gregorio
Headphoneus Supremus
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- Feb 14, 2008
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[1] I'm not an expert in any aspect of audio or electronics
[2] I have enough relevant science and engineering background to engage in discussions about measurements, test methodology, how science works, limits of theory, etc.
1. Yes, that's been clearly established.
2. You've actually established the exact opposite. You demonstrated that you didn't know that digital audio data is in fact just a measurement but worse still, you demonstrated that you didn't even know that a measurement could be represented as binary (digital information). How that's possible in this day and age, when it's taught at school, let alone in university, is mind boggling for someone claiming to have a formal, relevant science/engineering education! Clearly you do not and cannot engage in a discussion about measurements and the "limits of theory" as it applies to digital audio if you don't understand even the basics of how and what digital is. You continually deflect from this fact by casting aspersions on others and quoting cognitive errors, when you yourself have virtually no understanding of the subject. Dunning-Kruger taken to the extreme!
For the record, I am not a research scientist, I'm an audio engineer. I do not have a degree in the subject because when I started there were no degree courses in the subject, education in the subject was effectively by means of the apprenticeship model, so I'm not self-taught or rather, only partially self-taught. Ironically, that is why I was originally employed by the university in the first place, to design a degree course! My university (conservertoire) education was in the field of music performance, so as I did not have a degree in the specific subject area I had to undergo endless rounds of internal and external examinations, which eventually assessed my knowledge and certified me to teach students up to and including PhD level. In practise, I've been certified and employed as an expert in the field by universities, research scientists, industry bodies and a government, just to name a few and you've got what, a measly degree in an unrelated subject? However, I'm not a great fan of appeals to authority (and even less so with appeals to effectively ignorance!) and none of this is relevant most of the time here anyway, because we're often not talking about who is or is not currently a research scientist, we're talking about research that was done and dusted (and proven!) 200 years ago, 150 years ago in the case of electrical properties and 70 years ago in the case of digital audio!
[1] Most current studio recordings don't contain much musical information above 20 kHz.
[2] The reason for that is that most studio microphones have little response above 20 kHz.
[2a] (And most recording engineers don't expend any effort trying to record them or preserve them during the mix.)
[3] And the reason for that is that information above 20 Khz isn't considered to be useful because it is assumed that nobody can hear above 20 kHz.
[3a] Therefore, since the information is largely absent, and no attempt is made to preserve it when it is present, nobody is going to hear it.
[4] HOWEVER, this doesn't prove either way whether people would or would not hear content above 20 kHz IF IT WAS THERE.
[5] (Again, I'm not SPECIFICALLY claiming that it's audible or not... just that we haven't actually tested the possibility... we simply "go with the assumption".)
1. By and large true.
2. Also true.
2a. Not entirely true but again, by and large true.
3. Sort of true.
4. Correct, it doesn't by itself prove that.
5. And there we have it yet again! Some true or partially true statements followed by a completely false statement and a totally fallacious conclusion! You have in fact got it entirely backwards, we "go with the assumption" precisely because we HAVE "tested the possibility"! The reason we assume >20kHz content isn't useful is because ALL the evidence and practicalities of music recording creation demonstrates that it is NOT useful, while there's NO evidence to suggest that it might be, which incidentally is why most studio mics are designed to have little response above 20kHz!
[1] Generally microphones are chosen to "sound good" - which includes being able to pick up whatever frequencies contribute to that result.
[2] I have little doubt that, if tests were to find that "cymbals sound better when recorded with microphones whose response extends to 30 kHz".... We would soon see studio microphones, designed specifically for cymbals, whose response extends to 30 kHz... and sold specifically for recording cymbals.
[3] I've personally made very few recordings... And I've certainly never recorded a drum kit using a microphone whose response extends to 30 kHz "just to see if anyone thinks it sounds better"... Have you actually tried it?
1. Interesting, you do in fact have at least a very basic idea of why mics are chosen. Why then do you keep inventing scenarios and quoting mics which are contrary to this requirement? Hmmm!
2. Agreed, that's a logical idea, nothing wrong with it at all. However, in reality it's nonsense because we have done exhaustive tests and cymbals do not sound better when recorded with mics whose response extends to 30kHz and that's precisely why, after 20+ years of testing, there are no mics specifically designed for recording cymbals!!!!
3. You're joking right? If you suddenly had access to a new technology, what would be the very first thing you'd do with it? Wouldn't you test those new technology aspects exhaustively and start with the most likely and common source to expose that technology? So, of course I've actually tried it, countless times over many years and so has pretty much every experienced commercial sound engineer.
[1] Is it REALLY so much more unreasonable to buy a file whose frequency response extends to 45 kHz, "just because you prefer to have something a lot better than the minimum you actually need",
[1a] ... than it is to buy a sports car that can go 120 mpH and accelerate like the wind, or a precision stainless steel ruler that's accurate to 1/64", even though we all know that 1/8" is plenty accurate for that magazine rack you're building? [1b] Have you considered the possibility that some audiophiles simply enjoy knowing that their equipment, and their music, is significantly better than they'll ever need, instead of "just good enough"?
1. Yes, it is unreasonable because it's just a marketing lie that you're getting "something a lot better than the minimum". What you're actually getting in the best case scenario is something that's exactly the same and commonly, something that's actually worse!
1a. Is it unreasonable to buy and pay extra for a sports car that is advertised as a sports car with 120MPH top speed but at best only performs the same as a ford fiesta and at least some of the time can't even keep up with a ford fiesta?
1b. And have you, as a member of the trade, ever considered the possibility that convincing audiophiles they're getting something better than they'll ever need and omitting the fact that they've already got something better than they'll ever need (by falsely characterising it as not good enough or "just good enough") is a profitable marketing tactic?
A lot of the recent discussions have included the claim that "ultrasonic frequencies are so heavily attenuated by air that they never reach the listener in significant amounts".
[1] However, with all the anecdotal claims, I haven't seen much actual DATA, so I thought I'd provide some.
[2] The attenuation, at 30 kHz, under those conditions, is 0.647 dB / meter ..
1. Ideal, two falsehoods/fallacious tactics in one sentence, I'm impressed! Firstly, how come you haven't seen much actual DATA when so much of it has been presented, did you "inadvertently" miss it again? (For example this post #10636). Secondly, the old audiophile marketing tactic of providing "some" actual data but "inadvertently" ignoring the other relevant data and thereby misrepresenting the facts/data! ...
2. Under more realistic conditions (50% humidity, as musical instruments do not cope well with low or high humidity), the high freq absorption is 0.937dB/m which at say 20m is a loss of 18.74dB. However, as stated in the previous point (and in previous posts!), that is not the only relevant data! There is also damping of sound level vs distance, IN ADDITION to purely high freq absorption. At 20m (relative to say 0.5 meters) we loose 32.04dB, so now our 30kHz signal is down by 50.78dB. Another piece of ACTUAL DATA you've ignored (despite the fact it's been posted several times) is that in the case of a cymbal, only about 6% of it's energy is above 20kHz. So, we've got a relatively small amount of signal >20kHz to start with and what's left is going to be attenuated by over 50dB. We should also consider the rising thermal noise of mics and mic-preamps with frequency, which definitely comes into play with signal loss over distance and If we're talking about a live situation, then we should also include the significant damping cause by the audience itself. After all this attenuation, there's simply nothing left to record above the noise floor, let alone hear! So yet again, round and round in circles we go, caused by you yet again (inadvertently?) misrepresenting the facts. Are you ever going to stop insulting this forum?
This suggests several things.......
1) There in fact is significant attenuation of even audible high frequencies at the distances you might typically encounter in a living room or concert hall
2) Attenuation of even relatively high ultrasonic frequencies is significant - BUT FAR FROM ABSOLUTE - at typical listening distances
3) Attenuation of even high ultrasonic frequencies at one or two meters (at the distance of a "close mic", for example, on a drum set) is relatively minor
1. True.
2. True but only if you (inadvertently?) omit the relevant, uncontested facts and (inadvertently?) ignore some of the laws of physics!
3. True but I ask you again (because you refuse to answer) do you or an audience ever sit with your ears one inch away from the snare drum during a performance or a couple of feet away from the cymbals? Have you ever tried it? Have you any idea what it sounds like? Do you even have any idea how preposterous it would be?
here is where I stand right now: + we shouldn't reject audibility above 20khz as we have some kids who notice 22khz or even higher just fine and that alone disproves the notion that nobody is hearing ultrasounds.
I'm not disputing that given the right conditions 22kHz is audible, in fact quite the opposite, I've stated that given the right conditions, everything is audible, even much higher than 22kHz! The relevant question is: Do those conditions ever exist in the recording and reproduction chains of commercial audio (or live performances) at any reasonable listening level? Firstly of course, no one ever makes commercial audio recording of only a 22kHz tone. >20kHz content (when it does exist) is ONLY the result of higher order harmonics and is tiny in amplitude relative to the audible band. Even if it were possible to hear 22kHz at a level of say only 100dB, in commercial audio recordings that means the peak level (in the audible band) would have to be at least 130dB and typically, more than 140dB. If instead of 22kHz we were talking about only say a 15kHz signal, it's extremely unlikely that at >40dB below the (more audible band) content it could be "heard" in a commercial audio mix. So, what's the implication of the claim, that our ears perform better at 22kHz than at 15kHz? Admittedly there's essentially (AFAIK) no research in this area, a fact which is misrepresented/abused by those with an agenda. The reason there's no research is that it is too dangerous to carry out such research, peak levels of 130dB and above will cause pain and damage, >140dB will cause almost instantaneous damage. In other words, the reason the research has not been carried out is itself evidence/proof that it's inaudible.
What's disingenuous is that those supporting the claims actually seem to have some understanding of the facts but just abuse them depending on what they're arguing about at the time. For example @Phronesis stated "I think it's important to use a pure tone, otherwise harmonics can confuse us about what's going on." - As seems to be so often the case in these disputes, a true argument that's used to support one specific point is in fact self-contradictory and an argument against the claim itself. While Phronesis' statement is true, in practise it supports the argument AGAINST the claim because very high/ultrasonic frequencies in commercial audio recordings ONLY exist as harmonics and high order harmonics to boot! These tactics have gone way beyond tiresome!!
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