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Importance of impulse response

fineMen

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... a complex set of compromises that don't lend themselves to simple yes or no answers.
Nope, there is no problem, that simple, and done. The audiophile is always looking out for problems in order to *not* enjoy the music. Sounds weired, but so it is. Just so.

... excess group delay. This is cumulative and builds up from every crossover in the system. Like the example kimmosto showed above the lowest and steepest crossovers (IIR/analogue) cause the most harm.
No, there is no difference analog versus digital, and IIR can be as good as it gets.

There is then the impact of the room, whether the speaker has a perfect step response or dreadful step response it will still be affected by room interaction. ... Rooms introduce non minimum phase artefacts and the cumulative effect of these can create an extra layer of excess group delay. While it isn't advisable to try and equalise most of this you can with careful processing bring the response at the listening position back towards minimum phase. I find that overall this has a positive impact on sound quality but is source dependant and can sometimes make things sound less energetic.
Subjective, sighted preference is not a predicator for anything. Most probably it is pure imagination--we had that so many times with so many mysteries. It was never proven that people in an ordinary situation could detect or even 'prefer' a certain group delay or just none.

Making a speaker time coherent above 600Hz is going to be subtle in most cases (of reasonably well engineered speakers to begin with). With casual listening and studio recordings picking the difference would be hard for most. But with time and naturally recorded source material of real instruments in real spaces some difference can be heard tending towards making things sound more realistic and true to life.
And reiterated the common saying from the 'golden ears': "picking the difference would be hard for most". Should I now feel a deficit with my hearing? Me suffering because I can't enjoy the delicacy of my stereo, or can't fairly worship the stereo of somebody else? To the contrary, I'm happy to just dismiss the idea of that violent imperfection in 'time response'. I'm glad with the the music given to me.

Real instruments in a stereo recording? I know a few musicians who are in the recording business. They actually do not like the sound of recorded instruments to put it mildly. A recording is something else in its own right, not a replica of the real sound. To talk about "the real" is a typical, if not the original audiophile's fairy tale; only the naive, not familiar with the real thing can believe it.

Below 400Hz the difference is much more obvious and can be a combination of effects from the speaker itself and the room.

Rod Elliot has quite a good article that describes the mechanics of some of these things
https://sound-au.com/ptd.htm

You actually must not equalize the room's group delay in bass and lower mids. The hearing needs it!

The latter link is well chosen. But to make the point even more clear, read that chapter first: https://sound-au.com/ptd.htm#s4 You may feel that it isn't necessary to dig further. Dr Toole is a highly respected scientist with speakers being his dedicated working field. One cannot have an opinion on science. If you distrust it, prove it!
 
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kimmosto

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Dr Toole is a highly respected scientist with speakers being his dedicated working field. One cannot have an opinion on science. If you distrust it, prove it!
As far as I know, Dr. Toole has not published any papers about audibility or perceptibility of normal or excess group delay between response extends. He has just referred carefully selected parts of studies and conclusions by others. Probably this old one too: "On the Audibility of Midrange Phase Distortion in Audio Systems" by Lipshitz, Pocock and Vanderkooy. Also that paper can be turned into black, gray or white depending on whatever personal motivation because states both "phase distortions can unquestionably be audible" and "all the effects described can reasonably be classified as subtle". So please don't grow your dogmas any bigger and try to seed them here. At least I don't care a sh*t about your personal priorities, abilities and opinions/interpretations what science knows and what it doesn't.
 

fineMen

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As far as I know, Dr. Toole has not published any papers about audibility or perceptibility of normal or excess group delay between response extends.
I didn't say that. Isn't it already enough with this as ever misleading 'golden ear' topic? I would say Gentlemen! Yes, indeed.

As not to mention that I proved that many here don't know what the own talking is about ...
 

kimmosto

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Isn't it already enough with this as ever misleading 'golden ear' topic?
Nowadays FIR DSP gear is as expensive or inexpensive as IIR gear so why you attack against golden ears or manufacturers trying to eliminate one more obvious and perceivable error in sound reproduction without increasing costs or profit? Your arguments are simply stupid and unconstructive, and I would ignore you as a troll with forum features if that would be possible.
 

Jim Taylor

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I would ignore you as a troll with forum features if that would be possible.

It's possible. Left-click on an avatar, and the option will show on the inset screen.

Jim
 

fineMen

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Nowadays FIR DSP gear is as expensive or inexpensive as IIR gear so why you attack against golden ears or manufacturers trying to eliminate one more obvious and perceivable error in sound reproduction without increasing costs or profit? Your arguments are simply stupid and unconstructive, and I would ignore you as a troll with forum features if that would be possibl
Please read this article (https://sound-au.com/ptd.htm#s4 ) to learn that your musings are directed against science without any motivation other than a subjective imagination. To blow it up as "one more obvious and perceivable error in sound reproduction" doesn't make an argument. To then ask science to prove you wrong appears to me a bit entiteled.

I've seen these lines of argument too often. But I won't save the world. CU

One may ask why I'm after this at all. It is because the proponents of the myth in discussion gave me three real scientific papers to read that should prove their point. Only later it came out, they didn't read them themselves. Other that read them afterwards didn't understand the text, only quoting some singled out formulations. The original text was about hearing aids. Means, people who need help. Not anyway dissatisfied 'golden ears', but the opposite. Go figure! (Needless to say that the papers came to a contradicting conclusion, just the opposite of what people wanted me to find there ... )
 
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dualazmak

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Although quite belated, let me briefly join here sharing my rather naive but fundamental measurements and tuning of SPs.

At least for me, "impulse response" wound be identical to "transient characteristics" of each of the SP drivers and "transient characteristics" of total SP consists of several SP drivers.

I shared my measurements of "transient characteristics" of sub-woofer, woofer, and midrange by tone burst signals; my special interests were/are "transient characteristics" of two SP drivers around the cross-over Fq; it should be really critical for subjective listening experiences in terms of sound tightness/sharpness/compactness.
- Measurement of transient characteristics of Yamaha 30 cm woofer JA-3058 in sealed cabinet and Yamaha active sub-woofer YST-SW1000: #495, #497, #503, #507
- Precision measurement and adjustment of time alignment for speaker (SP) units: Part-3_ Precision single sine wave matching method in 0.1 msec accuracy: #504, #507

Furthermore, I measured and do believe the total system "transient characteristics" would be greatly depending also on time alignments between the SP drivers as well as between L-SPs and R-SPs, as summarized in my post here.
The details of my "time alignment" measurements and tuning can be found;
- Precision measurement and adjustment of time alignment for speaker (SP) units: Part-1_ Precision pulse wave matching method: #493
- Precision measurement and adjustment of time alignment for speaker (SP) units: Part-2_ Energy peak matching method: #494
- Precision measurement and adjustment of time alignment for speaker (SP) units: Part-3_ Precision single sine wave matching method in 0.1 msec accuracy: #504, #507
 
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fluid

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Nope, there is no problem, that simple, and done. The audiophile is always looking out for problems in order to *not* enjoy the music. Sounds weired, but so it is. Just so.
I don't consider myself an audiophile and my aim is to understand what makes a speaker sound good or bad and more or less accurate. Enjoyment is a personal thing and if simple and straightforward gets you there, fantastic. I enjoy the challenge of understanding audio and experimenting with it just as much as I do listening to music, I don't consider them mutually exclusive.
No, there is no difference analog versus digital, and IIR can be as good as it gets.
In case it wasn't clear to you the point was about filter topologies that cause significant group delay that exceeds any established level of audibility.
Like in this chart from one of the previously linked papers, Audibility of group delay equalization.

GD Audibility Graph.PNG


Group delay can be compensated with analogue filters too it is just much less common.
https://audioxpress.com/article/frequency-delay-dispersion
Subjective, sighted preference is not a predicator for anything. Most probably it is pure imagination--we had that so many times with so many mysteries. It was never proven that people in an ordinary situation could detect or even 'prefer' a certain group delay or just none.
It is a good predictor of your own enjoyment. Whether that is through real technical improvement or imagination the result for the individual is the same.
This is something that is easy for anyone to test for themselves with an ABX comparison. There is no need to accept my personal finding.
And reiterated the common saying from the 'golden ears': "picking the difference would be hard for most". Should I now feel a deficit with my hearing? Me suffering because I can't enjoy the delicacy of my stereo, or can't fairly worship the stereo of somebody else? To the contrary, I'm happy to just dismiss the idea of that violent imperfection in 'time response'. I'm glad with the the music given to me.
This has nothing to do with "Golden ears", your hearing capability or enjoyment. Some signals and aspects of musical instruments are more revealing of certain flaws than others, e.g. Olive and Toole's Resonance audibility study. Listener training is something that can assist in helping anyone to identify and describe certain flaws that may otherwise have gone unnoticed. You may not want to train yourself to be able to hear these things as once heard it is hard to ignore them and that can reduce your enjoyment.
Real instruments in a stereo recording? I know a few musicians who are in the recording business. They actually do not like the sound of recorded instruments to put it mildly. A recording is something else in its own right, not a replica of the real sound. To talk about "the real" is a typical, if not the original audiophile's fairy tale; only the naive, not familiar with the real thing can believe it.
Whether these friends like something or not is another abstraction of the point. A musician performing can never hear something in the same way as an audience member, it is no surprise that recordings don't sound the same to them.

There are those who go to great lengths to make recordings with the aim of making them sound like the real performance, John Atkinson of Stereophile is one such person I can think of as well as Tom Danley who has made a number of recordings of real sounds that he uses as test signals. Naivety is not something I associate with them.
You actually must not equalize the room's group delay in bass and lower mids. The hearing needs it!
A statement of yours that I do not share. You ask for proof and references from others but do not hold yourself to the same standard.
There is a multitude of different ways to approach corrections to room interference, some that work and some that don't. Something that I have spent a lot of my own time testing and it is much easier to wreck the sound than it is to improve it.
The latter link is well chosen. But to make the point even more clear, read that chapter first: https://sound-au.com/ptd.htm#s4 You may feel that it isn't necessary to dig further. Dr Toole is a highly respected scientist with speakers being his dedicated working field. One cannot have an opinion on science. If you distrust it, prove it!
Indeed he is and in general I don't have anything to disagree with in what he said, but the quote there does not cover all time related problems speakers and rooms can present. The things I find myself to be more audible do not fall within the parameters he set or explored there.
 

fineMen

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Please read reference 4. That indicates quite clearly that at least some investigators were not able to forecast what speaker industry can and will produce in 21st century.
I actually hoped you would eventually ignore me. Your case is lost. I quote you: " ... not able to forecast what speaker industry can and will produce in 21st century." Any relevance? Relevance is in hearing aids for demanding people. So that they can participate in social life. The opposite of what the audiophile craves for. Yes, the undertone in this writing is intended.

What you do here willingly is to irritate people, tricking them into your belief-system, namely to not trust the outcome of a stereo-playback. For whatever fictional reason.

The single only reason to talk about 'impulse', 'phase', 'group delay' is in you saying that it is relevant for you--because you can 'hear it' and it wasn't 'right'. That subjective, explicit and malicious non-enjoyment of the presumably costly stereo of yours is your business. Maybe you actually don't like music that much?

The case of group delay, phase, time etc is settled for decades. By science. For hearing aids and otherwise utterly irrelevant stereo speakers likewise.

Please listen: the playback of a recording cannot replicate the experience of a real performance, not even in the sound alone. Everyone who would relate the playback of a recording to the real performance is either talking about the excellent recording artwork, or is lying about stereo technology.
 

fineMen

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I actually hoped you would eventually ignore me. Your case is lost. I quote you: " ... not able to forecast what speaker industry can and will produce in 21st century." Any relevance? Relevance is in hearing aids for demanding people. So that they can participate in social life. The opposite of what the audiophile craves for. Yes, the undertone in this writing is intended.

What you do here willingly is to irritate people, tricking them into your belief-system, namely to not trust the outcome of a stereo-playback. For whatever fictional reason.

The single only reason to talk about 'impulse', 'phase', 'group delay' is in you saying that it is relevant for you--because you can 'hear it' and it wasn't 'right'. That subjective, explicit and malicious non-enjoyment of the presumably costly stereo of yours is your business. Maybe you actually don't like music that much?

The case of group delay, phase, time etc is settled for decades. By science. For hearing aids and otherwise utterly irrelevant stereo speakers likewise.

Please listen: the playback of a recording cannot replicate the experience of a real performance, not even in the sound alone. Everyone who would relate the playback of a recording to the real performance is either talking about the excellent recording artwork, or is lying about stereo technology.
Add: the pink elephant in the room, intermodulation distortion up to 30% with speakers that are of (a) high esteem, (b) high cost--30%! 30% get ignored because it isn't easily conveyed in fancy graphs. See, again: https://sound-au.com/ptd.htm#s3
Talking about the industry, it is sickening. But the audiophile gets what he (!) deserves, most demanding perfect impulses.
 

kimmosto

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I actually hoped you would eventually ignore me.
Hahaa, then I'm very happy to quote Audibility of Loudspeaker Group-Delay Characteristics by Liski, Mäkivirta and Välimäki once again. I can continue as long as you. It's nice that we both can select any study which supports own experience and beliefs. This one is my favorite because it supports my experience within last two decades. Only difference is that I have used also sense of hearing mechanism used by deaf people. Using whole body appears to be more valid than plain ears because pressure loss of transients is more severe problem with actual music than tiny changes in timbre. Room acoustics can be quite dry, speakers very directive down to LF or listening distance short (near field monitoring) with loudspeakers so I don't give much...any weight to investigators' statements that GD distortion is more audible with headphones. Could be at mid...high, but that does not change my experience, priorities and targets for new designs.

1670221699122.png

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Your turn to repeat your dogma...
 

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thewas

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kongwee

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As it is shown in that link just the angle can be changed, not the distance.
Pretty sure, you can sit closer to the speaker at extreme curve. It is the distance. You can see the tweeter is the furthest away from the woofers array. Tweeter is pointing down more too and backside is lifted. Everything change to get phase alignment.
 
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thewas

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Pretty sure, you can sit closer to the speaker at extreme curve. It is the distance. You can see the tweeter is the furthest away from the woofers array. Tweeter is pointing down more too and backside is lifted. Everything change to get phase alignment.
As said you don't change significantly the phase alignment (as for this the drivers would need to be moved horizontally like for example on Wilsons) but mainly the position of "focus" where the lobes add better. Anyway for really perfect phase alignment an active FIR crossover is needed, also unless the design is concentric you will only have perfect alignment just at one point but the off-axis reflected sound won't be.
 

kongwee

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As said you don't change significantly the phase alignment (as for this the drivers would need to be moved horizontally like for example on Wilsons) but mainly the position of "focus" where the lobes add better. Anyway for really perfect phase alignment an active FIR crossover is needed, also unless the design is concentric you will only have perfect alignment just at one point but the off-axis reflected sound won't be.
You just need to see the tweeter as center channel and woofers as left/right. The closer the curve, R/L are closer to you. Of course the diameter distance still remain the same across these three parts. I was talking in perspective toward sweetspot. Wilson Audio also the same.
 

thewas

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You just need to see the tweeter as center channel and woofers as left/right. The closer the curve, R/L are closer to you. Of course the diameter distance still remain the same across these three parts. I was talking in perspective toward sweetspot. Wilson Audio also the same.
Yes, but as said this distance change is very small and cannot really make passive multiway loudspeakers perfectly time aligned.
 

kongwee

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Yes, but as said this distance change is very small and cannot really make passive multiway loudspeakers perfectly time aligned.
You need the changes to be phase alignment. It is not whether it is big or small.
 

thewas

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You need the changes to be phase alignment. It is not whether it is big or small.
If the variation range is not enough which is usually the case with passive multiway loudspeakers than this is rather highend pseudocorrection, as said for a real alignment you need complex allpass or FIR filters. Also by moving the units as much as it would be necessary you introduce diffraction problems in the vertical radiation, see for example:

20191202172232_Photo1-Technics-SB-7000aWeb.jpg

Source and more: https://audioxpress.com/article/zero-phase-in-studio-monitors
 
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