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Topic: Audibility of "typical" Digital Filters in a Hi-Fi Playback  (Read 331515 times) previous topic - next topic
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Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #1000 –
Quote from: amirm on
David, do you approve of these posts?
HA is a reactively moderated forum. I am neither moderator nor deity. I don't need to approve anything.

However, I fear your question and my response are both off topic.

Cheers,
David.

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

Reply #1001 –
Quote from: 2Bdecided on
Quote from: amirm on
Quote from: Arnold B. Krueger on
Lets say that they wanted to actually document the processing that they did. They would give us the Matlab code?

There is no code.

There would be. Even if you drive it through the GUI, it will generate an equivalent MATLAB command line which calls MATLAB functions which in turn generate filter coefficients.

That's not code.  One line invocation of the filter subroutine in Matlab is not code.  The filter response and all the parameters are given.  And the tool used to generate the filter, Matlab filter GUI, specified.  In addition the response of the filter is graphed.  Anyone who knows how to use matlab can recreate the same.  People who can't, need not apply.
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

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

Reply #1002 –
Quote from: 2Bdecided on
Quote from: amirm on
David, do you approve of these posts?
HA is a reactively moderated forum. I am neither moderator nor deity. I don't need to approve anything.

However, I fear your question and my response are both off topic.

Cheers,
David.

I assumed it was not the last go around when you comment thusly:

Quote from: 2Bdecided on
Interesting that you think technical facts "pollute" a technical discussion.


Does his post constitute polluting a technical discussion?  You objected to my remark and I am trying to get calibrated on what you mean.
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

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

Reply #1003 –
Quote from: ajinfla on
Quote from: amirm on
Quote from: Arnold B. Krueger on
Lets say that they wanted to actually document the processing that they did. They would give us the Matlab code?
There is no code.
There's no spoon either.  Guess repeatability wasn't one of the goals of the BS paper. Just a farce to prime the pump for MQA eh?  cheers,  AJ


But isn't reproducibility one of the main principles of the scientific method? Oh, it is:

http://en.wikipedia.org/wiki/Reproducibility

The AES gives awards to such papers?

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

Reply #1004 –
Quote from: mzil on
Quote from: ajinfla on
Quote from: amirm on
Quote from: Arnold B. Krueger on
Lets say that they wanted to actually document the processing that they did. They would give us the Matlab code?
There is no code.
There's no spoon either.  Guess repeatability wasn't one of the goals of the BS paper. Just a farce to prime the pump for MQA eh?  cheers,  AJ


But isn't reproducibility one of the main principles of the scientific method? Oh, it is:

http://en.wikipedia.org/wiki/Reproducibility

The AES gives awards to such papers?

There is no requirement for any schmuck to be able to reproduce a scientific experiment.  The requirement is for others schooled in the art.  Not lay people pretending to understand the topic.
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

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

Reply #1005 –
Quote from: Kohlrabi on
So, this thread falls under ToS #14 now?
The AES frowns on papers used exclusively for describing promotional or commercial products. They have to show other "merit":

"Commercialism: A manuscript which is based on a commercial product should be reviewed extremely carefully to determine the real scientific content. If a manuscript has no other merit than as a description of the product, it is not acceptable. This requirement is especially important in articles that provide technical results without an adequate description of a device's operation."

http://www.aes.org/journal/authors/guidelines/

So perhaps this is why their MQA technology had to be announced after these related BS papers got published and not before.

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

Reply #1006 –
Quote from: amirm on
all the parameters are given.
They're not. The documentation for that toolbox is freely available on line. Take a look. You will find that several user adjustable parameters are not documented in the paper.

Cheers,
David.

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

Reply #1007 –
Quote from: amirm on
There is no requirement for any schmuck to be able to reproduce a scientific experiment.  The requirement is for others schooled in the art.

So shysters only. Those who understand the business field of Hi-Re$. Hmmm, doesn't sound very scientific or repeatable.
But we wouldn't want repetition prior to the launch of MQA anyway, the $cam works better that way.

cheers,

AJ

Loudspeaker manufacturer

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

Reply #1008 –
Quote from: amirm on
There is no requirement for any schmuck to be able to reproduce a scientific experiment.  The requirement is for others schooled in the art.  Not lay people pretending to understand the topic.

Which you've demonstrated that you do not (need I remind you of LTI system basics?), so why talk down on more knowledgeable people? Oh right, it's you.

But since you have matlab, please post the 1-2 lines of code here that produce the exact same 44.1 kHz filter.
"I hear it when I see it."

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

Reply #1009 –
Quote from: 2Bdecided on
You will find that several user adjustable parameters are not documented in the paper.
David, does "filter builder" apply dither or is a separate dither toolbox required ?

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

Reply #1010 –
Quote from: amirm on
Quote from: mzil on
Quote from: ajinfla on
Quote from: amirm on
Quote from: Arnold B. Krueger on
Lets say that they wanted to actually document the processing that they did. They would give us the Matlab code?
There is no code.
There's no spoon either.  Guess repeatability wasn't one of the goals of the BS paper. Just a farce to prime the pump for MQA eh?  cheers,  AJ


But isn't reproducibility one of the main principles of the scientific method? Oh, it is:

http://en.wikipedia.org/wiki/Reproducibility

The AES gives awards to such papers?

There is no requirement for any schmuck to be able to reproduce a scientific experiment.


Of course not. Your answers to reasonable questions about the reproducability of the experiment in this paper shows that you don't seem to know what it would take even a very knowledgeable person to accurately reproduce this experiment.

Here is the command syntax that would likely be used:

http://www.mathworks.com/help/signal/ref/f...gn.lowpass.html

Quote
fdesign.lowpass

Syntax
D = fdesign.lowpass
D = fdesign.lowpass(SPEC)
D = fdesign.lowpass(SPEC,specvalue1,specvalue2,...)
D = fdesign.lowpass(specvalue1,specvalue2,specvalue3,specvalue4)
D = fdesign.lowpass(...,Fs)
D = fdesign.lowpass(...,MAGUNITS)

Description

D = fdesign.lowpass constructs a lowpass filter specification object D, applying default values for the default specification string 'Fp,Fst,Ap,Ast'.

D = fdesign.lowpass(SPEC) constructs object D and sets the Specification property to the string in SPEC. Entries in the SPEC string represent various filter response features, such as the filter order, that govern the filter design. Valid entries for SPEC are shown below. The strings are not case sensitive.

'Fp,Fst,Ap,Ast' (default spec)
'N,F3db'
'N,F3db,Ap' *
'N,F3db,Ap,Ast' *
'N,F3db,Ast' *
'N,F3db,Fst' *
'N,Fc'
'N,Fc,Ap,Ast'
'N,Fp,Ap'
'N,Fp,Ap,Ast'
'N,Fp,Fst,Ap' *
'N,Fp,F3db' *
'N,Fp,Fst'
'N,Fp,Fst,Ast' *
'N,Fst,Ap,Ast' *
'N,Fst,Ast'
'Nb,Na,Fp,Fst' *


etc.

Here's a chance to redeem yourself, Amir.  Tell us what parameters we need and what their values are, based on the article.

Amir, no answer or an incorrect answer is a strong indication that you have described yourself with the following somewhat indelicate wording: "There is no requirement for any schmuck to be able to reproduce a scientific experiment."

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

Reply #1011 –
Quote from: Kees de Visser on
Quote from: 2Bdecided on
You will find that several user adjustable parameters are not documented in the paper.
David, does "filter builder" apply dither or is a separate dither toolbox required ?

Sorry Kees, I don't know. Dither is absent from the equivalent tool box in my 2009 release, but may have been added since. You would normally use double precision floating point in matlab, so don't dither until you need integers for playback or integer wave files.

Cheers,
David.

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

Reply #1012 –
This whole BS test farce is now moot IMO, given that we now have the real McCoy from the BS company: MQA.
Now we need to see them demo their new MQA $cam at shows with the same Meridian DSP7200 rig, vs the TPDF 16/44 version of the master, so that the vast improvement in SQ can be "heard".
Of course, part of the con involving this BS paper, is that there is no TPDF 16/44 "CD" version of the 2L master. What a coincidence. 

cheers,

AJ
Loudspeaker manufacturer

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

Reply #1013 –
Now, thanks to this paper, they can point to it should anyone contest that the difference offered by MQA isn't actually audible. They'll contend: "But didn't you get the memo: the 2nd offered conclusion in the AES paper's abstract? It noted that only truly high fidelity audio systems can reveal the difference, so if your pedestrian $23K speakers don't cut it, that's because they are half the quality of the ones we used."

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

Reply #1014 –
Quote from: amirm on
There is no requirement for any schmuck to be able to reproduce a scientific experiment.  The requirement is for others schooled in the art.  Not lay people pretending to understand the topic.


Hmm, well, JJ is a member of this forum as well as AES and is, safe to say, at least *passingly* familiar with MATLAB.  I would imagine some other members of the AES are too.  Are they 'schmucks'?  They are, after all , the primary audience for that peer-reviewed prize winning convention paper.

There's other people at HA who know MATLAB too.  Hell, I have labmates who use it, and we're just a lowly *biologists*.

So, who here at HA *do* you think is qualified to reproduce this experiment and results from the information given?  Anyone besides yourself?



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

Reply #1015 –
Quote from: mzil on
Now, thanks to this paper, they can point to it should anyone contest that the difference offered by MQA isn't actually audible. They'll contend: "But didn't you get the memo: the 2nd offered conclusion in the AES paper's abstract? It noted that only truly high fidelity audio systems can reveal the difference, so if your pedestrian $23K speakers don't cut it, that's because they are half the quality of the ones we used."



The paper looks to me like a PR coup for Meridian in particular, and the golden eared segment of the audio industry in general.

Unfortunately past bastions of scientific approaches to audio have such as Dolby have passed to a new generation of leadership who buy into this sort of thing.

I'm "Looking Forward" to several of Stereophile's columnists taking a few victory laps, based on it.

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

Reply #1016 –
Quote from: krabapple on
Quote from: amirm on
There is no requirement for any schmuck to be able to reproduce a scientific experiment.  The requirement is for others schooled in the art.  Not lay people pretending to understand the topic.


Hmm, well, JJ is a member of this forum as well as AES and is, safe to say, at least *passingly* familiar with MATLAB.  I would imagine some other members of the AES are too.  Are they 'schmucks'?  They are, after all , the primary audience for that peer-reviewed prize winning convention paper.

There's other people at HA who know MATLAB too.  Hell, I have labmates who use it, and we're just a lowly *biologists*.

So, who here at HA *do* you think is qualified to reproduce this experiment and results from the information given?  Anyone besides yourself?


I think that we may already have a real world answer to that, based on Amir's response to http://www.hydrogenaud.io/forums/index.php...st&p=883605

It appears that Matlab licenses are just under $2K, so there is an element of elitism to its use.

Whether the same thing can be done with Octave or some other alternative becomes an interesting question:

http://octave.sourceforge.net/signal/overview.html

Of course the golden ears will argue that no open source software can really duplicate the output of the high priced spread.

OTOH, part of affirming results by means of an independent experimenter can/should include using other, comparable tools.  If only a certain tool provides the same results, it is possible that the observed results with it are the result of some glitch within the tool.

Given the fact that Meridian's use of Matlab inexplicably diverged from the stated purpose of the paper...

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

Reply #1017 –
Quote from: mzil on
Now, thanks to this paper, they can point to it should anyone contest that the difference offered by MQA isn't actually audible. They'll contend: "But didn't you get the memo: the 2nd offered conclusion in the AES paper's abstract? It noted that only truly high fidelity audio systems can reveal the difference, so if your pedestrian $23K speakers don't cut it, that's because they are half the quality of the ones we used."

Quote from: ajinfla on
This whole BS test farce is now moot IMO, given that we now have the real McCoy from the BS company: MQA.


You too look like you are going to blow a blood vessel over this . 

So let me share with you some good news, bad news.  Which one do you want to hear first?  Ah, I figured you would pick the bad news first. 

Bad News:
This is a perceptually lossless scheme for high-resolution audio.  Stated (example) efficiency is in the order of 10:1 with respect 24/192Khz, bringing its data rate from nearly 10 mbit/sec to less than that of the CD, i.e. 1 mbit/sec.  So there goes the argument that it takes 6 times more to store high resolution audio.  The encoding (I think) is layered allowing a lossy 16-bit base layer without a special decoder.  The efficiency comes from going from the "rectangle" of bit depth and sampling rate to a much more customized shape where only the data that is a) not noise and b) is important perceptually is saved.  There is no reliance on masking and such but rather preserving the "timing" of the signal (xnor: you get to go nuclear now  ) in addition to frequency domain.

They have been working with both Sony Music and WMG (Warner) on testing and development of the technology so I would expect both of those labels to be present at their CES announcement.

Good news:
The world needs a new audio format like a hole in the head.  The audience for high-resolution audio is enthusiasts who a) don't care about bandwidth or storage costs and b) won't accept any argument of perceptual equality.  They will insist on getting the original bits.

Getting a new decoder into all manner of devices and players when it comes from a tiny competitive company called Meridian is a non-starter. 

While the format is also targeted at archiving, I expect zero uptake there as the cost of storage there compared to production is negligible. 

There is this inside story of tech company executives who dream of waking up one day and being in "content business" and rubbing shoulders with the stars in music/movies.  The calling is quite strong and folks jump at any idea, no matter how stupid from economical point of view, and jump with both feet.  Who doesn't want to stand on the stage with Sony and Warner executives on stage.  No longer do you show up with some boxes on a tech show where there is no attention from mainstream press.

Music labels only care about MGs (minimum guarantees) these days.  They will sleep with AJ and Mzil if they showed up with a $500,000 check.  They will hand you their catalog, wish you good luck and hope the next tech exec falling victim to above.

So Meridian will put up some tracks.  Build the decoders and such for this.  A couple of years from now hopefully they wake up and realize what a distraction and financial drain this has been and mothball the efforts.  At least I hope it only takes that long.

So don't have a heart attack over this.  There is no "there there."  It is a solution looking for a problem that the end customer does not have.  Yet it creates friction in delivering the same.

I told you there is no money in audio business, didn't I? 
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

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

Reply #1018 –
Quote from: 2Bdecided on
Quote from: amirm on
all the parameters are given.
They're not. The documentation for that toolbox is freely available on line. Take a look. You will find that several user adjustable parameters are not documented in the paper.

Cheers,
David.

Take a look?  I already post filters I created in Matlab.  I don't need to look at help files online.  The design parameters of the filter are documented.  That doesn't mean they are going to hold your hands and give you everything you need to type in Matlab.

What parameters are you worried about that impact audibility of the filters?
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

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

Reply #1019 –
Quote from: amirm on
Stated (example) efficiency is in the order of 10:1 with respect 24/192Khz, bringing its data rate from nearly 10 mbit/sec to less than that of the CD, i.e. 1 mbit/sec.
Isn't it ironic how you doubted the 12bit/32kHz figure I gave for the actual information content of contemporary music earlier, and now you yourself say it's a good thing that you can compress 24bit/192kHz by a factor of ten, which fits pretty well to something like 12-13 bits and 32-38 kHz. Keep in mind that according to my information the 13(?) MSBs of the new format store the lossless information, so the lossy part will in most cases only contain noise anyway. That you can compress the files that much without damaging the perceptual result shows that the actual information content of (some) contemporary music is in the range I stated earlier, and that delivery of 24bit/192kHz is wasteful and pointless. The compression efficiency shows that in the most obvious manner.

Quote from: amirm on
Good news:
The world needs a new audio format like a hole in the head.  The audience for high-resolution audio is enthusiasts who a) don't care about bandwidth or storage costs and b) won't accept any argument of perceptual equality.  They will insist on getting the original bits.
And why should we accept a worse implementation of lossyWAV which delivers intentionally crippled data to non-Meridian customers?
It's only audiophile if it's inconvenient.

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

Reply #1020 –
Quote from: amirm on
Quote from: 2Bdecided on
Quote from: amirm on
all the parameters are given.
They're not. The documentation for that toolbox is freely available on line. Take a look. You will find that several user adjustable parameters are not documented in the paper.

Cheers,
David.

Take a look?  I already post filters I created in Matlab.  I don't need to look at help files online.  The design parameters of the filter are documented.  That doesn't mean they are going to hold your hands and give you everything you need to type in Matlab.

What parameters are you worried about that impact audibility of the filters?

I don't have the list on my phone, but you ask the wrong question. We're talkng about re-creating the first experiment that showed this class of filter is just about audible in some specific circumsances, and you want me to guess which filter parameters I can change without impacting audibility? Two months ago there was no evidence that any parameter related soley to ultrasonic performance was audible. Even now, there's no evidence that the exact same filters, equipment and listeners can recreate the experiment. It would be ridiculous to second guess what changes might be audible when designing a repeat experiment, unless you want to intentionally test that difference. We don't. We want to recreate the original experiment as closely as possible.

It would be possible to get close based on the published data, but in this context that's not good enough IMO.

Cheers,
David.

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

Reply #1021 –
Quote from: amirm on
I already post filters I created in Matlab.  I don't need to look at help files online.  The design parameters of the filter are documented.  That doesn't mean they are going to hold your hands and give you everything you need to type in Matlab.


Please post the URL of the post with your Matlab documentation, Amir.

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

Reply #1022 –
Amir, why aren't you just honest for one single time and just say that you don't know what the precise parameters are to reproduce the exact same filters?

Anyway, as WernerO pointed out, they basically simulated a mix of A/D and mastering filters. Both don't tell you how it will sound with a less steep filter in the D/A conversion process.
You can use a ultra steep lowpass filter when exporting a CD mixdown .. so what? Whenever someone is listening to it, it will have to have run through a filter that has a lot less ringing, and potentially no pre-ringing.

The only way to directly "get" (let's not say hear) such filters is by applying them manually on material with higher sampling rate, e.g. 192 kHz. That has nothing to do with real-world playback.
"I hear it when I see it."

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

Reply #1023 –
Quote from: Arnold B. Krueger on
Quote from: amirm on
I already post filters I created in Matlab.  I don't need to look at help files online.  The design parameters of the filter are documented.  That doesn't mean they are going to hold your hands and give you everything you need to type in Matlab.


Please post the URL of the post with your Matlab documentation, Amir.

What?
Amir
Retired Technology Insider
Founder, AudioScienceReview.com
 

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

Reply #1024 –
Quote from: xnor on
Amir, why aren't you just honest for one single time and just say that you don't know what the precise parameters are to reproduce the exact same filters?

Lot of good it did me the last time I shared personal data related to this conversation.  You guys are not interested in such data.  Chu who brought up this topic says can't run any test because he doesn't even have a computer.  Arny has only run one double blind test in months of these discussions.  That one test was his own bloody test which he would not run after hundreds of posts and requests.  Steven (Krab) has not run any tests.  Mzil has cheated on the one test he did run.  AJ has not run any test.  You xnor, have refused to run all tests on moral grounds.  I came here and even ran David's test which he himself has not run.  Our two kind moderators have not run or reported on any of these tests either.

So no, when you all start to show some interest in actual data as opposed to searching high and low for your future talking points to dismiss these results, I will join you.  For now you can pursue the witch-hunt yourself.

"Don't know the exact filter parameters..." Are you kidding me? 

Quote
Anyway, as WernerO pointed out, they basically simulated a mix of A/D and mastering filters.

No, what he pointed out was this:

Quote from: WernerO on
Quote from: xnor on
The paper is about simulating real-world anti-imaging filters, not resampling filters.

This beggars belief. Please go back and re-read the paper's abstract. Do you actually understand anything of this?
Amir
Retired Technology Insider
Founder, AudioScienceReview.com