You keep talking about this "accurate playback system." So tell me, which speaker polar radiation pattern is accurate? Should the carpet on your listening room floor be 1" or 2" thick in order to provide accuracy? Which brand of diffusion panel on your back wall is the accurate one?
Those questions are very easy. The correct polar radiation pattern is the one that creates an even sound field from left to right, with a balanced phantom center.
The correct carpeting and diffusion panels are the ones that give you a balanced frequency response from the main listening position.
Those questions are very easy. The correct polar radiation pattern is the one that creates an even sound field from left to right, with a balanced phantom center.
The correct carpeting and diffusion panels are the ones that give you a balanced frequency response from the main listening position.
Those questions are very easy. The correct polar radiation pattern is the one that creates an even sound field from left to right, with a balanced phantom center.
The correct carpeting and diffusion panels are the ones that give you a balanced frequency response from the main listening position.
What is an "even sound field" in objective, measurable terms?
"Balanced frequency response from the main listening position"? You mean the in-room response including all reflections? What's the time window? Reflections out to how many ms? Is this more important than the portion of the impulse that contains no reflections (direct sound) or the anechoic chamber response? Can you provide an objective, absolute justification for all answers? What's the polar sensitivity pattern of the microphone you use to measure the frequency response? Can you justify all these choices objectively?
The solution is simple. Camera A reproduces shapes with more objective accuracy and Camera B reproduces colors with more objective accuracy. If you leave it at that, accuracy is entirely objective. The problem is not that the observers disagree about which camera is more accurate -- it's that each observer is using the word accuracy in a sloppy way. More precise language ("accurate color reproduction" or "accurate shape reproduction") resolves the entire problem.
I addressed this exact point in my post #95 before:
It is reasonable to say that setup X might reproduce rhythm more accurately than setup Y, but setup Y might reproduce tone more accurately than setup X. X gets rhythm right and Y gets tone right. A listener who focuses on rhythm might then both prefer X and say that X sounds more accurate. A listener who focuses on tone might say that Y is preferable and more accurate. Do we need to be able to decide who is correct and who is incorrect to say that accuracy is objective? No. We just say that X reproduces rhythm more accurately and Y reproduces tone more accurately and leave it at that. Both determinations are objective. Weighing them against each other to determine an ultimate "winner" brings in subjectivity.
So I think it is easier to accept that accuracy is objective if we do away with thinking of accuracy as being a single dimension. Not that you've said accuracy is a single dimension; this is just where the discussion seems to be going when I think about it.
You can only make this point because the example is so simple. Note that we could never make the objective statement about "color reproduction" or "shape reproduction" without investigating the situation. We would have to come to some understanding of how perception works for each person A and B, and we would have to acknowledge the differences. We would have to be able to precisely characterize the differences and correlate those with measurements of the camera's reproductions.
You may be underestimating the difficulty in measuring shape reproduction and color reproduction, reducing them to two numbers that can be compared. How do we determine how much one 2D shape deviates from another? There are unlimited possibilities. Which possibility corresponds most closely to person A's perception? Can we characterize person A while at the same time acknowledging the differences between person A and B? Or would our test methods involve experiments that treat test subjects all the same?
Here's the major problem in audio. When person's A and B disagree about which audio system is most accurate, some scientists response by saying they have different preferences. With that kind of attitude, the necessary investigation will never take place. These scientists don't even acknowledge the validity of "subjective accuracy" so how the hell are they going to care to investigate it?
Then you'll agree that recording and mixing primarily involve creative subjective decision making, and playing a CD on your stereo primarily involves objective accuracy.
I'm looking at the whole system. The miking influences the speaker configuration for greatest subjective accuracy.
I agree there are some people who treat the situation as you describe, but I don't trust them to be able to reproduce an original acoustic, musical event with subjective accuracy.
What is an "even sound field" in objective, measurable terms?
"Balanced frequency response from the main listening position"? You mean the in-room response including all reflections? What's the time window? Reflections out to how many ms? Is this more important than the portion of the impulse that contains no reflections (direct sound) or the anechoic chamber response? Can you provide an objective, absolute justification for all answers? What's the polar sensitivity pattern of the microphone you use to measure the frequency response? Can you justify all these choices objectively?
An even sound field from left to right is an even dispersion. If you slowly potted a tone from left to right, it would cross the room smoothly without changing in volume, particularly in the middle (phantom center).
Time delay isn't an issue in typical living rooms, only train stations and baseball stadiums. By the way, hall ambiences aren't measured in ms, they are measured in seconds. A typical concert hall will have a two second decay from the original sound to the point where the volume drops 60dB (the point that most acousticians use for measuring such things.)
A balanced frequency response from the main listening position means that a tone sweep throughout the audible spectrum remains at a consistent sound pressure level throughout. This is taking into account both the response of the speakers and the effects of the room on the sound they produce. You calibrate this through room treatment and equalization and measure it with an SPL meter, or just tune it by ear.
The sensitivity of any testing or measuring equipment used doesn't really need to be any better than human ears, but many are much better. So it isn't an issue.
And that's why you are completely missing the point. Some things in the chain are relevant to accuracy, and some things are relevant to subjective creativity. There are artists and craftsmen involved. It isn't all art. Certain things are technical in nature.
Miking is done to work well with calibrated speakers placed 8 to 10 feet apart in a normal listening/living room. If there weren't playback standards that recording techniques were designed to adhere to, you would need a different playback system for every recording. Chaos.
I've supervised sound mixes. Would you like me to tell you a little bit about how mixing stages are set up?
Originally Posted by raddle /img/forum/go_quote.gif
I agree there are some people who treat the situation as you describe, but I don't trust them to be able to reproduce an original acoustic, musical event with subjective accuracy.
You're assuming that recorded music is intended to exactly reproduce the live performance. It isn't. There are creative decisions in recording involved in translating the live event into a new creative work- the recording. Performances and recordings are two completely separate things. Each one has its own strengths and weaknesses that the sound engineer needs to address to optimize the end product. The exception to this would be binaural recordings designed for headphone listening, but those are the exception, not the rule.
A balanced frequency response from the main listening position means that a tone sweep throughout the audible spectrum remains at a consistent sound pressure level throughout. This is taking into account both the response of the speakers and the effects of the room on the sound they produce. You calibrate this through room treatment and equalization.
So you are saying that for accuracy the in-room response (gated out to how ms? you didn't answer me) is more important than the anechoic response? Are you neglecting the anechoic response entirely? What's your justification for these things in objective terms?
And that's why you are completely missing the point. Some things in the chain are relevant to accuracy, and some things are relevant to subjective creativity. There are artists and craftsmen involved. It isn't all art. Certain things are technical in nature.
It doesn't really matter what's artistic and what's technical.. there is an original event and a final result, and that result can be judged by its accuracy to the original.
You are describing a process which ignores subjective accuracy. That's fine, but I certainly wouldn't trust you to produce a recording that gets musical details right.
I'm a professional producer, not an "armchair expert". I've supervised many many recording sessions and sound mixes. I don't think you are a particularly good judge of whether I am qualified to do that or not. Sorry!
Edit: But it really is nice of me to be so patient explaining things to you, isn't it?
An anechoic chamber is a tool for measuring how speakers sound independent of room acoustics. No one has an anechoic chamber in their home, so yes, I do neglect that entirely. Accuracy is how your equipment performs in your living room.
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