The ASR "objectivists tribe" ;) has to read the Keynotes at the AES160th by Lars Risbo

[olieb]

While I agree (linear) bass performance is extremely important, I sometimes feel like the "bass is 30% of perceived sound quality" is expressed as somehow 30% is more than 70%.

Agreed.
If we take the audible range as 20Hz to 20kHz that is 3.0 decades.
Bass (linearity/flatness AND extension) is more or less 20-200Hz or 1.0 decade, 33% of the audible range.
[Actually bass range is up to 300Hz in Olives's model.
“LFQ is intended to quantify deviations in amplitude response over the bass region between the low frequency cut-off and 300 Hz.“ (A Multiple Regression Model for Predicting Loudspeaker Preference Using Objective Measurements: Part II Development of the Model)]
So 30% “importance“ of bass (linearity/flatness AND extension) means that bass has about average importance/range.
Assuming that the top decade (2-20kHz) has 20% to 30% importance, that leaves 40% to 50% for mids (200Hz-2000Hz).

 

[IPunchCholla]

Agreed.
If we take the audible range as 20Hz to 20kHz that is 3.0 decades.
Bass (linearity/flatness AND extension) is more or less 20-200Hz or 1.0 decade, 33% of the audible range.
So 30% “importance“ of bass means that bass has about average importance/range.
Assuming that the top decade (2-20kHz) has 20% to 30% importance, that leaves 40% to 50% for mids (200Hz-2000Hz).

Not to disagree with your reasoning, but I always took the bass is 30% of perceived sound quality to include more than just the audible frequency range which would make that 30% weighting far more significant. But now I can’t remember why.

 

[Shindo_Joe]

Ok after reading the whole thread I gotta say something.

This thread is itself the cleanest example of what Lars Risbo's keynote was about. Call them tribes, camps, colleagues, POVs, whatever you want. The pattern is the same on both sides. One camp says the measurements settle it. The other says the measurements are missing something. And neither is really asking new questions anymore.
We just spent 25 pages re-litigating Toole, the McGill pilot, sidewalls, hysteresis, etc. and almost nobody is actually engaging with what Lars concluded, which was NOT "buy Purifi" and NOT "subjectivists were right all along". It was this:

"What bothers me about both tribes is not that they disagree. It's that neither is curious. Both have found a way to stop the inquiry and call it a conclusion."

Thats the whole thing, compressed. Knowledge in audio, like in ANY engineering field, is an evolving thing. Measurements get better, mechanisms we couldnt capture become capturable, caveats the original researchers put in their own papers get quietly dropped downstream. The right posture isnt to defend last decade's answer, its also not to dismiss it. Its to keep asking what the current metric set might be missing.

And honestly, kudos to Lars Risbo, he modeled exactly that posture inside this very thread. At #209 he tightened a claim under pressure from @amirm. At #217 he conceded a wording error to KSTR. At #317 he thanked a critic for "exactly the kind of discussion I was hoping for." Thats it. Thats the engineering attitude in action. The guy literally did the thing he was preaching, on this forum, in front of all of us, and most of the responses since have been about whether he attacked Toole or not.

He didnt attack Toole. He pointed out caveats Toole himself wrote into the original work and asked what happened to them. There's a difference.

@Lars Risbo your thesis still stands imo. Stay curious isnt a slogan, it's the whole point. IMHO anyway.

 

[sqrl]

Also people overinterpret lack of studies. It happens in medicine; there is no evidence that this works just means there is no evidence it doesn't mean it doesn't work it just means there are not enough studies.

This is misleading. If there is no theoretical mechanism by which a medical treatment could possibly work, or no basic, preclinical evidence of a relevant effect in a biological system, doing clinical studies would be practically and ethically dubious.

For a potential treatment, if there are clinical studies with "no evidence that this works" in a defined group of participants, you can calculate the effect size and determine if the studies just lacked the statistical power to show it works.

 

[Buckeye Amps]

This is misleading. If there is no theoretical mechanism by which a medical treatment could possibly work, or no basic, preclinical evidence of a relevant effect in a biological system, doing clinical studies would be practically and ethically dubious.

For a potential treatment, if there are clinical studies with "no evidence that this works" in a defined group of participants, you can calculate the effect size and determine if the studies just lacked the statistical power to show it works.

^this x100

 

[MattHooper]

This is misleading. If there is no theoretical mechanism by which a medical treatment could possibly work, or no basic, preclinical evidence of a relevant effect in a biological system, doing clinical studies would be practically and ethically dubious.

For a potential treatment, if there are clinical studies with "no evidence that this works" in a defined group of participants, you can calculate the effect size and determine if the studies just lacked the statistical power to show it works.

Indeedy.

I guess I’m surprised that I’m surprised about some of the statements made on a forum with “science” in the title.

 

[Sal1950]

Many people here don't even have a pair of loudspeakers optimally placed in the room, let alone in a treated listening room where the impact of side reflections could be properly evaluated

I really hope that's not true for our base membership, why would anyone join a Hi-Fi dedicated site like this if that's their attitude?

Bob: Hey Larry, don't eat raw pork, it's dangerous!

OH MY, that's what my mother used to scream at me when she would catch me eating the raw bacon in the fridge. 76 years later I'm still here. LOL

To expand on my earlier point, while many enjoy music despite not having a dedicated room, can also say that none of my kids (2 live in apartments) even have a hifi system despite experiencing superior sound in my home.

The old saw of " you can lead a horse to water but you can't make em drink" is so true there.
Little by little this passion is dying with little hope of recovery. I think some of the reason may be related to the fact that the last generation or 2 have grown up with reasonably good sounding music all around them. My ole boomer generation grew up with mostly horrid sources like 6 transistor AM radios, 45rpm records and blaring jukeboxes. That put a yearning in many of our guts for something better that continued all thru life.

I guess I’m surprised that I’m surprised about some of the statements made on a forum with “science” in the title.

I'm mostly surprised that it's generally agreed here that the two most important things in home Hi Fi reproduction are the speakers and the room. Now some want to throw the room and it's treatment out of the equation ?

 

[PristineSound]

Ok after reading the whole thread I gotta say something.

This thread is itself the cleanest example of what Lars Risbo's keynote was about. Call them tribes, camps, colleagues, POVs, whatever you want. The pattern is the same on both sides. One camp says the measurements settle it. The other says the measurements are missing something. And neither is really asking new questions anymore.
We just spent 25 pages re-litigating Toole, the McGill pilot, sidewalls, hysteresis, etc. and almost nobody is actually engaging with what Lars concluded, which was NOT "buy Purifi" and NOT "subjectivists were right all along". It was this:

Thats the whole thing, compressed. Knowledge in audio, like in ANY engineering field, is an evolving thing. Measurements get better, mechanisms we couldnt capture become capturable, caveats the original researchers put in their own papers get quietly dropped downstream. The right posture isnt to defend last decade's answer, its also not to dismiss it. Its to keep asking what the current metric set might be missing.

And honestly, kudos to Lars Risbo, he modeled exactly that posture inside this very thread. At #209 he tightened a claim under pressure from @amirm. At #217 he conceded a wording error to KSTR. At #317 he thanked a critic for "exactly the kind of discussion I was hoping for." Thats it. Thats the engineering attitude in action. The guy literally did the thing he was preaching, on this forum, in front of all of us, and most of the responses since have been about whether he attacked Toole or not.

He didnt attack Toole. He pointed out caveats Toole himself wrote into the original work and asked what happened to them. There's a difference.

@Lars Risbo your thesis still stands imo. Stay curious isnt a slogan, it's the whole point. IMHO anyway.

That's fine to make that statement of being curious, but being curious still requires scientific evidence.

Whether there is new or evolving science in the audibility of HiFi audio or not, whether we know how to measure it or not, whether legit or not, we already have this one super powerful and authoritative tool, it's called ABX, preferably double blind.

Tell me what exactly is it that you think may be audible or not, and let's create a ABX. I know such ABX isn't always easy to set up and cheap, but if you think something is audible and worth mentioning, then pursuing said test is also worthy.

 

[amirm]

Now some want to throw the room and it's treatment out of the equation ?

What is the solution to that equation?

 

[Vuki]

That's fine to make that statement of being curious, but being curious still requires scientific evidence.

Whether there is new or evolving science in the audibility of HiFi audio or not, whether we know how to measure it or not, whether legit or not, we already have this one super powerful and authoritative tool, it's called ABX, preferably double blind.

Tell me what exactly is it that you think may be audible or not, and let's create a ABX. I know such ABX isn't always easy to set up and cheap, but if you think something is audible and worth mentioning, then pursuing said test is also worthy.

You are aware that it could be quite a challenge to ABX test two rooms? Even two loudspeakers (Harman got close) is very complicated. But two pairs of loudspeakers is almost impossible (don't know anyone did it).

 

[amirm]

You are aware that it could be quite a challenge to ABX test two rooms?

Not really. The McGill study did just that. And it is not ABX that we are after but preference. If the differences are so small as to need ABX, then it is not material.

FYI RPG used to have a product called Trifuser. It kind of looked like this:

You could rotate them and very quickly change from absorption to reflection to diffuser. It wasn't so good at diffusion but it allowed this kind of quick testing. We had a room at Microsoft where all the walls were this way.

 

[PristineSound]

You are aware that it could be quite a challenge to ABX test two rooms? Even two loudspeakers (Harman got close) is very complicated. But two pairs of loudspeakers is almost impossible (don't know anyone did it).

ABX two rooms is very difficult, ABX two speakers is difficult for you and me, because we don't have the tools. Where are you getting that Harman wasn't able to do it? This is done and it's widely discussed by Toole.

 

[amirm]

But two pairs of loudspeakers is almost impossible (don't know anyone did it).

Not only did Harman do that for 2 speakers, they did it for 5! It was their MLL room:

It is covered in this paper:
A New Laboratory for Evaluating
Multichannel Audio Components and Systems
SEAN E. OLIVE, AES Fellow, BRIAN CASTRO, AES Member, AND
FLOYD E. TOOLE, AES Fellow

 

[Vuki]

Not really. The McGill study did just that. And it is not ABX that we are after but preference. If the differences are so small as to need ABX, then it is not material.

FYI RPG used to have a product called Trifuser. It kind of looked like this:

You could rotate them and very quickly change from absorption to reflection to diffuser. It wasn't so good at diffusion but it allowed this kind of quick testing. We had a room at Microsoft where all the walls were this way.

You know this is not a room, but acoustic treatment? Rooms can have different proportions, be built with different materials etc., but you know that...

 

[Mort]

I think you missed the point about the difference between an ABX and a preference test.

 

[Vuki]

ABX two rooms is very difficult, ABX two speakers is difficult for you and me, because we don't have the tools. Where are you getting that Harman wasn't able to do it? This is done and it's widely discussed by Toole.

Not all loudspeakers perform optimal at the same position - shuffler puts every tested loudspeaker at the same position.

 

[PristineSound]

Not all loudspeakers perform optimal at the same position - shuffler puts every tested loudspeaker at the same position.

And that exactly what an ABX is.

 

[Vuki]

And that exactly what an ABX is.

What is?

 

[Audio Science Pal]

Not really. The McGill study did just that. And it is not ABX that we are after but preference. If the differences are so small as to need ABX, then it is not material.

FYI RPG used to have a product called Trifuser. It kind of looked like this:

You could rotate them and very quickly change from absorption to reflection to diffuser. It wasn't so good at diffusion but it allowed this kind of quick testing. We had a room at Microsoft where all the walls were this way.

Those are interesting. Was that room at Microsoft ever used for music listening?

 

[NTK]

You are aware that it could be quite a challenge to ABX test two rooms? Even two loudspeakers (Harman got close) is very complicated. But two pairs of loudspeakers is almost impossible (don't know anyone did it).

I've already mentioned it in post #157 of this thread. The technique developed to overcome this problem is called Binaural Room Scanning. It was described in this paper by Philip Mackensen et al.

https://pubs.aip.org/asa/jasa/article/105/2_Supplement/1343/549212/Binaural-room-scanning-A-new-tool-for-acoustic-and

Dr Olive coauthored this paper with and his PhD thesis advisor Dr Martens and Todd Welti on their application and evaluation of this technique.

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