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Topic: Audibility of "typical" Digital Filters in a Hi-Fi Playback  (Read 367772 times) previous topic - next topic
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Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #875
This BS study lacked investigatory drive in my view. It was very passive. It seems that the study was conceived and implemented, full stop. I note that its two main conclusions are expressed vaguely, or even cryptically.

I'd have thought that preliminary informal tests should have been done with subjects with outstanding hearing and listening skills. This presumably would have shown up high yield (revealing) sections. Then a variation could have been done by way of substituting a different loudspeaker system, or even headphones to see whether a difference was still in evidence.


Yes, it was interesting that they didn't break out individual results, or do this sort of pre-testing to identify the best performers.  Then again they only tested 8 subjects!  They acknowledge the preliminary nature of the work in conclusions , referring to it as a 'small pilot study'.  Which is one reason that trumpeting it as a game-changer is a bit premature.

Quote
The way the two "main" conclusions "offered" are expressed is also passive, and not particularly helpful. It is obvious that audible sounds exist that cannot be transparently encoded at 16/44. Some children can hear a loud sine wave at 23kHz and a standard CD cannot render 23kHz at all. Also if a CD is played back with ear-splitting gain, then dither noise may be audible even to middle-aged adults. It is accordingly quite cryptic and unhelpful to offer as a conclusion: "first, there exist audible signals that cannot be encoded transparently by a standard CD".  Perhaps what was meant was "audible signals contained in conventional music recorded with high definition and listened to at a normal listening level".


Indeed that first conclusion--and btw, the two conclusions in the Abstract are *not* the same as the ones in the 'Conclusion' section --  is really rather curious. It was certainly already known that there are audible signals that CD cannot encode transparently.  So why trumpet that as a 'conclusion' here?  This is what some of us here wondered about as soon as we read the abstract, even before the paper was made public.



Quote
In summary,
  • the BS experimental study appears to have been executed in a passive way, not taking advantage of preliminary informal testing to pinpoint what was causing an apparent lack of transparency in the filter emulations (particularly the emulation for a sample rate reduction to 44.1kHz), and
  • the two main conclusions offered are vaguely expressed and unhelpful, and in the case of the second conclusion (about the need for a hi-fidelity reproduction chain) not actually supported by experiment.


But note again, those 'conclusions' are not offered in the actual conclusion section of the paper -- there, there are 5 conclusions that are more specific. If I reviewed this I would have told the authors to bring their Abstract more in line with the Conclusions, or vice-versa.

Quote
CONCLUSIONS
1. FIR filters that emulate downsampling for sam-
ple rates of 44.1 kHz and 48 kHz can have a dele-
terious eff ect on the listening experience in a
wideband playback system.
2. 16-bit quantization with and without RPDF
dither can have a deleterious eff ect on the listen-
ing experience in a wideband playback system.
3. Our fi ndings are consistent with the idea that
filters with long impulse responses blur fine tem-
poral details of signals.
4. Not all pieces of music contain musical features
that demonstrate these losses of transparency.
Possible important features include echoes that
give a sense of the physical space around the
performers.
5. Consideration should be given to the use of psy-
chophysical tests that minimise cognitive load
in studies of this kind.



Quote
Further comments
For someone familiar with MATLAB audio filters, it is a walk in the park to alter the parameters. The BS study could have been so much more. In my opinion, it was a narrowly focussed endeavour, with vaguely expressed conclusions.


It is meant as a riposte to Meyer and Moran 2007 -- the dragon the authors spend much text trying to slay in the Introduction.  There is a 'history' there.


Quote
Whilst it is true (well established in fact) that truncation to 16-bits has been found to be inadequate, this comment in my opinion is passive, and misdirected. Real life CDs are not produced from undithered low-noise truncations to 16 bits.

[Hypothetical sentences:]  We note that in practice standard CDs are not produced with quantization alone (that is to say discarding all bits beyond the 16th by way of truncation) but with dither. Dither allows bits beyond the 16th to be reflected in the audible signal, despite the signal being distributed to the consumer in a 16-bit format. We would stress that the test conditions that involved quantization without accompanying dither were merely a "probe" to serve as a reference point: there is no suggestion that standard CDs are produced in this way.

Alas, no such qualifying sentences appear in this part of the report. I think it is this tenth page of the report that will be fodder for high definition proponents not averse to letting technical accuracy get in the way of condemning the standard CD format for its "insufficient" 16 bits; or simply not understanding the benefits of dither.


More odd is that IIRC Stuart himself acknowledged much the same point in his older Coding for High Resolution Audio' review paper. And of course the promotional material AJinFla has quoted multiple times show that Meridian has previously touted the 'transparency' of TBDF dither.

 

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #876
Is anybody denying that here? On the contrary, everyone here noticed that years ago, and pointed out the stupidity of the endeavour back then already. Nothing has changed since then.

They must be denying it if they think it is a stupid thing.  More consumer choice is never a stupid thing.  And getting the original instead of the converted one by who knows what, is not a stupid thing.

Quote
Are they? It's not unthinkable or impossible for a company to use or create an audio container with DRM and special hardware or software requirements.

Complain when that happens.  Right now, the miracle has happened.  We are getting high-resolution masters with absolutely no copy protection. 

Quote
Monty has pointed out that in practice hi-res playback might have a lower audio fidelity due to distortions coming from high-frequency content.

I have known Monty more than many of you.  He is a super smart guy but has little expertise in this area.  I have debated his write-up with him on WBF Forum and have shown the many flaws in his blog on AVS Forum.  He has improved his write-up some but at the end of the day, it is yet another person writing about a field that is not his specialty.  He doesn't understand the business side of this field, nor does he have electrical engineering experience to understand the hardware side.  You want to the right version of that, read Stuart's JAES paper, coding for high-resolution audio.  Anything beyond that which Monty says is yet another online blogger making arguments with no personal data or professional experience.

As to his theory of IM distortion, it is just that: some theory.  Arny posts test files on AVS to bring out such distortion and I and a number of other people reported no problems at all.  And at any rate, as I mentioned, if you think there is a problem there, you can always filter the files yourself.  You can't do the reverse.

Quote
People like you always know that the "best quality" is up from whatever is the current standard. That's the oldschool audiophile delusion.

What do you mean people like me?  I am an objectivist, engineer and professional who has worked in this field for many years.  I am not some subjectivist you would throw that line at and sit back. 

You are wrong and that can be trivially shown. There are many high-resolution stereo masters that are distributed prior to loudness compression of CD/MP3.  There is nothing delusional about their improved fidelity.  You speak from point of view of forum facts, not real life facts.

Even if they are identical mastering, there is no way you can tell me someone is doing me a favor by converting to 16/44.  I can do that myself and don't need someone whose expertise is to create music to know the TPDF dither from a hole in the wall.

Quote
5. By a miracle, the music labels have decided to license their studio masters to us.  You don't see that in movies, do you?  This is a gift to be embraced.
I still wonder why you assume hi-res masters to be inherently superior to CD masters. What prohibits engineers from fucking up those, too? They managed to make 16/44 sound like shit, it's just as easily possible with 24/96. Audio technology is not the problem, it's human error.

I assume it because I personally know the people who create them.  And the founder of the biggest distributor of such (HD tracks).  You don't have that kind of real life data and relationship, right?  So what you hypothesize is just FUD and random arguments thrown out there.  What if I got a steak house and they feed me hamburger they bought from Burger King.  Yes, it could happen but come back when you know it has.

The market for high resolution audio has been established.  Content distributors know that people will immediately run spectrum analyzer and compare CD to high-res versions.  QC has improved substantially and I expect over time for high resolution audio to almost always being the same or better fidelity than the CD.  The notion that it can be worse is absurd.

Quote
Lossy delivery can be acceptable with proper mastering. The CD releases you get today are (depending on genre) hardly more than 12bit/32khz anyway.

Lossy if it becomes the only copy available, is anything but acceptable.  I am not going to endorse going backward in fidelity in the name of technological advancement.  If you want to go there, do but don't tell me it should be acceptable to me.  And the other statement is just absurd and is never backed by any references or real data.  But maybe you surprise us and give us such and not come across as copious producer of FUD.

Quote
See above. The conjecture that audio engineers will magically improve their craft just due to the existence of a hi-res audio format is absurd. Again, it is already possible to produce proper releases on CD today (which has been demonstrated in the classical and soundtrack genres), it's just not done.

The don't need to improve their craft because you have some made up fantasy argument on forums that effective resolution of music today is 12 bits/32 Khz.  Do you even know how loud the channel noise at 12 bits is?  That is signal to noise ratio of cassette tape.

So , no magical improvement is required.  All that needs to happen, which fortunately already has, is to get the upstream bits prior to CD/MP3 mastering.  I gave evidence of this earlier:
=====
See this from many such examples, for one of the award winning mastering engineers, Doug Sax: http://mixonline.com/news/profiles/masteri...h.cHY5BQ9r.dpuf

When he was invited to sit on Ludwig’s Platinum Mastering Panel this year, Doug Sax suggested they discuss mastering for multiple formats. “Ten years ago, you made a CD master and you were done,” Sax says. “Now you do a CD master, a master for iTunes, a high-resolution master for HDtracks, and a cutting master for vinyl.”
=====

See the separate mastering for HD Tracks?  What we want is happening. 

Quote
[audiophile gibberish]
Get lost already. Nobody gains any insight from reading your FUD nonsense and propaganda.

As if your reply to me had an ounce of insight or data?  All you spread is FUD and turn around and say that to me? 

But sure.  I will be leaving shortly as I have never seen so many unprofessional posters in any audio forum.
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #877
Don't go responding to this post because per above, you don't matter.  AJ doesn't matter.  Krab doesn't matter.  None of you do.  Get a sense of reality, conduct yourself more professionally and join the audiophiles elsewhere in increases the choice of formats we have.  Heaven knows I am getting bored interacting with you all.


And when you are king.... oh wait, in your mind, you already *are*. 

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #878
You are wrong and that can be trivially shown. There are many high-resolution stereo masters that are distributed prior to loudness compression of CD/MP3. There is nothing delusional about their improved fidelity. You speak from point of view of forum facts, not real life facts.
You're comparing different masters.

That is signal to noise ratio of cassette tape.
Exactly. Again, it's not the technology but the actual delivered recording. Numbers don't mean anything if they are not used. That is the point which we try to hammer in your head for days now. Engineers are not using CDs to their full theoretical capacity, so why on earth do you assume giving them even more bits will help with anything?

See the separate mastering for HD Tracks?  What we want is happening.
There is no need for separate mastering. All you need to do to create a CD master from a hi-res master is to decimate to 16bits using proper noise shaped dithering and resample to 44.1kHz. Anybody who's doing it differently doesn't have a clue what he's doing.

As if your reply to me had an ounce of insight or data?
I have two CDs here. One is the Gladiator soundtrack. The other is Californication. It's trivially obvious to people who know the latter CD that it suffers from distortion and extreme dynamic range compression, so that the end-result is hardly bearable. The former CD is intended as a high-quality soundtrack, and the production shows. Now comes the clue for you, which you have to try to sink into your mind once and for all. Both releases are delivered via redbook audio CD. That means they use the same digital audio technology. Hence any difference in dynamics and distortions are a product of the production. There is simply no other possibility left. That means any distortions and DRC are due to the production quality and decisions and not inherent to the delivery format. q.e.d.
It's only audiophile if it's inconvenient.

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #879
Quote
Monty has pointed out that in practice hi-res playback might have a lower audio fidelity due to distortions coming from high-frequency content.

I have known Monty more than many of you.  He is a super smart guy but has little expertise in this area.  I have debated his write-up with him on WBF Forum and have shown the many flaws in his blog on AVS Forum.  He has improved his write-up some but at the end of the day, it is yet another person writing about a field that is not his specialty.  He doesn't understand the business side of this field, nor does he have electrical engineering experience to understand the hardware side.  You want to the right version of that, read Stuart's JAES paper, coding for high-resolution audio.  Anything beyond that which Monty says is yet another online blogger making arguments with no personal data or professional experience.


LOL!  You're always *what's best* Amir.  I'm sure your parents told you that all the time.  So we'll tell you too, if it keep s you calm.

But Monty is hardly the only one to point out that hi-rez could produce distortions in some setups.  Indeed, SACD players have built-in lowpass output filters after the DAC (at 50 or 100kHz) to try to ameliorate that.



Quote
Quote
I still wonder why you assume hi-res masters to be inherently superior to CD masters. What prohibits engineers from fucking up those, too? They managed to make 16/44 sound like shit, it's just as easily possible with 24/96. Audio technology is not the problem, it's human error.

I assume it because I personally know the people who create them.  And the founder of the biggest distributor of such (HD tracks).  You don't have that kind of real life data and relationship, right?  So what you hypothesize is just FUD and random arguments thrown out there.  What if I got a steak house and they feed me hamburger they bought from Burger King.  Yes, it could happen but come back when you know it has.



Actually HD tracks has been dunned for offering tracks that aren't really 'HD'.  Heck, you've  seen Bruce from Puget Sounds apologize for this on your own forum!  And of courss DVDA and SACD releases *also* have been revealed as not necessarily being 'hi rez'.  But 'it's just business' right?

Amir, the real 'good fight'  isn't for 'high res'  or 'consumer choice' of formats.  You know that.  The good fight would be the one for *high quality mastering*.  And then *promotion of better acoustics  at home*.

Stop playing the clown for the 'high  res' faction in industry.  Fight the good fight.

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #880
I will be leaving shortly as I have never seen so many unprofessional posters in any audio forum.

Bye. Give Dunning-Kruger my regards.
"I hear it when I see it."

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #881
See the separate mastering for HD Tracks?  What we want is happening.
There is no need for separate mastering. All you need to do to cerate a CD master from a hi-res master is to decimate to 16bits using proper noise shaped dithering and resample to 44.1kHz. Anybody who's doing it differently doesn't have a clue what he's doing.

amirm's argument is that you should increase bits and sampling rate so high, such that it doesn't matter anymore what the clueless person mastering the music is doing.

What he doesn't seem to get in his head is that it's the same person that is responsible for the bad sound quality.
Also, as soon as hi-res slowly becomes the "norm", the bad sound quality will shift from CD audio to hi-res.
"I hear it when I see it."

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #882
Don't go responding to this post because per above, you don't matter.  AJ doesn't matter.  Krab doesn't matter.  None of you do.  Get a sense of reality, conduct yourself more professionally and join the audiophiles elsewhere in increases the choice of formats we have.  Heaven knows I am getting bored interacting with you all.


And when you are king.... oh wait, in your mind, you already *are*. 
In the land of the blind...

I have known Monty more than many of you.  He is a super smart guy but has little expertise in this area.  I have debated his write-up with him on WBF Forum and have shown the many flaws in his blog on AVS Forum.  He has improved his write-up some but at the end of the day, it is yet another person writing about a field that is not his specialty.  He doesn't understand the business side of this field, nor does he have electrical engineering experience to understand the hardware side.  You want to the right version of that, read Stuart's JAES paper, coding for high-resolution audio.  Anything beyond that which Monty says is yet another online blogger making arguments with no personal data or professional experience.
Did you really just say the creator of Ogg and Vorbis has "little expertise" in (digital) audio, and "no professional experience"? That is beyond ridiculous. And, fun fact for you, the "business side" is completely unimportant in technical and scientific arguments. But I guess that was just another weak attempt at trolling, like your whole paragraph.
It's only audiophile if it's inconvenient.

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #883
I have known Monty more than many of you.  He is a super smart guy but has little expertise in this area.  I have debated his write-up with him on WBF Forum and have shown the many flaws in his blog on AVS Forum.  He has improved his write-up some but at the end of the day, it is yet another person writing about a field that is not his specialty.

Ok, we are now officially in the Twilight Zone. That coming from Amir, who on a public forum admitted this::
Quote
Originally Posted by amirm

If what I present doesn't meet some high bar, so be it....
The comparison I performed was using a Mark Levinson No360S against the on-board DACs in five to six DVD-A and SACD players, all playing the same time sync'ed CD. In other words, I would listen to the analog output of the player while its digital output would feed the ML DAC. All front panel lights were turned off in addition to video circuits (yes, all of that made a difference in fidelity).
The two sources were fed to the dual inputs of a Stax "earspeaker" electrostatic headphone amp. If you are not familiar with Stax, you can read learn more about them here: http://www.stax.co.jp/Export/ExportProducts.html. I have three of their units and results are consistent across the board although the highest end unit does make the job a bit easier. Using headphones allowed me to completely eliminate the room and take advantage of the amazing transparency of these headphones to listen for the slightest differences. To latter point, I would often listen to material at levels well above what I would use for listening to music, allowing me to hear detail that would otherwise be lost.
I then picked material that made it easier to detect differences between DACs. I am not going to disclose what constitutes such content. Without such material, the job can range from difficult to impossible. One has to know what could be damaged by a DAC and then use music that has such content. To give you an example, when you compress music, it is the transients that suffer. So something like guitar music is much more revealing than say, violin as the latter is much more harmonic than the sharp impulses of a guitar. Voices play the same role. None of these are useful for testing DACs though so don’t use that as a hint to the question posed . You can’t test the cornering of a car if you just drive it straight….
The comparison was then conducted without knowing which input is which, sitting in front of the headphone amp and toggling back and forth. When necessary, I would go back and re-listen. Once I found which one sounded worse, I would then repeat the exercise by randomizing the inputs and seeing if I could still identify which one was worse. My success rate was 100% in the second test (i.e. could always verify that the first result was not by chance). This testing was repeated a number of times comparing the different sources against each other and the ML.
I did not level match anything. However, once I found one source was worse than the other, I would then turn up the volume to counter any effect there. Indeed, doing so would close the gap some but it never changed the outcome. Note that the elevated level clearly made that source sound louder than the other. So the advantage was put on the losing side.
The results above were later objectively shown to be backed by some science in Stereophile magazine.

Rank amateur, that Monty. 

He doesn't understand the business side of this field

That might be the truest statement you have ever uttered.
Quote
But How Does it Sound - By Amir Majidimehr
In comparison testing I have done, switching amplifiers using the classic class D configuration always sport incredible low frequency control and power. They beat out linear class AB amplifiers almost regardless of price. What they give up though is high frequency fidelity which I find somewhat harsh. The distortion is highly non-linear and challenging to spot but it is there. The Mark Levinson No 53 is the first switching amplifier I have heard which does not have this compromise. Its bass is amazingly authoritative: tight and powerful. Yet the rest of the response is absolutely neutral and pleasant.
If you have not heard these unique $50k amplifiers, I highly encourage you to come into our showroom for a listen. We have a pair on hand driving our Revel speakers. I am confident that they will improve the sound of your current speakers given the ease with which they can drive any load regardless of how difficult they might be (and many high-end speakers are difficult to drive). We are happy to let you evaluate them with your own system to see the benefits of this technology.  Hearing this amplifier was an eye-opener for me.  I think it will be for you too.

I find it quite refreshing that you have admitted why you are so enamored with this "Hi-Re$" BS paper Amir.
It's understanding the business side of this field....ya understand. 

cheers,

AJ
Loudspeaker manufacturer

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #884
Indeed that first conclusion--and btw, the two conclusions in the Abstract are *not* the same as the ones in the 'Conclusion' section --  is really rather curious. It was certainly already known that there are audible signals that CD cannot encode transparently.  So why trumpet that as a 'conclusion' here?  This is what some of us here wondered about as soon as we read the abstract, even before the paper was made public.

...

But note again, those 'conclusions' are not offered in the actual conclusion section of the paper -- there, there are 5 conclusions that are more specific. If I reviewed this I would have told the authors to bring their Abstract more in line with the Conclusions, or vice-versa.

Indeed yes. There is quite a disconnect. Perhaps the peer reviewers didn't read to the end of the paper. (!)

I'll quote the text in the form you provided it, and add in some comments though I think others may already have made some similar comments in this thread:

Quote
CONCLUSIONS
1. FIR filters that emulate downsampling for sam-
ple rates of 44.1 kHz and 48 kHz can have a dele-
terious effect on the listening experience in a
wideband playback system. [This is a bit of a leap. It is one thing to have established that a difference was correctly identified some 60% of the time. It is another to accept subjective remarks made by one or more of the 8 test subjects that the effect was of a degree and nature to be fairly described as having a "deleterious effect on the listening experience". The report provides no detail on how many of the eight test subjects made negative comments, and whether they were test subjects with high scores.]

2. 16-bit quantization with and without RPDF
dither can have a deleterious effect on the listen-
ing experience in a wideband playback system. [Again, "deleterious effect on the listening experience" may be too strong a phrase. "From time to time perceptible effect, that some listeners may describe as deleterious to their listening experience" might have been more appropriate.]

3. Our findings are consistent with the idea that
filters with long impulse responses blur fine tem-
poral details of signals. [The idea is diminished in persuasiveness given that the filtering was of ultrasonic frequencies using linear phase.]

4. Not all pieces of music contain musical features
that demonstrate these losses of transparency.
Possible important features include echoes that
give a sense of the physical space around the
performers. [It might have assisted to try a less aggressive MATLAB filter, and if results were still audible, look for other possible explanations, e.g. some instability in the tweeters triggered by high frequency content. On the other hand, if this was intended very much as a narrow, pilot study, the limited rather passive approach taken is more understandable; and the paper should not spoken of as a "sea change", but rather as "raising questions for further study".]

5. Consideration should be given to the use of psy-
chophysical tests that minimise cognitive load
in studies of this kind. [Certainly it could help if subjects could control which parts of a musical passage (or “section”) they listened to, just as is done routinely by some members of this forum when using foobar and its ABX plug-in! This begs the question why distinguishable passages have not been identified in the past in this forum when applying a filter for a 44.1kHz, or even 48kHz sample rate, for members with a "wideband playback system" (whatever that is intended to mean exactly, in the context of the BS paper).]

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #885
"wideband playback system" (whatever that is intended to mean exactly, in the context of the BS paper).

[a href="https://www.meridian-audio.com/collection/loudspeakers/" rel="nofollow"]https://www.meridian-audio.com/collection/loudspeakers/[/a]
"I hear it when I see it."

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #886
Indeed that first conclusion--and btw, the two conclusions in the Abstract are *not* the same as the ones in the 'Conclusion' section --  is really rather curious. It was certainly already known that there are audible signals that CD cannot encode transparently.  So why trumpet that as a 'conclusion' here?

That's easy to explain: the peer reviewers never even saw the abstracts' two "offered conclusions" because it was written (or modified) after the fact! They thought they were reviewing a paper about how filters can sometimes alter the sound, hence the paper's title, rather than an attack against 44.1 transparency in some situations followed by an immediate, shameless plug for the authors' "truly high fidelity speakers, which are of course necessary to discern such differences", not that any actual evidence to support this second conclusion was presented by way of testing if lesser speakers/gear would fail to show audible distinctions.

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #887
the peer reviewers never even saw the abstracts' two "offered conclusions" because it was written (or modified) after the fact!

That's a pretty bold claim to be making without offering any proof.

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #888
... I still wonder why you assume hi-res masters to be inherently superior to CD masters. What prohibits engineers from fucking up those, too? They managed to make 16/44 sound like shit, it's just as easily possible with 24/96. Audio technology is not the problem, it's human error. ...


No, it's not human error. They do it deliberately and with full knowledge of what they are doing.
Regards,
   Don Hills
"People hear what they see." - Doris Day

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #889
No, it's not human error. They do it deliberately and with full knowledge of what they are doing. sad.gif

There is no rule stipulating that all human errors must be unintentional.

The sound quality deficiencies  of contemporary CD recordings are due to human error (intention or ignorance) and have nothing to do with the technological means available.


Furthermore, what constitutes an error often qualifies as a subjective matter, this situation being very much the case.

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #890
the peer reviewers never even saw the abstracts' two "offered conclusions" because it was written (or modified) after the fact!

That's a pretty bold claim to be making without offering any proof.


Especially as the usual procedure in scientific conferences I've attended, is to submit the abstract *first*.  That's what gets you in the door, and if it's interesting/appropriate enough, you get to present a poster.  If the abstract is considered especially interesting, you get asked to give a spoken presentation, which could become or be accompanied by a 'conference paper'.

So I would consider mzil's theory to be highly speculative. 

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #891
the peer reviewers never even saw the abstracts' two "offered conclusions" because it was written (or modified) after the fact!
That's a pretty bold claim to be making without offering any proof.

  Allowing an original author to slightly modify the wording of a paper's descriptive blurb,  without any change to the actual contents of the paper itself (and without having to resubmit it to a new peer review just because of such a slight modification to the blurb), doesn't seem hard for me to believe at all.

It is speculation, admittedly, sorry if my wording didn't make that clear. I should have written: "That's easy to explain There's an easy way to explain that: the peer reviewers never even saw the abstracts' two "offered conclusions" because it was written (or modified) after the fact!"


Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #893
I've made a short audio file with 4 different dither formats to illustrate the differences.
The source is a 1kHz sine fading from -80dBFS to -160dBFS during 8 seconds. The 4 dither versions are:
1) 24-bit TPDF dither
2) 16-bit TPDF dither
3) 16-bit RPDF dither
4) 16-bit truncated

60dB gain was applied to make the result easier to hear at normal playback levels.
Monitor gain has to be reduced by 60 dB to get the original level back.

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #894
I've made a short audio file with 4 different dither formats to illustrate the differences.
The source is a 1kHz sine fading from -80dBFS to -160dBFS during 8 seconds. The 4 dither versions are:
1) 24-bit TPDF dither
2) 16-bit TPDF dither
3) 16-bit RPDF dither
4) 16-bit truncated

60dB gain was applied to make the result easier to hear at normal playback levels.
Monitor gain has to be reduced by 60 dB to get the original level back.

How did you apply gain? This alone may add own dither or noise. I suggest shifting it by 10 bit.
Is troll-adiposity coming from feederism?
With 24bit music you can listen to silence much louder!

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #895
How did you apply gain? This alone may add own dither or noise. I suggest shifting it by 10 bit.
No dither was added, as can be seen from the last seconds. It is just an illustration of the visible and audible effect of various dithers. In the RPDF version the noise modulation is audible and the waveform shows the non-linear behavior at the end.

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #896
I've made a short audio file with 4 different dither formats to illustrate the differences.
The source is a 1kHz sine fading from -80dBFS to -160dBFS during 8 seconds. The 4 dither versions are:
1) 24-bit TPDF dither
2) 16-bit TPDF dither
3) 16-bit RPDF dither
4) 16-bit truncated

60dB gain was applied to make the result easier to hear at normal playback levels.
Monitor gain has to be reduced by 60 dB to get the original level back.

Thanks for this. Nice and obvious effects.*

__________

*Spoiler (click to show/hide)

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #897
Thanks for this. Nice and obvious effects.*
Please note that "obvious" and "audibility" are related to playback levels. I wanted to illustrate that audibility of RPDF dither depends on the input signal, which makes predictions based on static measurements (as done in the paper) unreliable IMHO.

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #898
The submission process for the 137th AES convention is still publicly available on line...
http://www.aes.org/events/137/authors/137thCallForPapers.pdf

Note the different categories, timescales, and the strong indication that the paper should not exceed 10 pages.

The text at the very top of the paper under discussion matches category 2.
The text at the very top of the other Bob Stuart paper in the same session matches category 1.

The paper under discussion is 12 pages long (though before the header was added, it would have been 10 pages + references and appendix. I don't know if that would have helped or not.)

The abstract had to be delivered two months before the full paper.

Cheers,
David.

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #899
As to his theory of IM distortion, it is just that: some theory.
That's a surprising statement in this context!

IM distortion from ultrasonic signals, measurable in most hi-fi speakers on the planet, and laughably easy to hear with various signals, is just some theory? Yet the audibility of ultrasonic ringing, suggested but not proven as the reason a filtered signal could be picked out 10% better than random choice in one study, is the important thing?


I would suggest that you can either pick evidence to suit your claims while ignoring evidence that does not, or complain that people aren't being objective. But you can't get away with doing both. In the same thread.


It's really disappointing, because it looked like you wanted to explore all avenues and possibilities when you started posting, but it seems that you weigh evidence by how much it supports your pre-decided conclusions, rather than by any objective criteria.

Cheers,
David.