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Is it possible for frequencies we can't hear to affect frequencies
dannytran1191
post Aug 20 2013, 10:52
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I recently read a very detailed explanation of why 24-bit/192kHz lossless music is useless, even harmful. The link is here: https://www.xiph.org/~xiphmont/demo/neil-young.html. Then, I read another post on head-fi.org about why it's beneficial. I'll post it below.

"Going to clarify what I stated earlier:



Bit Depth refers to the number of bits you have to capture audio. The easiest way to envision this is as a series of levels, that audio energy can be sliced at any given moment in time. With 16 bit audio, there are 65,536 possible levels. With every bit of greater resolution, the number of levels double. By the time we get to 24 bit, we actually have 16,777,216 levels. Remember we are talking about a slice of audio frozen in a single moment of time.

Now lets add our friend Time into the picture. That's where we get into the Sample Rate.

The sample rate is the number of times your audio is measured (sampled) per second. So at the red book standard for CDs, the sample rate is 44.1 kHz or 44,100 slices every second. So what is the 96khz sample rate? You guessed it. It's 96,000 slices of audio sampled each second.



Space required for of stereo digital audio

Bit Depth Sample Rate Bit Rate File Size of one stereo minute File size of a three minute song

16 44,100 1.35 Mbit/sec 10.1 megabytes 30.3 megabytes

16 48,000 1.46 Mbit/sec 11.0 megabytes 33 megabytes

24 96,000 4.39 Mbit/sec 33.0 megabytes 99 megabytes

mp3 file 128 k/bit rate 0.13 Mbit/Sec 0.94 megabytes 2.82 megabytes

So you see how recording at 24/96 more than triples your file size. Lets take a 3 minute multi-track song and add up the numbers. Just to put the above into greater relief, I included the standard MP3 file's spec.



Hard disk requirements for a multi-track 3 minute song

Bit depth/sample rate number of mono tracks size per mono track size per song songs per 20 gigabyte hard disk songs per 200 gigabyte hard disk

16/44.1 8 15.1 megs 121 megs 164 1640

16/48 8 16.5megs 132 megs 150 1500

24/96 8 49.5 megs 396 megs 50 500

16/44.1 16 15.1 megs 242megs 82 820

16/48 16 16.5 megs 264 megs 74 740

24/96 16 49.5 megs 792 megs 24 240



you should be noting two things now:

1. Recording at 24/96 yields greatly increased audio resolution-over 250 times that at 16/44.1

2. Recording at 24/96 takes up roughly 3 1/4 times the space than recording at 16/44.1



Now lets get to the subjective side of how music sounds at these different bit depths and sample rates. No one can really quantify how much better a song is going to sound recorded at 24/96. Just because a 24/96 file has 250 times the audio resolution does not mean it will sound 250 times better; it won't even sound twice the quality. In truth, your non-musically inclined friends may not even notice the difference. You probably will, but don't expect anything daramatic. Can you hear the difference between an MP3 and a wave file? If so, you will probably hear the difference between different sample rates. For example, the difference between 22.05 kHz and 44.1 kHz is very clear to most music lovers. A trained ear can tell the difference between 32khz and 44.1. But when 44.1 and 96kHz are compared it gets real subjective. But lets try to be a little objective here.



Lets talk about sample rate and the Nyquist Theory. This theory is that the actual upper threshold of a piece of digital audio will top out at half the sample rate. So if you are recording at 44.1, the highest frequencies generated will be around 22kHz. That is 2khz higher than the typical human with excellent hearing can hear. Now we get into the real voodoo. Audiophiles have claimed since the beginning of digital audio that vinyl records on an analog system sound better than digital audio. Indeed, you can find evidence that analog recording and playback equipment can be measured up to 50khz, over twice our threshold of hearing. Here's the great mystery. The theory is that audio energy, even though we don't hear it, exists as has an effect on the lower frequencies we do hear. Back to the Nyquist theory, a 96khz sample rate will translate into potential audio output at 48khz, not too far from the finest analog sound reproduction. This leads one to surmise that the same principle is at work. The audio is improved in a threshold we cannot perceive and it makes what we can hear "better". Like I said, it's voodoo."


Pay close attention to that last paragraph. Is it really possible for frequencies we cannot hear to affect what we do hear? Please include evidence in your responses if you can.
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ktf
post Aug 20 2013, 12:01
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If a system is linear and time-invariant (LTI), it is mathematically proven that frequencies not in the input cannot be in the output. If any system used in the reproduction of your audio (amplifier, speaker, the air between the speaker and your ear) is not LTI, it is very well possible that frequencies above 20kHz fold down into the 20Hz-20kHz band. Whether or not this is audible depends on a lot of things.


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db1989
post Aug 20 2013, 12:07
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And it would not be a desirable feature in any case.

From the perspective of proper reproduction, I mean: perhaps some people might have grown to like the sound of aliased frequencies, but that would be something completely different, and if it does lead to unduly favourable impressions of high-res audio, that would actually be undercutting their argument (again).
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Nessuno
post Aug 20 2013, 12:09
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QUOTE (dannytran1191 @ Aug 20 2013, 11:52) *
Is it really possible for frequencies we cannot hear to affect what we do hear? Please include evidence in your responses if you can.


Let's take a naive approach to the matter: it has been demonstrated that even the finest (as to say, youngest) human auditory system is definitely not sensible to single tones above 22kHz. So if this phenomenon were true, it must happen outside of our ears/brain: a "modulation" of audible tones by ultrasonic frequency while travelling by mean of air molecules. Maybe this could happen, but its effects in audible range would be, on turn, perfectly stored and reproduced by a sampling rate of 44.1kHz as per Shannon theorem.

Edit, after reading db1989's reply: yes, of course I was speaking about ultrasonics generated by the real source, not by the playing system.

This post has been edited by Nessuno: Aug 20 2013, 12:25


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Rotareneg
post Aug 20 2013, 17:00
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Yes, you can get audible sound from ultrasound: http://en.wikipedia.org/wiki/Sound_from_ultrasound , but that is an unusual phenomenon which happens at very high sound levels (100+ dBSPL.) And, like Nessuno says, the resulting audible-to-the-ear sound would still be accurately recorded at normal sampling rates.

I suppose it's possible there might be other non-linear effects inside the recording device itself that might result in audible differences between a conventional microphone and the squishy wet flesh microphone in your ear, but again that would appear to be limited to sounds with a very intense ultrasonic component.
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drewfx
post Aug 20 2013, 17:10
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QUOTE
The theory is that audio energy, even though we don't hear it, exists as has an effect on the lower frequencies we do hear. Back to the Nyquist theory, a 96khz sample rate will translate into potential audio output at 48khz, not too far from the finest analog sound reproduction. This leads one to surmise that the same principle is at work. The audio is improved in a threshold we cannot perceive and it makes what we can hear "better".


People like to dance around the idea that they can somehow perceive something that they admit they can't perceive.

The thinking is something like, "even though I can't perceive it directly, and if I do a DBT/ABX test I still can't perceive it, maybe I still perceive it even though I don't perceive that I'm perceiving it".
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Arnold B. Kruege...
post Aug 20 2013, 17:14
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QUOTE (dannytran1191 @ Aug 20 2013, 05:52) *
I recently read a very detailed explanation of why 24-bit/192kHz lossless music is useless, even harmful. The link is here: https://www.xiph.org/~xiphmont/demo/neil-young.html.


IOW a credible account of well known data

QUOTE
Now lets get to the subjective side of how music sounds at these different bit depths and sample rates. No one can really quantify how much better a song is going to sound recorded at 24/96.


Actually we can. We already know based on any number of reliable listening tests done by many people under various but well-controlled circumstances, that presuming a reasonably linear playback system, 24/96 adds nothing audible over 16/44. The first reference from xiph.org is a very clear and well documented explanation of the reasons why. I presume you read it. Presenting something that someone made up from head-fi.org as being somehow equally credible suggests severe perceptual problems or a dire lack of appreciation of or familiarity with modern science.

QUOTE
Just because a 24/96 file has 250 times the audio resolution does not mean it will sound 250 times better; it won't even sound twice the quality. In truth, your non-musically inclined friends may not even notice the difference. You probably will, but don't expect anything daramatic.


I call the above argumentation by means of pouring sugar into the reader's ears. The basic message is that philistines like the man on the street can't hear the benefits of high sample rates, but persons of character and taste such as yourself can. People with true character and taste can see that the argument is free of reliable evidence.

QUOTE
For example, the difference between 22.05 kHz and 44.1 kHz is very clear to most music lovers. A trained ear can tell the difference between 32khz and 44.1. But when 44.1 and 96kHz are compared it gets real subjective. But lets try to be a little objective here.


There is nothing subjective about hearing the difference beween music sampled at 44.1 and 96, it is mission impossible (subject to the same assumptions as my comments above).



QUOTE
Lets talk about sample rate and the Nyquist Theory. This theory is that the actual upper threshold of a piece of digital audio will top out at half the sample rate. So if you are recording at 44.1, the highest frequencies generated will be around 22kHz. That is 2khz higher than the typical human with excellent hearing can hear.


I don't know about that. If its loud enough (> 100 dB) I used to be able to hear a very high pitched whistle from a 22 KHz tone. Trouble is, the issue is not hearing pure tones, but rather hearing the action of brick wall filters applied to music. This involves hearing concurrent tones, and that in turn invokes masking. Masking appears to be one of those things that fly over the heads of a lot of people but it is very powerful. Its the reason why we have to struggle so hard to sort out well-made high bitrate lossy coded files from .wav files in DBTs.

Anybody wanna take bets on whether the author of this little ditty from Head-fi has ever had the privelege of trying to do such a DBT?

QUOTE
Now we get into the real voodoo. Audiophiles have claimed since the beginning of digital audio that vinyl records on an analog system sound better than digital audio.


Claims are cheap even free. Reliable evidence costs a little more.

QUOTE
Indeed, you can find evidence that analog recording and playback equipment can be measured up to 50khz, over twice our threshold of hearing.


Actually, its easy to measure anything to 100 KHz with common digital test equipment, and up to 3 MHz or more with analog test equipment.

Now the question of whether you measure anything useful up there is a different question. Fact is that analog tape has built in fairly sharp, nearly brick wall filtering action depending on tape composition, tape speed, head gaps and bias frequency. A modern 15 ips studio machine has a fairly strong brick wall filtering effect that starts around 24 KHz. The Head-Fi writer obviously does not know that.

Now lets talk about high frequency on vinyl. Some people remember that the CD-4 Quadraphonic surround LP format was based on 30 KHz carriers and recording that in theory might have gone up to 45 KHz. From that they extrapolate that it is possible to record music on LPs up to 30 or 45 KHz. Now for the reality check. The first news flash is that the 30 KHz CD4 carrier was a temporary artifact. Play it a few dozen times (sometimes less than a dozen) with even the best magic (Sibata - wear o matic) stylus and there isn't enough of it left to be picked up by a highly sensitive narrowband receiver in the CD4 decoder. Guess what happened to any musically useful sidebands? Long gone or distorted beyond belief.

The reason why is that according to extrapolated data from Shure's recommended cutting velocities for 40 KHz are about 30 dB below what they are at 3 KHz, the point where recorded velocities on a LP starts falling off. Ironically, RIAA preemphasis starts turning up at about the same mid-band frequency, resulting a dramatic loss in LP actual dynamic range above it. And this is one very strong reason why LPs generally sound different than CDs - CDs have no such limitations nor is premphasis necessarily used.

QUOTE
Here's the great mystery. The theory is that audio energy, even though we don't hear it, exists as has an effect on the lower frequencies we do hear. Back to the Nyquist theory, a 96khz sample rate will translate into potential audio output at 48khz, not too far from the finest analog sound reproduction. This leads one to surmise that the same principle is at work. The audio is improved in a threshold we cannot perceive and it makes what we can hear "better". Like I said, it's voodoo."[/b]


Unsupported theories are less than a dime a dozen, and this one has a mountain of experimental data working against it.

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dhromed
post Aug 20 2013, 18:04
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QUOTE (dannytran1191 @ Aug 20 2013, 11:52) *
Pay close attention to that last paragraph. Is it really possible for frequencies we cannot hear to affect what we do hear? Please include evidence in your responses if you can.


Have another read at that neal-young page again, since I don't think you got it all. It should be enough to dispel any idea of truth in the bold text.

Also pay attention to the specific rhetorical style of the bold text: the author is not actually explaining or demonstrating anything. It's just claims, fluffed up and wrapped up in words and numbers that give the appearance of having a point.

If there are specific points in the article you don't understand, feel free to ask or research them a little further.

QUOTE
The theory is that audio energy, even though we don't hear it, exists as has an effect on the lower frequencies we do hear.


It's not a "theory", it's barely worth calling a hypothesis. It's wishful thinking and conjecture based on partial or absent understanding plus overly romantic feelings for music reproduction.

The only effect out-of-band frequencies have on storage and reproduction is when the signal isn't properly lowpassed, and the sample rate is less than twice the highest frequency in the input signal. If you sample a signal at 44100Hz, and that signal has frequencies equal or above 22050Hz, those frequencies will make themselves quite known in the sampled signal in the form of much lower frequencies; the 'alias' of that frequency. It's pretty gross distortion and very much unwanted. A 40000Hz tone in that example would reappear in our sampled audio as a 4100Hz tone, and you really don't want to hear that.
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dhromed
post Aug 20 2013, 18:10
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QUOTE (drewfx @ Aug 20 2013, 18:10) *
The thinking is something like, "even though I can't perceive it directly, and if I do a DBT/ABX test I still can't perceive it, maybe I still perceive it even though I don't perceive that I'm perceiving it".


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mrt.mars
post Aug 20 2013, 21:46
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I propose at looking soundwaves on a more grand scale, earthquakes. No human can "hear" primary or "p" waves, yes? Yet there is a profound organic and inorganic reaction to these, even more than the secondary or "s" wave which can be heard. An MRI machine uses magnetic waves to generate an image by giving organic material an artificially high wavelength. One might think of frequencies out of visible or auditory range as not as useless, but "it is always darkest before the dawn" analogy. Like the resolution and brightness of a display is achieved by getting closer to the holy grail of "absolute black". Just a thought

This post has been edited by mrt.mars: Aug 20 2013, 21:49
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db1989
post Aug 20 2013, 23:47
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QUOTE
Just a thought
And neither a substantiated nor a new one.

Please provide any kind of substantiation whatsoever for the many profound implications you are making, given that they run contrary to the established evidence.

Irrelevant analogies to totally separate phenomena do not support your position, in case there is some confusion: quite the opposite.

On the basis of your two posts here so far, it is clear that you do not understand how the site operates. Please orient yourself with #8 of the terms of service, which you were asked to, and should have, read during registration. We expect you to abide by them by providing evidence for all of your grand statements, rather than deceptive metaphors and appeals to mystery.

This post has been edited by db1989: Aug 20 2013, 23:52
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mrt.mars
post Aug 21 2013, 01:25
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QUOTE (db1989 @ Aug 20 2013, 18:47) *
QUOTE
Just a thought
And neither a substantiated nor a new one.

Please provide any kind of substantiation whatsoever for the many profound implications you are making, given that they run contrary to the established evidence.

Irrelevant analogies to totally separate phenomena do not support your position, in case there is some confusion: quite the opposite.

On the basis of your two posts here so far, it is clear that you do not understand how the site operates. Please orient yourself with #8 of the terms of service, which you were asked to, and should have, read during registration. We expect you to abide by them by providing evidence for all of your grand statements, rather than deceptive metaphors and appeals to mystery.

Sir, I am speaking of the physical, involuntary response induced, or transduced by harmonics. take the scillia in the inner ear. High inaudible harmonics do cause the scillia to "stand-up" as it were. Including The effect of p waves on solids and liquids. It is a proven fact that these harmonics are the chief cause of destruction via the harmonic dissonance. I am not a scientist, just a guy with a curious mind. A thousand pardons! But my 24/192 Ogg conversion was on point though. This is too high brow for me. So I will not be returning here to post anymore. Later.
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db1989
post Aug 21 2013, 01:45
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QUOTE (mrt.mars @ Aug 21 2013, 01:25) *
Sir, I am speaking of the physical, involuntary response induced, or transduced by harmonics. take the scillia in the inner ear. High inaudible harmonics do cause the scillia to "stand-up" as it were.
And has this been proven to be detectable at all? If not, it is, again, irrelevant.

QUOTE
Including The effect of p waves on solids and liquids. It is a proven fact that these harmonics are the chief cause of destruction via the harmonic dissonance.
Again, analogies to other classes of phenomena are not valid and serve more as misdirection than anything else.

QUOTE
But my 24/192 Ogg conversion was on point though.
No, it was another round of evidence-free statements asserting personal perception as fact, and it was deleted as such by some other member(s) of staff.

QUOTE
I am not a scientist, just a guy with a curious mind. A thousand pardons! […] This is too high brow for me. So I will not be returning here to post anymore. Later.
Too high-brow, or just disappointingly unwilling to accept your bold claims on faith? If they were as real as you imply, you would have no problem providing the evidence that our rules clearly require. You cannot come here, make profound statements that use supposedly scientific concepts to disagree with established ideas and thus indicate confidence in your own intellect (read: brow), and then complain that we are too high-brow merely in requiring you to back up what you say! I might reasonably conclude that your ducking out now, still with no substantiation for anything you have said, indicates a tacit admission that no such thing is possible. But no, surely that would be too embarrassingly obvious, and there must be some other, valid reason.

This post has been edited by db1989: Aug 21 2013, 01:46
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JJZolx
post Aug 21 2013, 06:10
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This started as a simple question, and in true HA form (moderators first, by all means) instantly became and anti-audiophool crusade. You roped in one unsuspecting person with this off-topic tangent, then promptly set upon him.

Well done.

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Kohlrabi
post Aug 21 2013, 09:27
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I'm fine with HA being a bastion against pseudo-science, snake-oil and misinformation. One consequence it seems to me is to lock down these threads quickly in the future, to avoid baiting people into posting their ill-founded beliefs. OTHO everyone who has something constructive to say should be allowed to do so, and nonsense should be clearly flagged as such. Someone who posts on an internet forum should be able to withstand some critics. If you don't agree to have an evidence-based discussions you can choose from a plethora of other forums out there where you can engage in a different kind of discussion.


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probedb
post Aug 21 2013, 09:44
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QUOTE (JJZolx @ Aug 21 2013, 06:10) *
This started as a simple question, and in true HA form (moderators first, by all means) instantly became and anti-audiophool crusade. You roped in one unsuspecting person with this off-topic tangent, then promptly set upon him.

Well done.


I'm not sure of the issue? The first post seems to have been discussed fairly, not really a crusade. How did anyone rope anyone into a discussion, the poster decided to post, it's not like a group of people here decide to tell someone to post something which obviously goes against the Ts&Cs of the site so they can pick it apart.
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Wombat
post Aug 21 2013, 10:44
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I have also the feeling there is going on more trolling lately.
It is often very new members asking questions exactly in the way to get several people in here in the need of correcting the obvious wrong reasoning and see what happens.
If that one was trolling it worked out well! Even long term members attack themself smile.gif
I am with kohlrabi. This kind of threads should be locked quickly. There are other forums better suited for such waste.
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dhromed
post Aug 21 2013, 12:01
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QUOTE (JJZolx @ Aug 21 2013, 07:10) *
You roped in one unsuspecting person with this off-topic tangent, then promptly set upon him.

What? Nobody was roped in. The OP asked an honest question and I think was handled well. That mrt.mars confused their random musings for rational thought is not HA's fault.

That said.. can't we just... be nice? Sometimes it's like some of us are in the very top-left corner of the top-left pixel of the Lawful Good quadrant of the RPG Alignment chart. Let's hold the TOS#8 slapping for when a user has clearly embarked on the path of rainbow-powered technology.
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Kohlrabi
post Aug 21 2013, 12:06
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Let's get back on topic. Regarding a discussion of HAs policies concerning these kind of incidents, feel free to start a discussion on the "Side Related Discussion" forum.

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db1989
post Aug 21 2013, 13:46
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QUOTE (JJZolx @ Aug 21 2013, 06:10) *
This started as a simple question, and in true HA form (moderators first, by all means) instantly became and anti-audiophool crusade. You roped in one unsuspecting person with this off-topic tangent, then promptly set upon him.

Well done.

Save your righteous indignation for someone who is gullible enough to believe it.

Nobody was ďroped inĒ to anything. mrt-mars has done nothing but post blatant violations of #8 since they joined, and what, you think that should be allowed to pass? If people canít understand that dumping a load of violations of rules into a thread justifies a rebuttal by a moderator, I donít know what to tell them.

Given how much concern trolling you do about the same rule, maybe you should follow the example of mrt-mars and acknowledge that posting here is not for you. Certainly most of what Iíve seen you do recently is gurning about us having the gall to enforce our rules. If you want to continue whining about how weíre so nasty, for not rolling over and letting people trample all over the cornerstones of the site, get a blog or something.
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