Elias said:Hello Graaf,
It's nice to note someone is still on the original subject!
well at least I am trying
I believe that only better understanding of how our spatial hearing localizes PHANTOM sound sources in reverberant space - what spatial cues override others so that our hearing relies on them - can lead to optimization of stereo setup - of loudspeakers and of speaker-room interface (placement of speakers within a room and room adaptation)
for me it looks like most important for PHANTOM sound source localization (in case of intensity stereo - Blumlein, coincident, panpotted, near coincident) are ILD cues in the high frequencies
on the other hand there are strong potentially conflicting cues for localization of the loudspeakers as REAL sound sources - onset ITD and spectral cues (HRTF)
optimal stereo setup seems to be the one that maximizes ILD cues for localization of PHANTOM sources and minimizes potentially conflicting spatial cues for localization of the loudspeakers as REAL sound sources
what do You think?
best regards!
graaf
Hello,
In real life reverberation does not come from the front only.
The best a 2 speaker stereo setup can do is to remove the front wall of your room and connect it to the recording space through that opening. But you are still stuck inside your room and to it's acoustics.
UNLESS you do some additions to your system and provide the missing reverberation by other means. Ambiophonics of course is the ultimate, but most of the effect can be gained with much lesser effort.
You need envelopment to remove your room.
- Elias
markus76 said:
In real life reverberation does not come from the front only.
The best a 2 speaker stereo setup can do is to remove the front wall of your room and connect it to the recording space through that opening. But you are still stuck inside your room and to it's acoustics.
UNLESS you do some additions to your system and provide the missing reverberation by other means. Ambiophonics of course is the ultimate, but most of the effect can be gained with much lesser effort.
You need envelopment to remove your room.
- Elias
Hello,
Actually elevation in 2 speaker stereo IS possible, and it is not neccessarely a system error. It can be done either by modifying high freq spectral content of the material, or by introducing contradicting cues. In either case perceived elevation is a conclusion made by the poor confused brain.
By the way, I think you have a misconception of space. A plane is a 2D defined in a mathematical sense (like X-Y). Only a space can be 3D (X-Y-Z).
- Elias
markus76 said:
Actually elevation in 2 speaker stereo IS possible, and it is not neccessarely a system error. It can be done either by modifying high freq spectral content of the material, or by introducing contradicting cues. In either case perceived elevation is a conclusion made by the poor confused brain.
By the way, I think you have a misconception of space. A plane is a 2D defined in a mathematical sense (like X-Y). Only a space can be 3D (X-Y-Z).
- Elias
Hello,
Do you go to concert a lot?
Have you ever experienced a situation when in a non amplified indoor concert you cannot pinpoint the individual performers? This ability obviously depends on various issues.
When going to concert which one you enjoy more, being able to localise individual performer positions or hear the sound atmosphere?
- Elias
salas said:
Do you go to concert a lot?
Have you ever experienced a situation when in a non amplified indoor concert you cannot pinpoint the individual performers? This ability obviously depends on various issues.
When going to concert which one you enjoy more, being able to localise individual performer positions or hear the sound atmosphere?
- Elias
Hello,
Remember earlier I asked you if Summas provide 'they are here' or 'you are there' of an illusion, and you responded 'it is totally irrelevant' or something like that. But you see, now we come to the same position by a different route.
With 'small groups' usually 'they are here' can be achieved quite easily. This is the reason why 2 speaker stereo system demonstrations at any hifi show use these kind of records.
'You are there' is much harder to achieve and usually this is where stereo fails. To achieve this you need to remove the room. Envelopment is needed here.
The simulation I showed is valid in a given modelled room when the source can be considered a monopole, a cardioid or a dipole. Frequency dependent reflection means reflection coefficient is changing with frequency, and if you want to isolate that out of the results then it only changes the down going slope of the impulse response (of course the directivity of the source must be added to that).
I would say the simulations are pretty much valid below 1kHz or so, and that is the freq range I'm interested to show the effect I was showing.
- Elias
gedlee said:
Remember earlier I asked you if Summas provide 'they are here' or 'you are there' of an illusion, and you responded 'it is totally irrelevant' or something like that. But you see, now we come to the same position by a different route.
With 'small groups' usually 'they are here' can be achieved quite easily. This is the reason why 2 speaker stereo system demonstrations at any hifi show use these kind of records.
'You are there' is much harder to achieve and usually this is where stereo fails. To achieve this you need to remove the room. Envelopment is needed here.
The simulation I showed is valid in a given modelled room when the source can be considered a monopole, a cardioid or a dipole. Frequency dependent reflection means reflection coefficient is changing with frequency, and if you want to isolate that out of the results then it only changes the down going slope of the impulse response (of course the directivity of the source must be added to that).
I would say the simulations are pretty much valid below 1kHz or so, and that is the freq range I'm interested to show the effect I was showing.
- Elias
Hello,
Yes. Ambiophonics does all that for localisation (of course it does other things as well).
When you remove cross talk and place speakers in +-5 degrees, for typical recordings you have ILD cues left. And for the frontal real sources to be perceived, there are not much conflicting cues either.
Then the question is: How to achieve what Ambiophonics does by other (=easier) means? (A brave assumption is however, that it _might_ be possible, but of course it also _may not_ be)
- Elias
graaf said:
Yes. Ambiophonics does all that for localisation (of course it does other things as well).
When you remove cross talk and place speakers in +-5 degrees, for typical recordings you have ILD cues left. And for the frontal real sources to be perceived, there are not much conflicting cues either.
Then the question is: How to achieve what Ambiophonics does by other (=easier) means? (A brave assumption is however, that it _might_ be possible, but of course it also _may not_ be)
- Elias
Elias said:
I think that you are picking situation that emphasize your position and ignoring the others.
"They are here" or "you are there" are different impressions and I did say that I lean towards "they are hear". I totally disagree that "'they are here" can be achieved "quite easily", at least not without coloration and image problems. To me, the "you are there" is easier to achieve because imaging, as you say, is not a dominant aspect of this, its mostly "spatiousness and envelopment" which can EASILY be achieved with wide directivity and live rooms. With no imaging capability, of course.
If you read the reviews of my speakers you will see that the listeners found that they did all of this quite well. Envelopment and spaciousness is achieved with a very live room and imaging with low diffraction high directivty, constant directivity. It is certainly possible to take things to either extreme by completely forfeiting the other - you can optimize arround "they are here" or around "you are there", but the trick is to get "good" results from both. You are obviuosly going to the "you are there" extreme to the forfeit of all else. Since only a very small fraction of music sold today is of this nature that is a very unique position to take. Far more common here than elsewhere, I will admit.
Elias said:
As I wrote, when in tens of meters distance indoors, there is only a sense of grouping in my experience (been a lot) and no pinpoint. This distance about doubles in open space concerts.
I enjoy the breathe and velvety sweep of the orchestra as a whole. I always feel that it comes from the front in a 16:9 frame, and it dies smoothly by the sides. In crescendos the space booms and then it surrounds.
Elias said:
it sounds convincing and I understand why You stress the importance if higher directivity in the low frequencies
on the other hand perhaps stereo can work also in different way - a way typical in most situations that is when low frequency reflections invalidate "ongoing ITD" spatial cues by making them ambiguous and when our hearing relies on the only reliable spatial cue defining a PHANTOM sound source that is left (in case of intensity stereo) - I mean high frequency ILD
what do You think?
best regards!
graaf
Elias said:
yes that is the question
I am still thinking of this Stereolith thing and Stereolith-like setup (SLS)
the one You have written about:
Elias said:
what do You think?
it is not crosstalk cancelled setup but perhaps negative effects of crosstalk are sufficiently diminished?
best regards!
graaf
Hello,
Not so bad, actually
Are you sure the aim is different or it is out of context? Namely, If we want to perceive a copy of the original sound event (via a recording), then we must perceive the original SPACE also.
And also to make the space perception to sound most real, it may be beneficial to have a sound space where sounds made inside the listening space become a part of the perceived original space. Thus the method you describe using mics and speakers on the wall IS NOT out of context at all. In fact pretty tempting idea.
- Elias
mige0 said:Roughly a dozen each side.
Not so bad, actually
Are you sure the aim is different or it is out of context? Namely, If we want to perceive a copy of the original sound event (via a recording), then we must perceive the original SPACE also.
And also to make the space perception to sound most real, it may be beneficial to have a sound space where sounds made inside the listening space become a part of the perceived original space. Thus the method you describe using mics and speakers on the wall IS NOT out of context at all. In fact pretty tempting idea.
- Elias
The discussion goes around in circles. If anybody is interested in the facts:
Benjamin, AES Convention Paper 6968, 2006
Aarts, JAES 48 #3, 2000
Lee, AES Convention Paper 6142, 2004
Holland, AES Convention Paper 4581, September 1997
Makita, EBU Review #73, 1962
Sande, JAES 27 #5, 1955
In German:
Wendt, Rundfunktechnische Mitteilungen Band 8, 1964
Ortmeyer "Mitteilungen aus dem Heinricht-Hertz Institut ...", 1965
Best, Marku
Benjamin, AES Convention Paper 6968, 2006
Aarts, JAES 48 #3, 2000
Lee, AES Convention Paper 6142, 2004
Holland, AES Convention Paper 4581, September 1997
Makita, EBU Review #73, 1962
Sande, JAES 27 #5, 1955
In German:
Wendt, Rundfunktechnische Mitteilungen Band 8, 1964
Ortmeyer "Mitteilungen aus dem Heinricht-Hertz Institut ...", 1965
Best, Marku
gedlee said:
(sorry for the delay in response, life intruded.
)rather than make much about this see:
- page 5 paragraph 4 in your advertisement.
- your post here:
http://db.audioasylum.com/cgi/m.mpl?forum=hug&n=98035&highlight=summa&r=
..finally (a separate issue), consider that at the very least Lynn does admire (and has "extolled the virtues of OB's") - and has heard the Summa's.
(same data, different perspective.
)..as for an OB's deficiency with respect to edge diffraction, that topic has been covered better elsewhere. What it has NOT seemed to polarize (in any discussion I've found) - is any serious negative aspect to the perception of listeners (..so far its a moot point).
This all highlights the simple fact though that even irrespective of differences on what is or is not "practical", there is no "magic formula" for success with respect to the perception of music reproduction over varying loudspeaker designs/executions. (..also see the subjective responses of the recent RMAF 2008 thread.)
I enjoy Lynn Olsen's writing too and I'm glad he's posting here. Who am I to say anything if it's not nice but he maintains that he can compare a sound he heard 40 years ago in a theater with a stereo he heard today. To me that's preposterous, even seconds are a problem in comparing sound quality between speakers. Memories are mostly imagination and curve fitting. We continually shape the story to jive with our others because we're cursed by concepts of causality and "fairness" or "rightness". When it makes too much sense you're probably hoping.
Back to the topic of the thread, we're all reading Toole's book right? He's pushing wide dispersion but doesn't think any of the reflections in a small room are late enough to add to envelopment like the omni guys are claiming. (image width yes but not envelopment) Markus posted that frequency drawing but it didn't have time scales, the whole envelopment range is supposed to need a huge room or digitally delayed echoes.
To Earl's comment earlier about the first reflection, Toole doesn't lump them all together he actually goes into a lot of detail about the first reflection and still comes up with an ambiguous answer. Most listeners tested prefer a very strong early reflection, comb filter and all but musicians and recording engineers prefer very little. What kind of science is going to say who's "right" and it would seem to be a real problem that they're hearing something dramatically different than their listeners. I don't even want to admit how many guys I know who buy into ns10s and other deliberately "bad" monitors in dead rooms.
It seemed to me Toole was saying absorb the first reflection or don't depending on your preference and existing expectations/need but if you're going to do it absorb the whole thing, which is near impossible and why I was trying to get people to look at that BAD panel earlier. The off axis spectrum from the speaker is going to be heavily tilted towards the bass already, adding an absorber that is only effective down to 500hz would seem to be doubling the bass heavy bias. Put that mask on it and it absorbs MORE bass than the raw absorber and reflects the higher frequencies. That doesn't sound like a win? I noticed D'Antonio was mentioned in the book too, do you know him Earl?
Back to the topic of the thread, we're all reading Toole's book right? He's pushing wide dispersion but doesn't think any of the reflections in a small room are late enough to add to envelopment like the omni guys are claiming. (image width yes but not envelopment) Markus posted that frequency drawing but it didn't have time scales, the whole envelopment range is supposed to need a huge room or digitally delayed echoes.
To Earl's comment earlier about the first reflection, Toole doesn't lump them all together he actually goes into a lot of detail about the first reflection and still comes up with an ambiguous answer. Most listeners tested prefer a very strong early reflection, comb filter and all but musicians and recording engineers prefer very little. What kind of science is going to say who's "right" and it would seem to be a real problem that they're hearing something dramatically different than their listeners. I don't even want to admit how many guys I know who buy into ns10s and other deliberately "bad" monitors in dead rooms.
It seemed to me Toole was saying absorb the first reflection or don't depending on your preference and existing expectations/need but if you're going to do it absorb the whole thing, which is near impossible and why I was trying to get people to look at that BAD panel earlier. The off axis spectrum from the speaker is going to be heavily tilted towards the bass already, adding an absorber that is only effective down to 500hz would seem to be doubling the bass heavy bias. Put that mask on it and it absorbs MORE bass than the raw absorber and reflects the higher frequencies. That doesn't sound like a win? I noticed D'Antonio was mentioned in the book too, do you know him Earl?
I realized after that my last question is naive. To us hobbyists it seems like there's a very limited number of people working and publishing things in this field so you must all run into each other, but I know from my own career that a limited number of players only makes it less likely that you'll have met each other.
Page 97, Fig. 7.1: delay < 80 ms = image shift, source broadening; delay > 80 ms = envelopment
Tools advocats absorption behind the speaker and behind the listener. In stereo there should be NO absorption on the first-reflection points at side walls to increase spaciousness. In multichannel he says it would be optional.
poptart said:
markus76 said:
so it seems that regarding first reflections Toole's opinion is in perfect agreement with David Moulton opinion expressed in an 1999 interview: http://www.moultonlabs.com/more/nick_batzdorf_interview/
poptart said:
markus76 said:
so perhaps we can agree that side reflections in a typical room while cannot increase envelopment still can and do increase spaciousness which is also a very good thing because this spaciousness increase realism of sound reproduction
(not necessarily accuracy)
best regards!
graaf
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