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Beyond stereo?


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6 hours ago, esldude said:

Some other articles which are relevant to the topic.

 

http://www.desena.org/multichannel/Ambisonics_2_Int_Symp_2010.pdf

 

Describes and compares two versions of Johnston and Lam's perceptual sound field methods and Ambisonics.

 

http://www2.ensc.sfu.ca/~ljilja/cnl/guests/cvetkovic.pdf

 

A powerpoint presentation of related material.  The video of that presentation is embedded below.

 

Finally a paper from earlier this year.

 

http://epubs.surrey.ac.uk/813317/13/hacihabiboglu_etal2017.pdf

 

Good catch, forgot about the first one and the last one had not seen, checking out...

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1 hour ago, STC said:

 

I won't comment of what Ralph said, although I understand his message.

 

In stereo recordings, all the ambiance would not be captured. In fact, I think they probably limit the amount of ambiance in the recordings. Ambiance should come from multi direction. If you try to capture the ambiance than the resultant sound would be muddy and congested like the videos I posted earlier. Although, the sound was congested the actual sound in the room is totally different. The next time, when you visit a concert hall, look around and see where they place the microphones. 

 

 

 

 

You are missing the important point there in the cello chart, i.e which of the radiating sound will reach you and which of other sound will reach you ears after bouncing of the surface. Then what will be ratio of the loudness of each reflected sound to the ears. And which of the reflection are important. 

 

To know more of the ambiance, you need to understand impulse response for the reproduction of ambiance. And there are few types of impulse response. You can make your own impulse response but if you go to pro sound website you can buy true stereo impulse response of various concert halls. For example, I use the 32 IR of St.Cecilia. These are true stereo IR where the location at 90 degrees at 23 degrees elevation of the left side hall is created in stereo. This IR will be used to reproduce the effect by way of convolution, of the sound bouncing of the wall from that direction. You have many IRs for right and left side, including ceiling reflection, back and front. 

 

Depending on your room reflection, this convoluted sound may be slightly different but since my room sound is practically zero, I get the extended reverb of without coloration because I am replacing my walls with the St.Cecilia. How accurate is this sound to St.Cecilia's? or is my room sound without these convoluted speakers will be more pleasant to listen? Only you can answer that after listening to such setup.

 

OTOH, you need not use these additional ambiance for all the recordings as some where meant to listen with very little ambiance. Paravotti would sound better with ambiance but a lullaby probably fares better without the ambiance.

 

I read somewhere that George Martin when he saw two speakers the first time for recordings " he asked why would they want to do that".

 

 

i don't think you read Ralph's quote.

 

Up until recently I used to live in front of this concert hall; you can see the single pair of mics is hanging from the canopy:

 

gulbenkian-grande-audit%C3%B3rio-stage-f

 

This setup was used for broadcasting live concerts by many radios all over Europe, and some still continue to do so.

It sounds a bit like...live.

 

I agree that in stereo recordings, all the ambiance would not be captured.

And unfortunately many record companies close- and multi-mic and those recordings will have even less ambience.

But if the stereo recording did not capture all the ambience then there is no way to play it back with or without convolution/processing.

 

Pentatone multi-mic'ed Sa Chen in that same hall.

I listened to her play the week they made the recording and I can't really say that I like what they did in my two-channel setup.

Have a look at Pentatone's mic setup:

 

 

 

"Science draws the wave, poetry fills it with water" Teixeira de Pascoaes

 

HQPlayer Desktop / Mac mini → Intona 7054 → RME ADI-2 DAC FS (DSD256)

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This is my favorite local (USF), which can vary significantly with the adjustable cloud over the stage

1259-Music-Concert-Hall-02_lrg.jpg

 

Only someone who has never been into a concert hall, or a madman, could claim 2 frontal plane wave generators can recreate this (physically, not just perceptually impossible of course).

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3 minutes ago, AJ Soundfield said:

This is my favorite local (USF), which can vary significantly with the adjustable cloud over the stage

1259-Music-Concert-Hall-02_lrg.jpg

 

Only someone who has never been into a concert hall, or a madman, could claim 2 frontal plane wave generators can recreate this (physically, not just perceptually impossible of course).

 

I don't think anyone saying that. Almost all agree multi channel is the way. It is impossible to recreate realism with two channels only. 

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9 minutes ago, STC said:

 

I don't think anyone saying that. Almost all agree multi channel is the way. It is impossible to recreate realism with two channels only. 

 

Don't you mean soundfield realism, or source/space representation?

"Science draws the wave, poetry fills it with water" Teixeira de Pascoaes

 

HQPlayer Desktop / Mac mini → Intona 7054 → RME ADI-2 DAC FS (DSD256)

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7 minutes ago, STC said:

 

I don't think anyone saying that.

Not in this thread, no, but it was spawned from the morass of the other where such claims were being made.

Plus it's not to hard to find audiophiles discussing some magic widget and it's "accuracy" to some fantasy of 2ch rendering in their minds.

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18 minutes ago, AJ Soundfield said:

This is my favorite local (USF), which can vary significantly with the adjustable cloud over the stage

1259-Music-Concert-Hall-02_lrg.jpg

 

Only someone who has never been into a concert hall, or a madman, could claim 2 frontal plane wave generators can recreate this (physically, not just perceptually impossible of course).

 

Tried to get John Zorn to play here but administration couldn't come up with the money. Nice space but not utilized very well as far as I can see.

 

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3 hours ago, cfisher said:

 

Tried to get John Zorn to play here but administration couldn't come up with the money. Nice space but not utilized very well as far as I can see.

 

Shame about Zorn, but I'm perfectly ok with the performers they do have there, as I quite enjoy the sound as well.

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14 hours ago, STC said:

 

I think there was another AES paper. But I understand your point. As far as I know crosstalk cancellation only applies to certain frequency range and around 20 or 30dB depending on the algorithm. So you could be right. 

It is actually less than that.

 

6 hours ago, Ralph Glasgal said:

If you look at the AES paper on RACE, you will see that it is normal to achieve a channel separation of 10 dB and also recover all the inter channel time difference that is on a track.  For music or movies these numbers are more than one achieves in a concert hall or any pop concert.  Normal values of level difference at the ears at a concert seldom exceed 5 dB and the time difference in nature cannot exceed 700 microseconds since that is the delay from ear to ear.  There is also the improvement in pinna function when the speakers are moved closer together.

 

If you want a bee buzzing at your ear you need 10 to 20 dB of level difference at the ears and that is hard to achieve without head tracking and measuring speakers, etc.  So for virtual reality in military or similar applications you can go over board, but for home listening such high levels of crosstalk cancellation or special recordings that actually have LDs of 10 dB or more are not necessary.

 

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15 hours ago, semente said:

 

i don't think you read Ralph's quote.

 

Up until recently I used to live in front of this concert hall; you can see the single pair of mics is hanging from the canopy:

 

gulbenkian-grande-audit%C3%B3rio-stage-f

 

This setup was used for broadcasting live concerts by many radios all over Europe, and some still continue to do so.

It sounds a bit like...live.

 

I agree that in stereo recordings, all the ambiance would not be captured.

And unfortunately many record companies close- and multi-mic and those recordings will have even less ambience.

But if the stereo recording did not capture all the ambience then there is no way to play it back with or without convolution/processing.

 

Pentatone multi-mic'ed Sa Chen in that same hall.

I listened to her play the week they made the recording and I can't really say that I like what they did in my two-channel setup.

Have a look at Pentatone's mic setup:

 

 

 

This sounded as if everything was full left or full right over headphones.   Only when she speaks is there much of a center.

 

 

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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8 minutes ago, STC said:

 

Is this Youtube a binaural recording?

 

 

I don't know.  I would say not from the sound of it.

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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1 minute ago, esldude said:

I don't know.  I would say not from the sound of it.

 

Hard left and right sounds normal to me. I don't listen with headphones except when looking for artifacts but after spending several hours with them I now sense the sound to be more around my head then what I usually perceive with binaural recordings. 

 

If if I were to play the binaural recording and doing A/B with the speakers the soundscape appears the same but prolonging listening with the same binaural recording with headphones reveals inside head feeling. Strange. I suspect my brain is creating the space based on what I heard over the speakers when I do quick AB.  

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4 hours ago, esldude said:

This sounded as if everything was full left or full right over headphones.   Only when she speaks is there much of a center.

 

 

 

I didn't add the video for sound assessment but just to illustrate mic positioning, although the SACD does sport both 2.0 and 5.1 versions.

Perhaps you can assess sound quality with this other video which I presume was recorded in the two days with audience but the sound may be from the Redbook layer:

 

 

"Science draws the wave, poetry fills it with water" Teixeira de Pascoaes

 

HQPlayer Desktop / Mac mini → Intona 7054 → RME ADI-2 DAC FS (DSD256)

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9 hours ago, STC said:

It is actually less than that.

 

 

Thanks, that's in line with physics a I understand it.

I'm still pouring through the links esldude provided but there is some interesting stuff in the last one, as I'm recognizing many of the references.

Of course, as I noted earlier, the vast majority of music is 2ch, so my focus is mainly on how to maximize that.

I personally use a system (loosely) based on this for that end.

But I'm PSR et al ready, were such recordings and decoders to materialize.

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13 minutes ago, STC said:

 

You could have mentioned earlier and saved my time combing through his website ?

 

 

Hey, Ralph sent us on this goose chase! x-D

 

I was curious enough to dig a bunch too LOL. I'm always interested in finding things I don't, or may not quite understand. I was also puzzled by early his head tracking/HRTF response to my comment, but again, I think there is clarification now. I would still like to hear a good 22ch demo :)

Not too many of those around these parts, or any audio show I've attended

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Quote

Ralph Glasgal said:

 

In a plain stereo system in a live room, everything about a speaker will make a difference but there is no real fix available due to human hearing properties and that the pattern of peaks and dips that a stereo system produces will be different for every listener, every speaker and every angle (60,61,59,etc.) and so there can be no universal fix that would be stable.

Well, there are methods for producing a wider listening area with stereo loudspeakers 

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On ‎6‎/‎20‎/‎2017 at 9:16 AM, AJ Soundfield said:

That might be enough, so I don't want to belabor a minor point.

Just noticed your link, interesting system you have there. Too many speakers for me, and I sell them! :D

The AES papers by me and Tsai Yi Wu show the amount of separation achieved by using RACE with real speakers.  You can get up to 10 dB at frequencies where it is most useful to the brain.  It is certainly much better ILD and ITD than can be obtained with any 60 degree speaker system.  The point is not that it is perfect compared to real life but that it is easily much better than standard stereo when playing the same existing 2.0 media.  If you demo your speakers using RACE you will sell a lot more of them.

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1 minute ago, Ralph Glasgal said:

If you demo your speakers using RACE you will sell a lot more of them.

Thanks Ralph, appreciate that.:D

The problem is that most folks don't want or most like can't have 22 speakers in their listening room. Bless those who can!

Btw, some cross posting here as you might notice, since we were large "polluting" the other thread.

Thanks for the info so far, I'm still reading and digesting some of your work

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