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What is audio meant to do?

andreasmaaan

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#1
An exchange in another thread got me to thinking about what we hope an ideal audio reproduction system is supposed to do, which I think is a deeply problematic question, with implications for decisions about how we design and use both recording and reproduction systems.

The statement I found interesting (from @FrantzM) was:
Audio reproduction involves science, lot of it. We don't know it all yet... There is still much to learn. We aren't at a point where our audio systems fool us into believing that a real even is taking place in our home. That is at the bottom the goal of High Fidelity and Science will lead the way ...
I agree completely with the first part of the quote. But I find the second part (which I've italicised) problematic. The implication of this statement seems to be that:

The goal of an ideal reproduction system is to reproduce a performance that would be audibly indistinguishable from the original.***

At face value, this seems to be a legitimate ultimate goal of audio reproduction. But in my opinion, it's flawed.

A reproduction system does not receive a performance and then reproduce it; rather, it receives a signal containing a recording of the original performance. So the first thing to note is that this recording is not itself the original performance.

Moreover, even if a recording is captured by a transparent microphone (or two if we make it binaural) and stored on a transparent recording medium, this recording cannot discriminate between the direct sound and the reflected sound at the point in the performance space at which the microphone(s) is situated.

And it is this mixture of direct and reflected sound which becomes the signal that is then reproduced by a speaker (or headphones or multiple speakers).

How, in light of this, can a reproduction system hope to fulfil the goal of reproducing a "performance" in a way that is audibly indistinguishable from the original?

In the original performance, we have a mic receiving direct and reflected sound from different points all around it in the performance space. Then, on playback, we have a speaker reproducing all those sounds from one point in space.

And if this is fundamentally impossible, what goal do we set for an ideal reproduction system? What are we trying to achieve beyond the specific goals of inaudible distortion etc. etc? If an ideal reproduction system can't reproduce an original performance, what is it supposed to be able to do?

***Apologies to @FrantzM if I'm reading your statement incorrectly.

EDIT: sentence in bold added for clarity.
 
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andreasmaaan

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#2
On a side note, I can think of only one possible way in which a recording might be able to be said to capture a performance according to the model I discussed in the OP. This would be when the recording itself is taken in an anechoic chamber.

I've never heard a recording taken in an anechoic chamber - has anyone hear ever heard or made one? I imagine it would sound as unnatural as the experience of being in an anechoic chamber. Or perhaps after an adjustment period, you'd get used to the way the sound you hear from your speaker(s) contains only reflections from the room your speakers are in.
 

Wombat

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#3
An exchange in another thread got me to thinking about what we hope an ideal audio reproduction system is supposed to do, which I think is a deeply problematic question, with implications for decisions about how we design and use both recording and reproduction systems.

The statement I found interesting (from @FrantzM) was:



I agree completely with the first part of the quote. But I find the second part (which I've italicised) problematic. The implication of this statement seems to be that:

The goal of an ideal reproduction system is to reproduce a performance that would be audibly indistinguishable from the original.***

At face value, this seems to be a legitimate ultimate goal of audio reproduction. But in my opinion, it's flawed.

A reproduction system does not receive a performance and then reproduce it; rather, it receives a signal containing a recording of the original performance. So the first thing to note is that this recording is not itself the original performance.

Moreover, even if a recording is captured by a transparent microphone (or two if we make it binaural) and stored on a transparent recording medium, this recording cannot discriminate between the direct sound and the reflected sound at the point in the performance space at which the microphone(s) is situated.

And it is this mixture of direct and reflected sound which becomes the signal that is then reproduced by a speaker (or headphones or multiple speakers).

How, in light of this, can a reproduction system hope to fulfil the goal of reproducing a "performance" in a way that is audibly indistinguishable from the original?

And if this is fundamentally impossible, what goal do we set for an ideal reproduction system? What are we trying to achieve beyond the specific goals of inaudible distortion etc. etc? If an ideal reproduction system can't reproduce an original performance, what is it supposed to be able to do?

***Apologies to @FrantzM if I'm reading your statement incorrectly.
I think you missed the word ideal.

At present Dr. Toole is constructing a very-many discrete channels sound-room to get closer to that ideal.

I don't aspire to audio beyond a good stereo system in a 'normal' room. How long is a piece of string?
e41b.png
 
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Kal Rubinson

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#5
I've never heard a recording taken in an anechoic chamber - has anyone hear ever heard or made one? I imagine it would sound as unnatural as the experience of being in an anechoic chamber. Or perhaps after an adjustment period, you'd get used to the way the sound you hear from your speaker(s) contains only reflections from the room your speakers are in.
 

RayDunzl

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#7

andreasmaaan

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#8
I think you missed the word ideal.

At present Dr. Toole is constructing a very-many discrete channels sound-room to get closer to that ideal.

I don't aspire to audio beyond a good stereo system in a 'normal' room. How long is a piece of string? View attachment 14476
Yeh, I'm very happy with stereo in pretty normal rooms atm too. I'm interested in this more from a philosophical perspective, although I reckon thinking through these questions can very occasionally lead to useful and interesting practical ideas.
 

Sal1950

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#9
An exchange in another thread got me to thinking about what we hope an ideal audio reproduction system is supposed to do, which I think is a deeply problematic question, with implications for decisions about how we design and use both recording and reproduction systems.

The statement I found interesting (from @FrantzM) was:


I agree completely with the first part of the quote. But I find the second part (which I've italicised) problematic. The implication of this statement seems to be that:

The goal of an ideal reproduction system is to reproduce a performance that would be audibly indistinguishable from the original.***

At face value, this seems to be a legitimate ultimate goal of audio reproduction. But in my opinion, it's flawed.

A reproduction system does not receive a performance and then reproduce it; rather, it receives a signal containing a recording of the original performance. So the first thing to note is that this recording is not itself the original performance.

Moreover, even if a recording is captured by a transparent microphone (or two if we make it binaural) and stored on a transparent recording medium, this recording cannot discriminate between the direct sound and the reflected sound at the point in the performance space at which the microphone(s) is situated.

And it is this mixture of direct and reflected sound which becomes the signal that is then reproduced by a speaker (or headphones or multiple speakers).

How, in light of this, can a reproduction system hope to fulfil the goal of reproducing a "performance" in a way that is audibly indistinguishable from the original?

And if this is fundamentally impossible, what goal do we set for an ideal reproduction system? What are we trying to achieve beyond the specific goals of inaudible distortion etc. etc? If an ideal reproduction system can't reproduce an original performance, what is it supposed to be able to do?

***Apologies to @FrantzM if I'm reading your statement incorrectly.
I always felt that the opposite would be the ideal.
That is that the listening room should be as close to anechoic as possible.
The only "room" that should be heard is that one the recording.
Closed back headphones can come close but fail on the stereoscopic part, they just don't soundstage correctly unless recorded binuarly. But I've never heard one that worked really well.
 

Guermantes

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#10
I used to own a copy of this but it was unfortunately stolen in a break-in :mad:

I remember that the "anechoic" conditions were actually semi-anechoic due to the practical problems of trying to fit an orchestra in a truly anechoic chamber, so there was still some room sound though the RT60 was vanishingly short.
 

amirm

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#12
I have a saying: standardization is the enemy of innovation. Once we standardized on 2-channel audio, we put a lot of restrictions on ourselves for sound reproduction.
 

Blumlein 88

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#14
The goal is the Absolute Sound of being there.

However, we now understand that is an impossibility with straight stereo. So even the perfect fidelity to a stereo signal won't get the job done.

Of course, there is just put a smile on my face, let me enjoy the music, and make my foot tap. Not very much fidelity at all may accomplish that. Different goal.

The goal is whatever you say it is. And that will always be subjective.
 

DonH56

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#15
I actually prefer a room that is deader than most. It is fairly necessary in my case, and for most smaller rooms IME/IMO. When I have had much larger rooms in the past I have wanted much less room treatment. The recording captures the ambiance, one would hope, and my system's job is to recreate that without the added influence of my room. A strong counter-argument can be made, of course...

I listen and watch for enjoyment, and the more I get into the music or movie and the less into the gear the better. I have no hope of matching a live performance, though can come close to a studio, but that isn't really what I am after. I understand they are two different mediums, places, times... As when performing, you have to put the analytical side aside and focus on what matters. I work on mechanics in the practice room, measure my system when I am setting it up or wish to analyze it better, but in the end the performance, and how immersed I am in that performance, is what matters (as a performer or listener).

IMO - Don
 
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andreasmaaan

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#16
I always felt that the opposite would be the ideal.
That is that the listening room should be as close to anechoic as possible.
The only "room" that should be heard is that one the recording.
Closed back headphones can come close but fail on the stereoscopic part, they just don't soundstage correctly unless recorded binuarly. But I've never heard one that worked really well.
The problem (and I mean "philosophical problem" - I'm not saying one or the other sounds worse) is that a non-anechoic recording, even when reproduced in an anechoic room, results in the direct and reflected sounds - which radiated from different sources in the performance space - emanating from the same source (the speaker/s) in the room in which it is reproduced.
 

andreasmaaan

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#17
Interestingly, my general preference (which has nothing to do with the more abstract thoughts I put in the OP) is for a fairly reverberant listening room. But for this to work well IMO the room should be quite large.
 

Guermantes

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#18
The various aspects and practical capabilities of multi-channel envelopment have been brought up in a few threads here. I remember Dr Toole stating that you can make a small room sound big but can't make a big room sound small. That may also apply to a reverberant one.
 

andreasmaaan

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#20
The various aspects and practical capabilities of multi-channel envelopment have been brought up in a few threads here. I remember Dr Toole stating that you can make a small room sound big but can't make a big room sound small. That may also apply to a reverberant one.
I really need to get round to reading his book..
 
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