24/192 music downloads are useless??

[avnetguy]

You may, or not, want to read some of this thread:
24/192 Music Downloads and why they make no sense - Page 5 - AVS Forum

OMG that was funny, I almost spewed coke through my nose with the "How audiophiles believe gear is designed" picture.

I just skimmed the umm, we'll call it a discussion I guess, and the one guy there seems to have good knowledge. I also noted who the OP was, lol.

Steve

 

[avnetguy]

So I'm wondering if anyone followed/understood my digital sampling description? You also may have noticed my lack of using the clingy term Nyquist. Rather than me explaining why, I found a PDF article that gives some good information, at the very least I think it tends not to mislead people to thinking Nyquist is more than it is in the real world.

Sampling: What Nyquist Didn’t Say, and What to Do About It

Steve

 

[mtrycrafts]

So I'm wondering if anyone followed/understood my digital sampling description? You also may have noticed my lack of using the clingy term Nyquist. Rather than me explaining why, I found a PDF article that gives some good information, at the very least I think it tends not to mislead people to thinking Nyquist is more than it is in the real world.

Sampling: What Nyquist Didn’t Say, and What to Do About It

Steve

I am not sure why the author is picking exactly 2x sampling and trying to discredit it when the theorem says greater than 2x which is not exactly 2x.

Yet, the theorem works, period. Reconstruction works and you don't need 4x sampling for 20kHz, period.

 

[mtrycrafts]

Could you point us to the post so we don't have to read the whole thread?

Too many pages?
Perhaps the discussion on page 5? Maybe pg 4 too.
Follow Arny's posts. He also happens to be the person involved in the ABX box back in its origins.
Reconstruction, filtering the whole works..

 

[avnetguy]

I am not sure why the author is picking exactly 2x sampling and trying to discredit it when the theorem says greater than 2x which is not exactly 2x.

Yet, the theorem works, period. Reconstruction works and you don't need 4x sampling for 20kHz, period.

The author was just pointing out potential pitfalls and practical limitations in example situations, nothing more. He does make a good point, I thought anyways, that the Nyquist shouldn't be used as a hard wall.

BTW, I understand what you are saying and you've stated many times that you have total faith in the reconstruction filter. I on the other hand do not just from the fact that I don't understand it yet but I'm trying to learn so please don't take offense to that.

Steve

 

[mtrycrafts]

The author was just pointing out potential pitfalls and practical limitations in example situations, nothing more. He does make a good point, I thought anyways, that the Nyquist shouldn't be used as a hard wall.

BTW, I understand what you are saying and you've stated many times that you have total faith in the reconstruction filter. I on the other hand do not just from the fact that I don't understand it yet but I'm trying to learn so please don't take offense to that.

Steve

No offence taken. The simple answer is to put an O scope of some kind to the analog output on a CD player and run a test CD and look at the quality of the tones, not what happens inside the processing chain. I think you hear the analog output and not what just happened inside the guts of the system That is for the doctors to check
ps. it might be even better to have a test disc recorded at both sampling rates, redbook and higher and compare the 20kHz analog outputs. Maybe Rives audio might have one or know who might?

 

[avnetguy]

But what happens through the entire processing chain is what intrigues me. I'm very familiar with everything from analog to A/D and the "digital guts" up to the D/A so I'd like to learn the end of the process. So far the reconstruction seems to contain nothing to elaborate, sometimes as simple as two low pass filters, a very steep filter followed by a moderately steep filter. Based on what I'm seeing in the "digital guts" at high frequencies I'd expect much more to be there. I tried to snag a DSO from one of the other departments but they are heavily used so until then I'll just do more reading research.

Steve

 

[mtrycrafts]

But what happens through the entire processing chain is what intrigues me. I'm very familiar with everything from analog to A/D and the "digital guts" up to the D/A so I'd like to learn the end of the process. So far the reconstruction seems to contain nothing to elaborate, sometimes as simple as two low pass filters, a very steep filter followed by a moderately steep filter. Based on what I'm seeing in the "digital guts" at high frequencies I'd expect much more to be there. I tried to snag a DSO from one of the other departments but they are heavily used so until then I'll just do more reading research.

Steve

That is interesting, an internist.
So you made the statement that you need 4X sampling to recreate, in essence, a 20kHz sine wave properly from what happens on the inside? Interesting. I am not the person to even hint where to start on your journey other than, in this case, either contact Gene here, or join AVS and see if you can get Arnyk to respond. Shoot him a personal. He is very responsive.

 

[PENG]

That is interesting, an internist.
So you made the statement that you need 4X sampling to recreate, in essence, a 20kHz sine wave properly from what happens on the inside? Interesting. I am not the person to even hint where to start on your journey other than, in this case, either contact Gene here, or join AVS and see if you can get Arnyk to respond. Shoot him a personal. He is very responsive.

Did he really make that statement about needing 4X? I don't recall that, and I got the impression that he understands what the theory says, i.e. you need only >2X, but he is having trouble seeing how it can be realized in real world applications. Why he would doubt (don't really know if he does or not) that is beyond me.. I mean I also don't understand how they got to the moon, I can't build a vehicle to get me there but I know someone could, and did, got there, and back.

By the way, I also know I only need 1 point on a piece of paper for me to draw a perfect circule, if I know the center, got my point?

 

[avnetguy]

Yup, mtrycrafts is correct, I did in fact make that statement which I followed with that it was taken from my perspective of the digital waveform alone. I did make that point a few times in different posts I believe, sorry if it was unclear.

Let me try an illustrate my point one last time with an analogy. To me, looking at the digital data and then the proposed output is akin to saying an DVD upscaled to 1080p will look just as good as a one mastered for Bluray. Thou not a perfect analogy, it's the best I can think of right now.

BTW, I would glady accept any knowledge/explanation on this part, probably best done via PMs I would think, so if anyone out there does know please feel free to shoot me a msg. The AVS idea however is right out, everyone in that thread (not knocking knowledge here) is far too argumentative for me and that's just not my thing.

Steve

 

[avnetguy]

Did he really make that statement about needing 4X? I don't recall that, and I got the impression that he understands what the theory says, i.e. you need only >2X, but he is having trouble seeing how it can be realized in real world applications. Why he would doubt (don't really know if he does or not) that is beyond me.. I mean I also don't understand how they got to the moon, I can't build a vehicle to get me there but I know someone could, and did, got there, and back.

By the way, I also know I only need 1 point on a piece of paper for me to draw a perfect circule, if I know the center, got my point?

As you said, I completely understand the theory and it is the real world practical limitations/application on the output side that is confusing. The digital realm is crystal clear to me, the analog side (in some areas) not so much.

Steve

 

[TLS Guy]

No offence taken. The simple answer is to put an O scope of some kind to the analog output on a CD player and run a test CD and look at the quality of the tones, not what happens inside the processing chain. I think you hear the analog output and not what just happened inside the guts of the system That is for the doctors to check
ps. it might be even better to have a test disc recorded at both sampling rates, redbook and higher and compare the 20kHz analog outputs. Maybe Rives audio might have one or know who might?

Here is the analog output from a 1984 Revox B225. Frequency is 5 kHz

Here is the same player with a 20 kHz tone.

This was a unit I bought on 1984. I took the pictures after servicing prior to sale.

Even the 20 kHz waves is perfect and that's a first generation player!

The waves were from the Stereophile test CD.

 

[mtrycrafts]

Yup, mtrycrafts is correct, I did in fact make that statement which I followed with that it was taken from my perspective of the digital waveform alone. I did make that point a few times in different posts I believe, sorry if it was unclear.

Let me try an illustrate my point one last time with an analogy. To me, looking at the digital data and then the proposed output is akin to saying an DVD upscaled to 1080p will look just as good as a one mastered for Bluray. Thou not a perfect analogy, it's the best I can think of right now.

BTW, I would glady accept any knowledge/explanation on this part, probably best done via PMs I would think, so if anyone out there does know please feel free to shoot me a msg. The AVS idea however is right out, everyone in that thread (not knocking knowledge here) is far too argumentative for me and that's just not my thing.

Steve

Here is the analog output from a 1984 Revox B225. Frequency is 5 kHz

Here is the same player with a 20 kHz tone.

This was a unit I bought on 1984. I took the pictures after servicing prior to sale.

Even the 20 kHz waves is perfect and that's a first generation player!

The waves were from the Stereophile test CD.

Thanks, TLS I never had a doubt of the outcome for a very long time now Just don't have the tools and knowledge in my hands to convince him.

Just hope avnetguy sees it and takes it to heart. After all, we do listen to the analog output signals from the D/A, not what is gurgled on the insides. And, he takes it to hear that it was done correct;ly way back when the dinosaurs ruled, no?

 

[mtrycrafts]

Did he really make that statement about needing 4X? I don't recall that, and I got the impression that he understands what the theory says, i.e. you need only >2X, but he is having trouble seeing how it can be realized in real world applications. Why he would doubt (don't really know if he does or not) that is beyond me.. I mean I also don't understand how they got to the moon, I can't build a vehicle to get me there but I know someone could, and did, got there, and back.

By the way, I also know I only need 1 point on a piece of paper for me to draw a perfect circule, if I know the center, got my point?

That is what started the exchange between us.

I am sure you understand how we got to the moon astronaut, spaceship with lots of power and the moon, of course and off you go. The millions of small details is the tough part

And, if you don't know the center, you make one up. Imagination is good at times.

... the analog side (in some areas) not so much.

Steve

Well, TLSguy came through with a scope trace with an 1984 CD player, no less. 5 kHz, 20 kHz. looks perfect to me as it did to him.

I would also recommend a good book on digital audio:"Principles of Digital Audio" by Ken C. Pohlmann, Mcgraw Hill

 

[TLS Guy]

Thanks, TLS I never had a doubt of the outcome for a very long time now Just don't have the tools and knowledge in my hands to convince him.

Just hope avnetguy sees it and takes it to heart. After all, we do listen to the analog output signals from the D/A, not what is gurgled on the insides. And, he takes it to hear that it was done correct;ly way back when the dinosaurs ruled, no?

I don't know about dinosaurs, I prefer giants. That unit was designed by Roger Lagadec, chief digital design engineer for Herr Willi Studer.

 

[Grador]

Let me try an illustrate my point one last time with an analogy. To me, looking at the digital data and then the proposed output is akin to saying an DVD upscaled to 1080p will look just as good as a one mastered for Bluray. Thou not a perfect analogy, it's the best I can think of right now.
Steve

I'm going to try to play off your analogy a little bit. So with a DVD upscale you are attempting to recreate data that is not there at all, which is why it will never be as good as the 1080 master. On the other hand when you are reproducing audio near the nyquist value you have some additional properties that come into play. Since you know you are reproducing sound you know that you are producing sign waves. Knowing this you can put a shaping filter in to make every one of those jagged lines in your example images into the appropriate waves. This is very different from an upscale that is attempting to take 3 pixles of information and turn them into 5, though that would be an excellent analogy for resampling up from 44.1 kHz to something higher like 192.

 

[avnetguy]

I'm going to try to play off your analogy a little bit. So with a DVD upscale you are attempting to recreate data that is not there at all, which is why it will never be as good as the 1080 master. On the other hand when you are reproducing audio near the nyquist value you have some additional properties that come into play. Since you know you are reproducing sound you know that you are producing sign waves. Knowing this you can put a shaping filter in to make every one of those jagged lines in your example images into the appropriate waves. This is very different from an upscale that is attempting to take 3 pixles of information and turn them into 5, though that would be an excellent analogy for resampling up from 44.1 kHz to something higher like 192.

Ya, as I said, the analogy weak but the point of it was being able to creating something from, well ... near nothing. Now obviously the frequency is retained so the proper amplitude is restored via the shaping (i gather you're refering to the noise shaping) filter?

Steve

 

[cpp]

This must be the month to jump on the 24/192 'Makes No Sense threads' as they are doing the very same thing at Computer Audiophile
24/192 Downloads ... and why they make no sense? | Computer Audiophile

 

[PENG]

As you said, I completely understand the theory and it is the real world practical limitations/application on the output side that is confusing. The digital realm is crystal clear to me, the analog side (in some areas) not so much.

Steve

I do understand. The detail is in the analog side, and the number of digital points is really irrelevant as long as you have the minimum required, because you know it is a Sine function. You got me interested enough now I may dig out my U text books on Analog/Digital/Communication theory still in boxes (used to be on my bookshelves but had been displaced by disc since my last move) in the basement.

 

[mtrycrafts]

I don't know about dinosaurs, I prefer giants. That unit was designed by Roger Lagadec, chief digital design engineer for Herr Willi Studer.

Well, I just meant back in time, not who designed it or how good it is.