Most probably because there is no known reference in a studio recording - one cant simply not know if something is truthfully reproduced as everything gets skewed and changed by close mic:ing and signal manipulation - many time instruments have never sounded in air bit rather captured as a electrical signal.
No one has heard a studio recording and thus, cant say if it is correctly reproduced. One can only say of it sounds nice and this if a subjective personal preference. Why would Greisinger involve that?
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Hi, yeah "near field" is related to the speaker so I've been using word close to avoid mixing them up. We should listen far field of the speaker, but close enough to be within critical distance of the room.
So critical distance would be correct term, but I do not know the actual relationship of the direct sound to reflections, all I know perception shifts at certain distance to loudspeakers. Is critical distance defined with absolute dB value or ratio, or is it just how the sound is perceived?
Griesinger most often describes the process of human hearing and perception. Some of it is about studio work though, like the paper I linked to earlier.
But if its a concert hall recording or Studio produced work, our perception tools (in other words our ears/brain combination) still functions the same.
That was enough food for thought for me and sparked enough of an interest and inspiration to learn how to apply (t)his theory to stereo and its perception.
But if its a concert hall recording or Studio produced work, our perception tools (in other words our ears/brain combination) still functions the same.
That was enough food for thought for me and sparked enough of an interest and inspiration to learn how to apply (t)his theory to stereo and its perception.
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I don't think so. He's got a lot going on and it's erratically evolutionary (changing depending on topic and developing further as he learns more).
I don't think he has it all either. What I like most about his work involves low freq.s in-room for reproduced stereo.
He doesn't look that strongly into loudspeaker dispersion at higher freq.s. He does however delve a bit more into room reflections at higher freq.s - and looks at it a bit more in terms of direct vs. reflected spl (with a bit of attention paid to higher spl reflection angle relative to the listener's head). While you could say that a "toe-in" + waveguide accomplishes a similar result it also effects loudspeaker dispersion.
He is (generally) looking for: more apparent separation at lower freq.s and less apparent separation at higher freq.s along with improved phase linearity below 700 Hz and de-correlated reflections with longer time and lower intensity (particularly at lower freq.s).
It's sort of like he's saying that above 1kHz there isn't a lot new that hasn't already been researched (and that he hasn't found to be incorrect), but below 700 Hz there is plenty of area for new research. (..having read or read summaries of what's available - I'd agree with that. It's sort of like Earl with types of distortion and audibility - it's ripe for added research/exploration.)
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So the real physical sources (like musical instruments or voices) always produce correlated harmonics? What exactly it means that they are correlated in terms of phase?
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Good question, in my view that is the tone of the played instrument or voice. Its sound is of a particular set of fundamentals and harmonics. It is the source.
Yes, but the claim is that the ears and the brain can distinguish the "correct envelope" from a phase-corrupted one (and hear it as close and engaging vs indistinct and not-engaging). Which means that the correct one - the original - must have some absolute quality that makes this distinction possible. It just can't be any signal or any envelope because than it would not be possible to say which one is the "correct one" without an actual knowledge of the original.
But perhaps it just stems from the properties of the physical systems that the harmonics are (e.g.) always in-phase - that's what I don't know.
But perhaps it just stems from the properties of the physical systems that the harmonics are (e.g.) always in-phase - that's what I don't know.
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As you never heard the sound of that record in that studio, you can never judge if your reproduced sound is correct or not.
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That's why ( sorry for the intromission) only acoustical instruments playing classical music should be chosen to evaluate a recording & the system
This opens to further investigation: is the system capable of reproducing correctly those instruments playing together ?
This opens to further investigation: is the system capable of reproducing correctly those instruments playing together ?
As layman I'm not sure if it is necessary to know the details. I mean, when harmonics line up with fundamental there is amplitude peak, which sticks out from noise, from all sound with relatively smooth amplitude as average. Not sure if there is more to it, its just something brain considers being close and important when sound has relatively high D/R ratio. There are sounds that do not have much harmonics, like sine tone from a synth. And the harmonics can be ruined in the recording as well, mic too far or processed to death. On the playback side I think we should care that the speakers and the room does not significantly alter this.
I think this is irrelevant, whats on the recording is what was put in there. All we can do is playback the recording, preferably with neutral or enhanced experience so that what is on the recording delivers as intended. At least we should avoid negative experience by ruining it with something, like resonances or other problems that stick out, features on the playback system or local environment that grabs attention instead.
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The short version:
or this one, where specific attention is drawn to phase behavior above 1 Khz (often denied/neglected in stereo theory because of the inherited flaws of that system):
The longer version, not directly related to stereo, just about the hearing mechanism:
https://www.akutek.info/Papers/DG_Neural_Mechanism.pdf
It actually becomes harder to reproduce in stereo, where two sound sources mimic the sound as if it is coming from straight ahead 😉.
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Seek and find 🙂 Critical distance is defined with ratio of 1, or direct and reverberant sound being equal. Not by perception. Couldn't find how critical distance relates to perception except some hints. Griesinger talks about the perception, but does not relate it to critical distance, but to LOC, a formula that calculates neuron firings within 100ms window and compares ratio between firings of direct and reverberant sound, +3db means high chance of clarity.
Linkwitz shows example calculations for critical distance here https://www.linkwitzlab.com/rooms.htm and mentions that
"... It has the effect of making the reverberation distance xr = 1.04 m for the monopole and xr = 1.8 m for the dipole. At a viewing/listening distance of 2 m the direct sound is only about 6 dB below the reverberant level of the monopole which is good for sound clarity. "
Which to me hints that critical distance is quite short in typical living rooms in general and that clarity can happen beyond the critical distance, so that the perception does not change at critical distance but perhaps bit further away, when D/R is still sufficiently high.
Have you experimented with it, walking back and forth on the stereo triangle center normal and notice the perceptual shift? When close enough, there seems to be better clarity and sharper localization but when you step back there seems to be quite distinct change when the clarity goes away and localization is not as sharp any more. In my room and setup being on the far side of transition the sound is front of me, there is no envelopment, but when close enough its much more 3D experience, sound is not just front but enveloping. Its literally feels like stepping inside the recording, hence calling it transition.
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No amount of reflections (nor a phase distortion due to an all-pass loudspeaker response) in a room ever scrambles the signal so much that it sounds so distorted as Griesinger presents. I really have to wonder about the validity of it and its real implications here. It's like saying that broken speakers don't sound right.
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You may draw your own conclusions, keeping the phase relations in tact at the ear at the listening spot tells me something different.
Yes, if the "Nice" approach as opposed to "Correct" is accepted/wanted, my statement is irrelevant.
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It's indeed hard to accept that the phase reponse per se has much to do with it, as its linearization alone (i.e. correction of the phase distortion induced by a typical crossover) does very little, if anything, to the sound, as anyone can easily try themselves.
All 4-way speakers with steep passive filters, like Revel Salon 2, would be barely listenable it this was the case...
All 4-way speakers with steep passive filters, like Revel Salon 2, would be barely listenable it this was the case...
Yeah, to me it makes a lot of sense if you take what Griesinger writes that brain either locks in or not, phase distortion inaudible until it is 😉 If you stay within one or another you might not notice any difference. I speculate that phase is distorted already when listening too far, I think that's the definition to being too far by Griesinger, brain doesn't lock in and perceive close sound only the room sound. If this assumption is true then any phase manipulation (of loudspeaker) is not audible on the far field other than how the frequency response changes. Then, when phase is good enough the brain locks in and perhaps that's it, no further improvement. Obviously phase of both speakers should match each other, this is audible if it doesn't phantom center smears up.
As I've been saying I do not know if the perception difference at home relates to what Griesinger says but we gotta remember the hearing system is same, only environment differs at home to lecture halls. And, similar perceptual difference seems to happen at home stereo as well, on/off shift in "stereo quality", more or less clarity and all that. Although I'm not expert on hearing system I would guess the hearing infrastructure is as simple as possible and think it is very likely it's the same mechanism working detecting important close sounds be in small or large room.
It would be very convenient if it is exactly the same thing at home what Griesinger writes: listening close enough brain is able to separate foreground and background sounds to different neural streams. While listening too far it doesn't happen and there is only one neural stream, wash of room sound, brain does not consider direct sound to be important and doesn't pick it up. This would mean the engagement and all that happens only on the close listening, which to me feels true. Certainly sound is much more compelling listened close enough than at the far distance.
Well, my impressions are just mine and it doesn't matter too much if its not the same as Griesinger writes. I now know what I want to hear, I want the close sound over the far one, and have possibility to play around with the subject. I think it is very important for everyone to hear the transition, what the close sound sounds like and what the far sound sounds like. Gives a lot of perspective and something to reason with. Certainly it seems to be matter of enough direct sound over room sound as simplest.
I suggest trying to find the critical distance at home with listening. Difference is stark enough that I consider only the close distance being hifi while the far is very good it's not the same. It's worth it to know which sound you like, and where the transition is, in order to reason with your system and room and their relationship. If nothing else it should give perspective on how your room sounds because it largely switches off while close enough, or at least some quality of room seems to disappear.
As I've been saying I do not know if the perception difference at home relates to what Griesinger says but we gotta remember the hearing system is same, only environment differs at home to lecture halls. And, similar perceptual difference seems to happen at home stereo as well, on/off shift in "stereo quality", more or less clarity and all that. Although I'm not expert on hearing system I would guess the hearing infrastructure is as simple as possible and think it is very likely it's the same mechanism working detecting important close sounds be in small or large room.
It would be very convenient if it is exactly the same thing at home what Griesinger writes: listening close enough brain is able to separate foreground and background sounds to different neural streams. While listening too far it doesn't happen and there is only one neural stream, wash of room sound, brain does not consider direct sound to be important and doesn't pick it up. This would mean the engagement and all that happens only on the close listening, which to me feels true. Certainly sound is much more compelling listened close enough than at the far distance.
Well, my impressions are just mine and it doesn't matter too much if its not the same as Griesinger writes. I now know what I want to hear, I want the close sound over the far one, and have possibility to play around with the subject. I think it is very important for everyone to hear the transition, what the close sound sounds like and what the far sound sounds like. Gives a lot of perspective and something to reason with. Certainly it seems to be matter of enough direct sound over room sound as simplest.
I suggest trying to find the critical distance at home with listening. Difference is stark enough that I consider only the close distance being hifi while the far is very good it's not the same. It's worth it to know which sound you like, and where the transition is, in order to reason with your system and room and their relationship. If nothing else it should give perspective on how your room sounds because it largely switches off while close enough, or at least some quality of room seems to disappear.
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