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post #181 of 235 Old 10-21-2013, 09:02 AM - Thread Starter
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Originally Posted by CharlesJ View Post

Interesting shots. Looking at the last one, the ultrasonics is in the range of -120 dB if I am reading it correctly. One only has to compare that to the threshold of detection wink.gif

No, those are not ultrasonics. The frequency there isnt a frequency response. It is a resolution of recording (kind of similar to kBps or bitrate of MP3s, but not really), the density of it. How much data is cramped into each millisecond of recording.
It is all pictures. All it says is that the signals are different somewhat. What matters is - can we tell them apart while listening?
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post #182 of 235 Old 10-21-2013, 10:23 AM
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So, here is what we did. I chose the first album available in the highest resolution. I asked my son to write down number 1 through 10 vertically.

I applaud you for caring enough to pursue a proper test. Too many people just "choose to believe." Much better is to try it for yourself. I will mention that others have tested this stuff many times, and when the tests are done properly the results are always about 50-50. I'm not trying to talk you out of buying files and going to all the effort! It's a great exercise. But if you accept science, and logical explanations, I assure you there is zero audible difference between so-called "hi-res" files and normal CDs.

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post #183 of 235 Old 10-21-2013, 04:46 PM
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Originally Posted by grigorianvlad View Post

No, those are not ultrasonics. The frequency there isnt a frequency response. It is a resolution of recording (kind of similar to kBps or bitrate of MP3s, but not really), the density of it. How much data is cramped into each millisecond of recording.
It is all pictures. All it says is that the signals are different somewhat. What matters is - can we tell them apart while listening?

Thanks. I guess I was not reading it correctly. wink.gifbiggrin.gif
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post #184 of 235 Old 10-21-2013, 09:46 PM
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Originally Posted by grigorianvlad View Post

No, those are not ultrasonics. The frequency there isnt a frequency response. It is a resolution of recording (kind of similar to kBps or bitrate of MP3s, but not really), the density of it. How much data is cramped into each millisecond of recording.

You have absolutely no clue WTF you are talking about.
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post #185 of 235 Old 10-22-2013, 02:19 AM
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Originally Posted by grigorianvlad View Post

Quote:
Originally Posted by CharlesJ View Post

Interesting shots. Looking at the last one, the ultrasonics is in the range of -120 dB if I am reading it correctly. One only has to compare that to the threshold of detection wink.gif

No, those are not ultrasonics.

?????

Are they not components of the sound that are above the normal audible range?

Do they not correspond to the usual definition of ultrasonics?
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The frequency there isnt a frequency response.

You seem confused by the spectrogram. It is a tool for looking at frequency response, just not in the usual way.
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It is a resolution of recording (kind of similar to kBps or bitrate of MP3s, but not really), the density of it.

Not really. Resolution relates to dynamic range, not frequency response.
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How much data is cramped into each millisecond of recording.

That is dependent on both bandwidth and dynamic range.
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It is all pictures. All it says is that the signals are different somewhat. What matters is - can we tell them apart while listening?

It shows that the so-called high resolution recordings have wider bandwidth.
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post #186 of 235 Old 10-22-2013, 06:14 AM - Thread Starter
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Dear ArnyK, we are talking about sample rate, not frequency response. Look it up, please.
What those graphs show is that in 192kHz there is additional data. It is mostly at -120db and sampled at 80kHz-96kHz (not reproduced, SAMPLED!).
If you noticed, the rainbow-looking bar on the right side doesn't correspond directly with the graph itself. It just shows what color corresponds with which rate.
Thank you
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post #187 of 235 Old 10-22-2013, 07:02 AM - Thread Starter
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From Wikipedia's article on sampling rate:
Quote:
The Nyquist–Shannon sampling theorem states that perfect reconstruction of a signal is possible when the sampling frequency is greater than twice the maximum frequency of the signal being sampled, or equivalently, when the Nyquist frequency (half the sample rate) exceeds the highest frequency of the signal being sampled. If lower sampling rates are used, the original signal's information may not be completely recoverable from the sampled signal.[2] For example, if a signal has an upper band limit of 100 Hz, a sampling frequency greater than 200 Hz will avoid aliasing and would theoretically allow perfect reconstruction.
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post #188 of 235 Old 10-22-2013, 09:25 AM
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Originally Posted by grigorianvlad View Post

Dear ArnyK, we are talking about sample rate, not frequency response. Look it up, please.

Sample rate sets the Nyquist frequency, which is the bandpass limit or the extent of the frequency response of a digital channel.

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

The Wikipedia article http://en.wikipedia.org/wiki/Sampling_rate says just that.

"The Nyquist–Shannon sampling theorem states that perfect reconstruction of a signal is possible when the sampling frequency is greater than twice the maximum frequency of the signal being sampled, or equivalently, when the Nyquist frequency (half the sample rate) exceeds the highest frequency of the signal being sampled."

If you can quote that and not understand that sample rate and maximum possible frequency response are intimately tied together with a 2:1 ratio, then you have very serious reading comprehension problems. In fact your problem with reading English would appear to be dire and nearly fatal!
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What those graphs show is that in 192kHz there is additional data.

Of course. Never said otherwise.
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It is mostly at -120db and sampled at 80kHz-96kHz (not reproduced, SAMPLED!).

Of course. The maximum signal that can be accurately digitized is just under 1/2 of the sample rate. I don't know when you failed to learn this factoid as shown above, but I successfully learned it in the late 1960s.

Here's another key point that you don't seem to understand. Information at -120 dB or 80 dB below that of normal audio signals is simply inaudible.
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If you noticed, the rainbow-looking bar on the right side doesn't correspond directly with the graph itself. It just shows what color corresponds with which rate.

Of course. I've have possibly been reading spectrograms since before your father was born. ;-)
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post #189 of 235 Old 10-22-2013, 09:26 AM
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Originally Posted by andyc56 View Post

Quote:
Originally Posted by grigorianvlad View Post

No, those are not ultrasonics. The frequency there isnt a frequency response. It is a resolution of recording (kind of similar to kBps or bitrate of MP3s, but not really), the density of it. How much data is cramped into each millisecond of recording.

You have absolutely no clue WTF you are talking about.

Agreed.
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post #190 of 235 Old 10-22-2013, 09:27 AM - Thread Starter
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Originally Posted by arnyk View Post


Of course. I've have possibly been reading spectrograms since before your father was born. ;-)

Since 1918? biggrin.gif
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post #191 of 235 Old 10-22-2013, 10:27 AM - Thread Starter
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Lets talk like responsible adults that we (most likely) are. I am sure you have had a lot of practice since 1918.
We agree on the theory behind it, but disagree on what we see in the graphs.
You are saying the graphs are showing frequency response. I am saying this is sample rate that we see.
This is easy to settle. Let me reach out to the makers of this software and ask them. They know for sure.
What speaks in your favor - and I just noticed it - is that the graphs for Studio Master top at 96kHz, which if we multiple by 2 , we get 192kHz exactly. So, this is probably the frequency response unless there was nothing above that recorded.
But lets see what the makers say.
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post #192 of 235 Old 10-22-2013, 10:59 AM
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You are saying the graphs are showing frequency response. I am saying this is sample rate that we see.
This is easy to settle. Let me reach out to the makers of this software and ask them.
If you have to ask the makers of the software what the graphs mean, then you shouldn't be arguing with people here who are telling you what the graphs mean.

If you can't explain how it works, you can't say it doesn't.—The High-End Creed

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post #193 of 235 Old 10-22-2013, 11:54 AM
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Originally Posted by mcnarus View Post

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You are saying the graphs are showing frequency response. I am saying this is sample rate that we see.
This is easy to settle. Let me reach out to the makers of this software and ask them.
If you have to ask the makers of the software what the graphs mean, then you shouldn't be arguing with people here who are telling you what the graphs mean.

Thanks.

Let's look at the graph:



In the middle of the page it says that the signal is sampled at 192KHz, 24 bits.

The labels on the Y Axis to the left go from 0 Hz to 96 KHz.

Some of us (maybe about 90% or more of those reading this thread) know from digital first principles that the highest frequency that a 192 KHz sample rate can accurately digitize is 96 KHz. Two articles from Wikipedia were just posted essentially saying that.

Why would one need to ask the vendor if one knows digital first principles and how graphs are generally drawn and labelled?

This is a good example of why the really smart people that I know stay away from consumer forums - having to take abuse from ...
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post #194 of 235 Old 10-22-2013, 12:28 PM - Thread Starter
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Originally Posted by arnyk View Post


This is a good example of why the really smart people that I know stay away from consumer forums - having to take abuse from ...

I dont care about their style. Its their weakness after all, ArnyK. It is actually rather amusing seeing grown ups imitating drill instructors. This forum isn't a boot camp.
I do care about the truth - whether it is on my side or not. Lets see what it is.
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post #195 of 235 Old 10-22-2013, 12:39 PM
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Let's look at the graph:
LL
Yes, let's. That looks to me like something sampled at 96 kHz, not 192 kHz.

If you can't explain how it works, you can't say it doesn't.—The High-End Creed

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post #196 of 235 Old 10-22-2013, 01:03 PM
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Quote:
Originally Posted by grigorianvlad View Post

Quote:
Originally Posted by arnyk View Post


This is a good example of why the really smart people that I know stay away from consumer forums - having to take abuse from ...

I don't care about their style. Its their weakness

It's not style, its the frustration.
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after all, ArnyK. It is actually rather amusing seeing people act as drill instructors. This forum isn't a boot camp.

It would appear that you've never actually been to a real boot camp. Army, Ft Knox, 1966. However I had a few Engineering Profs who would have fit right in. ;-)
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I do care about the truth - whether it is on my side or not. Lets see what it is.

The truth is sitting right before you, in the Wikipedia articles, one of which I believe you cited.

If something that clear does not convince you, I don't see how the software vendor's people can help.

If watching you get humiliated was fun for me, then this would be it. It's not...
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post #197 of 235 Old 10-22-2013, 01:07 PM - Thread Starter
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Originally Posted by arnyk View Post

It's not style, its the frustration.
It would appear that you've never actually been to a real boot camp. Army, Ft Knox, 1966. However I had a few Engineering Profs who would have fit right in. ;-)
The truth is sitting right before you, in the Wikipedia articles, one of which I believe you cited.

If something that clear does not convince you, I don't see how the software vendor's people can help.

If watching you get humiliated was fun for me, then this would be it. It's not...

No problem. Enjoy, if you can.
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post #198 of 235 Old 10-22-2013, 03:49 PM
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Originally Posted by mcnarus View Post

Yes, let's. That looks to me like something sampled at 96 kHz, not 192 kHz.

Or, the levels above about 50 kH is below -120dB and will not show? But in either case, I really doubt that those ultrasonics are really musical contents.
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post #199 of 235 Old 10-22-2013, 04:46 PM - Thread Starter
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Originally Posted by CharlesJ View Post

Or, the levels above about 50 kH is below -120dB and will not show? But in either case, I really doubt that those ultrasonics are really musical contents.

Well, the software developer of Spek has spoken and I am devastated to report that I had managed to make a fool of myself once again. True, I had "no idea WTF I was taking about". Thank you, ArnyK, AndyC, and Mcnarus for pointing that out.
Quote:
Hi Vlad,

A good description is on the [wikipedia page][0], a spectrogram can
indeed be thought as a series of frequency responses over time. The
vertical axis is the signal frequency and the color intensity
corresponds to the [dBFS][1] level of the signal at the given
frequency and time. The sampling rate is constant and the max
frequency is always half of it because of the [sampling theorem][2].

Hope this clarifies things, let me know if it doesn't.

Cheers,
Alex

So, CharlesJ, sorry for the error. it was not my intention to deceive you. The only reason I can give you is that I ran a search for software to analyze sampling, which brought me to Spek. So, I assumed it was sampling I saw and they both marked as Hz. Later I noticed that the graph topped at 96kHz and therefore was a frequency (1/2 of sampling rate of 192kHz), but I still wasn't convinced.

Then ArnyK, AndyC, and Mcnarus tried to set me straight, but I refused to listen until I corresponded with the software maker.

Glad the truth came forth and everybody had their fun (me including).

Now let me figure out how to make a 192kHz 24bit vs CD vs MP3 blind test work. So far I just burned them to a BluRay in 48k 24 bit and listened. There is an audible difference, of course, between the MP3 and Studio Master. But the difference between CD and SM is so subtle that I doubt it will be noticeable in a blind test. Ethan is probably right.

So far some components I can configure to run in 192K, some I cant. Let me talk to some experts and see what can be done. Testing in 48k is unfair.

Thanks again.
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post #200 of 235 Old 10-22-2013, 05:13 PM
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So far some components I can configure to run in 192K, some I cant. Let me talk to some experts and see what can be done. Testing in 48k is unfair.
So start by testing CD vs. 192 kbps. If you can't tell them apart (and I'd bet against you), there's no point in testing 192kHz.

If you can't explain how it works, you can't say it doesn't.—The High-End Creed

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post #201 of 235 Old 10-22-2013, 05:18 PM - Thread Starter
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Originally Posted by mcnarus View Post

So start by testing CD vs. 192 kbps. If you can't tell them apart (and I'd bet against you), there's no point in testing 192kHz.

No, that wouldn't work. As I stated before my PC sound (via HDMI to the AVR) is worse than Bluray. It sounds a bit flat. So if there is a difference between the sources it will not be heard. The test has to be perfect.
Wait, does AirPlay play 192khz 24bit WAVs? That will take care of the problem.
Checking.
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post #202 of 235 Old 10-22-2013, 05:36 PM - Thread Starter
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No, AirPlay can't see any of the 3.
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post #203 of 235 Old 10-22-2013, 07:09 PM
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As I stated before my PC sound (via HDMI to the AVR) is worse than Bluray. It sounds a bit flat.
No, it doesn't. If you think that, the first thing you need to do is a blind test of that, which will show you that you're wrong.

If you can't explain how it works, you can't say it doesn't.—The High-End Creed

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post #204 of 235 Old 10-22-2013, 07:26 PM - Thread Starter
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Originally Posted by mcnarus View Post

No, it doesn't. If you think that, the first thing you need to do is a blind test of that, which will show you that you're wrong.

I dont understand. Are you telling me which equipment of mine sounds flat and which doesn't? Do you know what I have at all? Do you know when the problem occurred first in which equipment? How fast or slow it progressed over what period of time? Do you even know the extend of the problem with PC => HDMI => AVR sound?

Again, the test in 48KHz is not a perfect test. 192kHz 24bit is.
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post #205 of 235 Old 10-22-2013, 08:38 PM - Thread Starter
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Originally Posted by mcnarus View Post

No, it doesn't. If you think that, the first thing you need to do is a blind test of that, which will show you that you're wrong.

You are yanking my chain, aren't you, Mcnarus? Trying to send me on a wild goose chase to entertain you? frown.gif
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post #206 of 235 Old 10-23-2013, 08:15 AM
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I dont understand. Are you telling me which equipment of mine sounds flat and which doesn't? Do you know what I have at all? Do you know when the problem occurred first in which equipment? How fast or slow it progressed over what period of time? Do you even know the extend of the problem with PC => HDMI => AVR sound?
What I'm telling you is that two identical digital signals fed to the same AVR must sound identical. If you think they don't, then either something is very wrong (as in, broken), or you are imagining it. There is no third alternative. Try a blind test, and you will see.

If you can't explain how it works, you can't say it doesn't.—The High-End Creed

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post #207 of 235 Old 10-23-2013, 08:43 AM - Thread Starter
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Thank you, Mcnarus. But the signals are NOT identical compared to the same WAVs burned to a BD and played in BD player through the same AVR as PC connected to. That is what I have been saying: PC sounds equally worse for all files. The BD sounds great for all files. The test has to be done on a system that is capable of the best sound in my house. And the PC isnt one of them. I am not sure if something is broken there, that is possible.
But doing a test in the PC is similar to doing a drag race between 3 exotic cars with parking claps on all 4 wheels. Its a gag, not a race. I am sure it will be very entertaining (lots of smoke, blown engines, flaming transmissions, a cool mil down the drain in 30 seconds or less), but no objective value whatsoever.
So, I would rather fix what I have to make sure 192kHz is given a fair chance. The graphs show there is something in 192kHz 24bit. Can we hear it, though?
I read somewhere yesterday that some studio played to musicians their own freshly recorded soundtrack in CD and Studio Master and most of them were able to tell one from the other, preferring SM for its "airiness". There was nothing about methodology, so I cannot speculate whether it was a test, rather than an observation.
Take care and thank you.
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post #208 of 235 Old 10-23-2013, 09:48 AM
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Quote:
Originally Posted by CharlesJ View Post

Quote:
Originally Posted by mcnarus View Post

Yes, let's. That looks to me like something sampled at 96 kHz, not 192 kHz.

Or, the levels above about 50 kH is below -120dB and will not show? But in either case, I really doubt that those ultrasonics are really musical contents.

Musical instruments can easily create harmonics above 50 KHz:

http://www.cco.caltech.edu/~boyk/spectra/spectra.htm



The problem isn't finding instruments that create harmonics that high. The problem is finding human ears that respond reliably that high - they don't exist!

There are other practical problems as well.

Loudspeakers and headphones that work above 50 KHz are rare.

The speakers I've worked with that do have appreciable response above even just 25 KHz have very poor off-axis response at that frequency. Move a few degrees off-axis and their response > 25 KHz falls off rapidly.



Note that the red line (response at 45 degrees off axis) falls like a stone starting around 7 KHz. A similar thing starts at 22.5 degrees starting at 12 KHz. I'll bet that you don't have tweeters comparable to these special ring radiators in your home speakers.

Sound at those high frequencies looses intensity rapidly as it passes through the air.

http://www.sengpielaudio.com/calculator-distance.htm

A more serious problem is that the response of most recording microphones falls off rapidly above 20 KHz. Heck, many start rolling off rapidly at 15 KHz, and they have more serious problems off-axis, just like speakers. If you read the details in the article I cited above, the author used a 1/4" measurement microphone that is rarely if ever used for making practical recordings, partially because it is omnidirectional and partially because it has poor dynamic range (noisy!).
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post #209 of 235 Old 10-23-2013, 09:54 AM
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Quote:
Originally Posted by arnyk View Post

Musical instruments can easily create harmonics above 50 KHz:

Yes, and jingling keys is a common test for microphones. I did that years ago with a Telefunken U47 into a Hewlett-Packard real-time analyzer. I was surprised to see substantial content all the way up to the 50 KHz limit of the analyzer.

--Ethan

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post #210 of 235 Old 10-23-2013, 09:58 AM - Thread Starter
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I managed to upconvert all 3 test files to 192kHz 24 bit and burn them to a BD .
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