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post #271 of 284 Old 06-06-2014, 12:33 PM
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Quote:
Originally Posted by Chu Gai View Post

Got a title for the paper?

"A Digital Domain Listening Test for High Resolution"

Author: Vanderkooy, John
Affiliation: University of Waterloo, Waterloo, Ontario, Canada
AES Convention:129 (November 2010) Paper Number:8203
Publication Date:November 4, 2010
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post #272 of 284 Old 06-07-2014, 08:45 PM - Thread Starter
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Hello arny,
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Originally Posted by arnyk View Post

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Originally Posted by UndersAVS View Post


I'm aware that IM distortion produced loud enough and far enough from the main tone will be audible.

Probably not my preferred way to express the key idea. The key idea I was trying to express is that ultrasonic program material can create audible artifacts via the mechanism we call IM.
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I don't see the relation to the jitter graphs provided by amir.

None intended. The material about IM ended up where it was posted because someone stated categorically that ultrasonic program material can not possibly create audible artifacts. http://www.avsforum.com/t/1531357/jitter/210#post_24783749

Oh. I didn't realize that I was stating that. I don't recall any mention of ultrasonic material in the question to which I responded. The question was vague and I answered vaguely without asking for more clarification simply because I wasn't concerned with providing a 'right' or 'wrong' answer. Quite frankly, I've been hoping to gain more clarification as to the reasons amir feels there may be audible differences between the spdif and hdmi measures in the graph. Several pages deep into the thread and that hasn't happened.

I think forum member JHAZ summed up things very nicely in the parent thread 'optical vs hdmi' (or something like that). So far, no one has written more lucidly or thoroughly on the topic.
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I noticed that you added numbers along the horizontal axis on the Pioneer illustration (50, 100, 150, etc). What do they represent?

That would be in reference to this illustration, right?



The added 50 and 100 numbers refer to peak frequency deviation from the carrier.
IM is not relevant to this particular illustration.

Okay, now I see what you were communicating with the annotations; 12,030Hz, 12,050kHz., 12,100Hz....
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post #273 of 284 Old 06-07-2014, 08:49 PM - Thread Starter
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Originally Posted by Chu Gai View Post

I think you missed the joke.

I thought it would be fairly obvious.
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post #274 of 284 Old 06-07-2014, 09:03 PM - Thread Starter
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Don,
I checked out the upcoming events. Plenty of good Russian music on the itinerary; pieces from the ballets. My favorite period/music is early 20th century Russian: Prokofiev and Stravinsky in particular. Aside from that, Tchaikovsky and Rachmaninoff. Borodin wrote some fab works too. Too bad I don't live in the vicinity because I would love to hear those upcoming performances.
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post #275 of 284 Old 06-07-2014, 09:50 PM
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Yeah, should be an interesting season. Guess I'd better practice this summer... smile.gif Stop by if you're ever in the area.

"After silence, that which best expresses the inexpressible, is music" - Aldous Huxley
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post #276 of 284 Old 06-08-2014, 04:01 AM
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Regarding the HDMI SPDIF chart above...

If the test tone were, say 1.2khz instead of 12khz - would the frequency spacing (30 - 60 - 90) of the jitter artifacts remain the same? Amplitude change?

I'll be back later...


links::: 1.5RQ > digits > 1177a > OpenDRC-DI > DEQ2496 > DAC2 > KCT > FPB 350mcx > reQuest > Sweetspot
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post #277 of 284 Old 06-08-2014, 05:24 AM
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Quote:
Originally Posted by RayDunzl View Post

Regarding the HDMI SPDIF chart above...

If the test tone were, say 1.2khz instead of 12khz - would the frequency spacing (30 - 60 - 90) of the jitter artifacts remain the same? Amplitude change?

Yes, the spacing stays the same since it is the same as the modulating frequency.

If for example the modulating frequency is say 30 Hz, then the first pair of sidebands are +/- 30 Hz from the carrier or test frequency. Any remaining sidebands are also spaced by 30 Hz in this example.

The amplitude and center frequencies of the first pair of sidebands are a good guide to the modulation index of the jitter. The carrier frequency, the modulating frequency and the modulation index can be used to estimate audibility from sources like Zwicker and Fastl (2007)

The listening test files that anybody should be able to download from https://www.dropbox.com/sh/0ov07gu5azijtfz/AAD5acmrMz2o9G4MUCm_6kMPa are a demonstration of this that is designed for use with the Foobar2000 ABX Comparator.

The usual rule of thumb is that dropping the carrier frequency (say from 12 KHz to 1.2 Kz) has a proportional effect on amplitude of the sidebands. So dropping the carrier frequency or the test frequency (different names for the same thing) by a factor of 10 drops the amplitude of the sidebands for a given amount of modulation by a factor of 10, or an order of magnitude or 20 dB (again different names for the same thing)

This paper has a lot the relevant theory and facts:

http://www.iet.ntnu.no/courses/fe8114/files/Report_audiodac.pdf, pages 6-20. I'm reviewing it for accuracy, but what I've seen so far looks pretty interesting.

This article is good summary of some of the same facts and theory:

http://en.wikipedia.org/wiki/Frequency_modulation
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post #278 of 284 Old 06-11-2014, 10:08 PM
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Quote:
Originally Posted by amirm View Post
The file itself contains no jitter whatsoever. Nor does it simulate "subtle timing inaccuracies." Remember, a file sitting on your hard disk before being played is just a bunch of digital audio samples. it is "perfect" in that regard. We can copy it 100 times and the last copy will be identical to first. So no timing problem exists or can exist in a digital file on a computer.
You aren't kidding. I've been hip deep in a debate about Ethernet delivered audio on popular software media players (JRiver, Foobar, MM, etc) at Polk Audio where they conflate the buffer that drives an S/PDIF output to that of a computers data buffer filling with pull requests over the wire.

When I point out you can actually start a track, pause the track, pull the Ethernet connection, then hit play, then pause, then play again that there is no jitter from the perspective of the Ethernet layer. That the jitter that is introduced is from the S/PDIF cable and clock-recovery of the DAC.

Further more Darque Knight is trying to say the data is somehow not computer data on the Ethernet Cable but 'Wide Band' and real time.

Keep trying to explain to them that as far as the computer is concerned data is just data when it's on a packet network.

Been interesting to say the least. I used your above post as a corroboration in addition to some articles by Steven Nugent of Emprical Audio.

I don't think it has fully registered with some.
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post #279 of 284 Old 06-12-2014, 12:03 AM
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Out of curiosity: are you using speakers or headphones to check for the audibility of jitter effects? There is some evidence that headphones are better for this purpose (Kaoru Ashihara):
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Distortions due to very small jitter may be smaller than distortions due to non-linear characteristics of loudspeakers. Ashihara and Kiryu [8] evaluated linearity of loudspeaker and headphones. According to their observation, headphones seem to be more preferable to produce sufficient sound pressure at the ear drums with smaller distortions than loudspeakers.
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post #280 of 284 Old 06-12-2014, 05:07 AM
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Quote:
Originally Posted by Habanero Monk View Post
You aren't kidding. I've been hip deep in a debate about Ethernet delivered audio on popular software media players (JRiver, Foobar, MM, etc) at Polk Audio where they conflate the buffer that drives an S/PDIF output to that of a computers data buffer filling with pull requests over the wire.

When I point out you can actually start a track, pause the track, pull the Ethernet connection, then hit play, then pause, then play again that there is no jitter from the perspective of the Ethernet layer. That the jitter that is introduced is from the S/PDIF cable and clock-recovery of the DAC.

Further more Darque Knight is trying to say the data is somehow not computer data on the Ethernet Cable but 'Wide Band' and real time.

Keep trying to explain to them that as far as the computer is concerned data is just data when it's on a packet network.

Been interesting to say the least. I used your above post as a corroboration in addition to some articles by Steven Nugent of Emprical Audio.

I don't think it has fully registered with some.
Just a few encouraging words. I've been following this thread over at the other forum as a non-member and I greatly appreciate your high quality efforts to spread true facts and use well reasoned arguments.
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post #281 of 284 Old 06-12-2014, 05:10 AM
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Quote:
Originally Posted by Kees de Visser View Post
Out of curiosity: are you using speakers or headphones to check for the audibility of jitter effects? There is some evidence that headphones are better for this purpose (Kaoru Ashihara):
Agreed. IME hearing various kinds of noises, distortions and artifacts is one of those things that good headphones and earphones foster. Most rooms produce echoes that reduce the audibility of these things.
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post #282 of 284 Old 06-12-2014, 08:22 AM
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Originally Posted by arnyk View Post
Just a few encouraging words. I've been following this thread over at the other forum as a non-member and I greatly appreciate your high quality efforts to spread true facts and use well reasoned arguments.
I find it immature that I asked 5 pointed questions and they just won't go near them.

They have found themselves painted into a corner and know soon as they step they will have paint on their shoes.

They simply can't admit that their understanding was incorrect.

Darque Knight is particularly, well 'dirty' is too strong a word but disingenuous doesn't sum it up either, when it came to his trying to paint variations in AM as it pertains to Ethernet signaling itself and the entire protocol stack.

Really a smoke and mirrors routine of a particularly nominally skilled magician. One where I can spot the obvious subterfuge but where all the believers see an elephant suddenly disappearing whilst on stage.

He started with an analogy of Shipping car parts and trying to make it sound like entire cars are being shipped.

I pointed out parts are parts. They are assembled at a factory after offloaded and then put in a dealership. The person that just drove the car off the lot has no idea that the parts that made up his car arrived on two different ships that arrived 4 hours apart.

Then he went on to baking a cake analogy and when that didn't work out something about termite infested and warped, chipped, 2X4 construction materials.

It's been bizzaro.

Last edited by Habanero Monk; 06-12-2014 at 08:43 AM. Reason: readability
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post #283 of 284 Old 06-12-2014, 09:35 AM
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Quote:
Originally Posted by Habanero Monk View Post
I find it immature that I asked 5 pointed questions and they just won't go near them.

They have found themselves painted into a corner and know soon as they step they will have paint on their shoes.

They simply can't admit that their understanding was incorrect.

Darque Knight is particularly, well 'dirty' is too strong a word but disingenuous doesn't sum it up either, when it came to his trying to paint variations in AM as it pertains to Ethernet signaling itself and the entire protocol stack.

Really a smoke and mirrors routine of a particularly nominally skilled magician. One where I can spot the obvious subterfuge but where all the believers see an elephant suddenly disappearing whilst on stage.

He started with an analogy of Shipping car parts and trying to make it sound like entire cars are being shipped.

I pointed out parts are parts. They are assembled at a factory after offloaded and then put in a dealership. The person that just drove the car off the lot has no idea that the parts that made up his car arrived on two different ships that arrived 4 hours apart.

Then he went on to baking a cake analogy and when that didn't work out something about termite infested and warped, chipped, 2X4 construction materials.

It's been bizzaro.
Not that unusual. You can see me struggling with the AVS version of a similar situation here: Debate Thread: Scott's Hi-res Audio Test
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post #284 of 284 Old 06-12-2014, 09:53 AM
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Quote:
Originally Posted by Habanero Monk View Post

They simply can't admit that their understanding was incorrect.
Well, at some point you just have to accept that some people are just so far out that logic reasoning just don't apply to them.


I've been in numerous similar discussions regarding the sonic benefits of using audiophile USB-, Ethernet- and powercords, where you suddenly find yourself arguing against arguments and explanations so bizarre, you can't even begin to build a logical argument against their "truths", because they are so far off the chart.


My advice is to spend barely enough time on these nutcases to make your point clear to the broader mass, and then spend the rest of the effort available not on convincing him/her that he/she is wrong, but instead spend that time and effort on caring about your loved ones instead. But you seem like an intelligent guy so you've already figured that out, I am certain.
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