer works, is not remotely in the same league as professional with even more experience than the good doctor sharing what they have discovere.

As always, I have a personal story to share here . My doctor prescribed a new medication for me and I started to have some discomforts. In my next visit I tell him that and he says he doesn't think it is related to that medication. I go home and still suffer the symptoms. I go online and search for that drug and my symptoms and the very first hit shows that. Not only that, that hit was the study research outcome from the drug company that created it! It showe X% of subjects in the medical trials suffered from my exact symptoms! Aha, my doctor was wrong.

On my next visit I proudly tell him that I had done some research and that my symptoms matched side effects reported by others. He asked me what my source of research was. Sheepishly I say "the Internet!" But then follow by telling him it was from the drug company. In very calm voice he said that when they conduct these experiments they record any and all symptoms patients report whether related or unrelated to the drug. It is then totally natural for X% of the patients in the study to report headaches, upset stomach, dizziness, etc. He said the reliable data is what doctors have: they prescribe these medications hundreds and thousands of times and build up a practice library of what symptoms are likely and not likely. And that my symptoms are unlikely.

Would you know it? The son of a gon was right. My other symptoms went away while I was taking the medication. The above is the last time I will challenge my doctor on his specialty on what I read online .

With respect to this topic, I read and modify my understand of audio all the time. Five years ago I threw out everything and I mean everything I thought I knew on room acoustics. All of that was learned from reading forms. Turns out most if not all of it was wrong. There was an amazing body of research that backed that. The research that is rarely shared online and in forums.

The above is what motivated me to create this forum and prior to that, writing articles doing the same. Do I learn from members here just the same? Sure, it happens and I read every link and reference provided. My mind is open to learning. My mind is not open to folklore though, presented without backup. That is who I am. So if that is what you mean by unwillingness to change, guilty as charged .

 

[h.g.]

You ask an interesting philosophical question about "open mindedness."

Not really. I was establishing whether you reasoned like a scientist/engineer or not to help determine how well this forum was likely to serve my purposes.

Perhaps it is easier to see it in others rather than oneself. In another thread Ethan wants some support for his interests and would like to be able to show multiple subwoofers are not as effective as his room treatments. He knows his room treatments dissipate sound but cannot see how multiple subwoofers can do likewise and would like some pictures that they don't (or perhaps an absence of pictures). The point is that he thinks like a technician rather than an engineer and is looking for recipes rather than to tweak his internal model of how sound works in a room. A poke to get him thinking about what he knows was no more effective on him than it was on you.

(Of course additional subwoofers can add or remove sound depending on phase and indeed a few years ago K&H used to market a subwoofer with a few knobs as an "active room absorption module". The manual contains the pictures he claims to want.)