Beyond stereo?

[semente]

Just now, AJ Soundfield said:

Well there you have it

 

Yes. 

 

One of Ralph's posts a couple of days provides good information on what I mean.

[AJ Soundfield]

2 minutes ago, semente said:

Yes. 

One of Ralph's posts a couple of days provides good information on what I mean.

So you didn't mean this

Quote

will not be able to provide a realistic holographic soundfield

Because that does involve listening.

Perhaps you could make up your mind?

[semente]

7 minutes ago, AJ Soundfield said:

So you didn't mean this

Because that does involve listening.

Perhaps you could make up your mind?

 

I meant realistic as in mimicking the radiation of a violin, which as shown previously in pics.

Yes a pair of mics does capture both direct and reflected sound but reproduction is then a) is subject to the radiation pattern of the speakers and b) interacts or is coloured/muddled by listening room reflections/interaction (anechoic listening could help). 

 

Perception studies are about listening and listening doesn't help here. 

[AJ Soundfield]

1 minute ago, semente said:

I meant realistic as in mimicking the radiation of a violin, which as shown previously in pics.

As long as the encoding captures the soundfield as 2 ears/head would hear said radiated polar field, that is irrelevant.

Once again, it appears you are not reading any of the literature.

Quote

Yes a pair of mics does capture both direct and reflected sound

 

A pair of mics is woefully inadequate. If you read, you would have seen Perceptual Soundfield Reconstruction techniques use 7 mics. The specific directional characteristics and reasons are explained.

Indeed one does want to capture both onset (aka direct) and indirect fields.

 

Quote

Perception studies are about listening and listening doesn't help here.

 I'm afraid you are quite lost here. That's what this thread is all about. If you want to know whether you have realistically encoded the violins radiated sound, listening tests are the final arbiter.

[STC]

3 minutes ago, semente said:

 

I meant realistic as in mimicking the radiation of a violin, which as shown previously in pics.

Yes a pair of mics does capture both direct and reflected sound but this then a) is subject to the radiation pattern of the speakers and b) interacts or is coloured/muddled by listening room reflections/interaction (anechoic listening could help). 

 

 

The ambiance if captured fully as heard by the ears would make the recording sound congested and muddy. In live performance the ambiance originates from multiple reflected surface. You shouldn't reproduce the ambiance ( even it is possible to record them) in the recording because all the different direction cues will now originate from the two speakers. Whatever ambiance that you hear in the recording is limited so that it would not  overly distort the sound when the room acoustics  add its own ambiance. 

 

 

[semente]

1 minute ago, AJ Soundfield said:

As long as the encoding captures the soundfield as 2 ears/head would hear said radiated polar field, that is irrelevant.

Once again, it appears you are not reading any of the literature.

A pair of mics is woefully inadequate. If you read, you would have seen Perceptual Soundfield Reconstruction techniques use 7 mics. The specific directional characteristics and reasons are explained.

Indeed one does want to capture both onset (aka direct) and indirect fields.

 

 I'm afraid you are quite lost here. That's what this thread is all about. If you want to know whether you have realistically encoded the violins radiated sound, listening tests are the final arbiter.

 

Sorry, I'm not following you.

99% of your interventions dismiss listening as subjective except with reference to Toole's research and when it suits you.

[semente]

4 minutes ago, STC said:

 

The ambiance if captured fully as heard by the ears would make the recording sound congested and muddy. In live performance the ambiance originates from multiple reflected surface. You shouldn't reproduce the ambiance ( even it is possible to record them) in the recording because all the different direction cues will now originate from the two speakers. Whatever ambiance that you hear in the recording is limited so that it would not  overly distort the sound when the room acoustics  add its own ambiance. 

 

 

 

That is what I have been saying. 

But it's not just limited by the recording speakers and speaker/room interaction are also a factor here.

More channels and processing improve spatial reproduction but in the end the method is still flawed.

[AJ Soundfield]

4 minutes ago, semente said:

99% of your interventions dismiss listening as subjective except with reference to Toole's research and when it suits you.

Thanks for confirming you haven't read a single link. They are important to the discussion

[AJ Soundfield]

3 minutes ago, semente said:

More channels and processing improve spatial reproduction but in the end the method is still flawed.

Hopefully you are not referring to listening here either

[semente]

Imagine a drop in the first centre third of a rectangular glass box half-filled with water and a listener floating in the other third.

A first ripple will hit the listener and then many other ripples will ensue reflected by the walls - the ambience or spatial cues.

This is a simplified model of course because it's only working in a single horizontal plane.

 

If you try to reproduce this with say four corner speakers and a central one you will have to contend with the listening room added reflections, with the dispersion pattern of the loudspeakers and with the interaction between the speakers' soundfields.

[semente]

18 minutes ago, AJ Soundfield said:

Thanks for confirming you haven't read a single link. They are important to the discussion

 

Could you please provide me with the relevant links you are referring to?

You have posted quite a few in this and the other thread that has similar content.

[AJ Soundfield]

2 hours ago, semente said:

 

Could you please provide me with the relevant links

Absolutely

https://www.computeraudiophile.com/forums/topic/32135-beyond-stereo/#comment-676805

[gmgraves]

9 hours ago, AJ Soundfield said:

 

A pair of mics is woefully inadequate. If you read, you would have seen Perceptual Soundfield Reconstruction techniques use 7 mics. The specific directional characteristics and reasons are explained.

Indeed one does want to capture both onset (aka direct) and indirect fields.

 

I'm afraid that you are wrong sir. A pair of the right mikes in the hands of someone who knows what they are doing, are very much "adequate". And I have made enough recordings using only two mikes to know.

[AJ Soundfield]

1 hour ago, gmgraves said:

I'm afraid that you are wrong sir. A pair of the right mikes in the hands of someone who knows what they are doing, are very much "adequate". And I have made enough recordings using only two mikes to know.

Right, if I got to grade all my own tests I'd be a straight A student. 

2 mics are woefully inadequate for any semblance of soundfield reconstruction. That is a physical fact, not conjecture.

At best, one can do a binaural recording for headphones. For speakers and listeners in a room, forget it.

[gmgraves]

47 minutes ago, AJ Soundfield said:

Right, if I got to grade all my own tests I'd be a straight A student. 

2 mics are woefully inadequate for any semblance of soundfield reconstruction. That is a physical fact, not conjecture.

At best, one can do a binaural recording for headphones. For speakers and listeners in a room, forget it.

 

I do it with MS miking using figure-of-eight microphones, but one can also do it with crossed figure-of-eights and get really nice ambience using spaced omnis (but this requires a fairly live venue). At any rate, I find two carefully chosen and well set-up microphones are more than adequate to make an ambience-rich 2-channel recording.

[STC]

50 minutes ago, AJ Soundfield said:

Right, if I got to grade all my own tests I'd be a straight A student. 

2 mics are woefully inadequate for any semblance of soundfield reconstruction. That is a physical fact, not conjecture.

At best, one can do a binaural recording for headphones. For speakers and listeners in a room, forget it.

 

True but two channels are also adequate. Binaural is two channel recording. 

[AJ Soundfield]

14 hours ago, gmgraves said:

 

I do it with MS miking using figure-of-eight microphones, but one can also do it with crossed figure-of-eights and get really nice ambience using spaced omnis (but this requires a fairly live venue). At any rate, I find two carefully chosen and well set-up microphones are more than adequate to make an ambience-rich 2-channel recording.

A 2 mic sample of any soundfield is inadequate to capture both onset and diffuse portions, so that any realistic rendering with loudspeakers can occur. Again, binaural doesn't work with loudspeakers and is inferior to actual soundfield reconstruction rendering methods. I would post all the links yet again, but we are at Einsteins insanity definition here.

The characteristics of the diffuse portion cannot be played back simultaneously with plane wave onsets and be perceived as one would live. That is a physical fact, not conjecture.

[AJ Soundfield]

14 hours ago, STC said:

 

True but two channels are also adequate. Binaural is two channel recording. 

Oxymoron 

 

Binaural only works with headphones and headphone are certainly not going to be confused with the visceral impact of reality.

[AJ Soundfield]

Since folks are having trouble reading links

Quote

In the usual stereo audio presentation, a partial sound stage consisting primarily of the front elements of the sound stage is created by two channels, either sampled from several microphones set in the original sound field or more often by a mixdown of many microphones placed both in proximity to the performers and out in the hall to capture the ambience. The information presented by the two channels, in either case, is a small fraction of the information in the original sound field. Additionally, this fraction is presented to the front of the listener. The presentation does not create an envelopment experience, where one is immersed in the original sound field, as the information is not present. While some processors mimic the effect, such effects are not based on the actual venue but rather on some hypothetical model of a venue. : In holographic or auralized two-channel presentation, a presumed human head-related transfer function (HRTF) is used to create an impression of sound arising from other than the front of the listener. This works well in headphones or with interaural cancellation for one listener facing directly ahead and on the central axis between the loudspeakers. This method can, with some difficulty, produce an immersive effect for one point in the sound field, assuming that the subject maintains the proper head position, and the subject's head has an HRTF like that of the presumed functions. The ultimate form of this is, of course, binaural recording, where an actual head model is used to capture the information for one head location. : Beyond two-channel presentation, one can think of analytically capturing an original sound field to some degree of accuracy. This would require the use of many channels, perhaps placed in a sphere about the listener's head in the simplest form, requiring very high data rates (1000 to : 10 000 channels, perhaps) and creating a very high probability of influencing the sound field in the space with the microphones and the supporting mechanisms. As a result this technique is currently infeasible, and is likely to remain infeasible, for basic physical reasons as well as data-rate reasons, and actual analytic capture of the spatial aspects of a sound field in this fashion is unlikely.

 

[NOMBEDES]

Wow. I have problems with WAF just for four speakers.  Unless you have unlimited space in your backyard for an underground anechoic chamber to be constructed, good luck.

[AJ Soundfield]

31 minutes ago, NOMBEDES said:

Wow. I have problems with WAF just for four speakers.  Unless you have unlimited space in your backyard for an underground anechoic chamber to be constructed, good luck.

Great news for you:

http://www.aes.org/tmpFiles/elib/20170625/13880.pdf

Figure 5

Quote

If two pairs of loudspeakers are arranged in the following manner — the front pair at an angle of around 60 degrees and the rear pair at an angle of 120 to 180 degrees — four loudspeakers can reproduce the spatial impression of a diffuse sound field.

 

[Ralf11]

2 ears

2 mics

2 speakers

 

that ol' time religion is good enuff fer me

[gmgraves]

1 hour ago, Ralf11 said:

2 ears

2 mics

2 speakers

 

that ol' time religion is good enuff fer me

+1!

[gmgraves]

20 hours ago, AJ Soundfield said:

Right, if I got to grade all my own tests I'd be a straight A student. 

2 mics are woefully inadequate for any semblance of soundfield reconstruction. That is a physical fact, not conjecture.

At best, one can do a binaural recording for headphones. For speakers and listeners in a room, forget it.

 

4 hours ago, AJ Soundfield said:

A 2 mic sample of any soundfield is inadequate to capture both onset and diffuse portions, so that any realistic rendering with loudspeakers can occur. Again, binaural doesn't work with loudspeakers and is inferior to actual soundfield reconstruction rendering methods. I would post all the links yet again, but we are at Einsteins insanity definition here.

The characteristics of the diffuse portion cannot be played back simultaneously with plane wave onsets and be perceived as one would live. That is a physical fact, not conjecture.

 

AJ, from your picture, I'd venture to say that I've been doing live, location recording of classical music and jazz longer than you've been alive. You are entitled to your opinion, but my experiences tell me otherwise. I guess we're going to have to agree to disagree on this point. 

[semente]

1 hour ago, Ralf11 said:

2 ears

2 mics

2 speakers

 

that ol' time religion is good enuff fer me

 

7 minutes ago, gmgraves said:

+1!

 

+another 1