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Launch of Pono Studio Headphones
Old 27th March 2014
  #1921
Gear Nut
 

Thanks for the encouragement theblue1. However, you are doing nothing to deal with my panic about my ADC!!! WTF?!?

Here is a plot of the sinewave using an m-audio usb audio interface box I have lying around. And indeed it looks really good. ($200 ADC)

sin-2_5khz_44_1ksr_m-audio.wav

I am so depressed. At least Mytek is right across the river in Brooklyn, maybe I get to go see the factory!
Old 27th March 2014
  #1922
Gear Nut
 

Quote:
Originally Posted by BasHermus View Post
It sounds as if the square wave was not properly low-passed before being converted to digital.

In that case, this is what should be expected. Even with a 2.5 kHz signal (given that a square wave is the sum of an infinite number of higher order harmonic sine-waves of the root of the wave (in this case 2.5 kHz)).

No even the sine wave has other stuff in it on the Mytek. So something is up. I played a sinewave through with the real time playback enabled and as I vary the frequency there are ALL KINDS of subtones that wander in the opposite or same direction as the frequency I am shifting to. Kind of like rayguns in outer space.
Old 27th March 2014
  #1923
Gear Maniac
 
BasHermus's Avatar
 

Hmmmm... in that case I have got no clue.

You could use it as an effect (albeit a nasty sounding one).
Old 27th March 2014
  #1924
Gear Nut
 

Quote:
Originally Posted by bogosort View Post
Agreed. And look on the bright side: at least you found the weak spot in your chain. I wonder how many other people are hearing "night and day" differences between 44.1 and higher rates simply because their converters suck at 44.1.

But you were right: you were definitely hearing something!
And listening straight to the signal generator on my headphones still reveals the difference between the square wave and the sine wave at 10kHz.

Maybe you can use your ADC while mine is in the shop and post 10kHz sine and square at 96khz for all to hear? We at least have that possibility.
Old 27th March 2014
  #1925
Quote:
Originally Posted by jkorten View Post
Thanks for the encouragement theblue1. However, you are doing nothing to deal with my panic about my ADC!!! WTF?!?

Here is a plot of the sinewave using an m-audio usb audio interface box I have lying around. And indeed it looks really good. ($200 ADC)

Attachment 391527

I am so depressed. At least Mytek is right across the river in Brooklyn, maybe I get to go see the factory!
Mmm... if it was a straight trade and the M-Audio is essentially doing fine in the same circumstances, I admit, that doesn't seem to be a good sign. I was hoping for a procedural error, of course. Always nicer to slap yourself on the forehead because you made some silly little mistake than because your gear is misbehaving.

Good luck on this. At least you're on the road to getting it straightened out. And I feel confident you will.
Old 27th March 2014
  #1926
Gear Nut
 

Quote:
Originally Posted by theblue1 View Post
Mmm... if it was a straight trade and the M-Audio is essentially doing fine in the same circumstances, I admit, that doesn't seem to be a good sign. I was hoping for a procedural error, of course. Always nicer to slap yourself on the forehead because you made some silly little mistake than because your gear is misbehaving.

Good luck on this. At least you're on the road to getting it straightened out. And I feel confident you will.
They will soon tell me how much it will cost. I can't imagine anything but a complete motherboard swap. Oh the pain... the pain. (First world suffering.) I just bought the thing a bit over a year ago too. So of course warranty is expired.
Old 27th March 2014
  #1927
Yeah... your big view perspective is a healthy one, I think. But I nonetheless feel your first world pain.
Old 27th March 2014
  #1928
Gear Guru
 
UnderTow's Avatar
Quote:
Originally Posted by jkorten View Post
Thanks for the encouragement theblue1. However, you are doing nothing to deal with my panic about my ADC!!! WTF?!?

Here is a plot of the sinewave using an m-audio usb audio interface box I have lying around. And indeed it looks really good. ($200 ADC)

Attachment 391527

I am so depressed. At least Mytek is right across the river in Brooklyn, maybe I get to go see the factory!
Yikes! Now I understand your comments. Mytek is supposed to have a good reputation so I suspect something is wrong with your specific converter. Is it still under guarantee? (EDIT: Just saw your later post. Bummer). Good luck with this!

Alistair
Old 27th March 2014
  #1929
Lives for gear
 
bogosort's Avatar
Quote:
Originally Posted by jkorten View Post
And listening straight to the signal generator on my headphones still reveals the difference between the square wave and the sine wave at 10kHz.

Maybe you can use your ADC while mine is in the shop and post 10kHz sine and square at 96khz for all to hear? We at least have that possibility.
In this post https://www.gearslutz.com/board/9981894-post1917.html I uploaded two 10k square waves, one at 44.1 and one at 96. The 44.1 version is essentially a sine wave, because there are no other frequencies other than the fundamental.

With the RME at 96k, I tried to ABX the two files (after applying a tiny bit of ReplayGain) through both my speakers and my headphones. After a couple of trials in each I gave up because I was guessing.
Old 27th March 2014
  #1930
Gear Guru
 
UnderTow's Avatar
Btw, what OS are you on and how do you have Audacity setup? I can lock the sample rate on my converters and then switch the sample rate externally. If I then select the "Default Windows device" or something like that as a driver, the signal goes through the Windows realtime SRC. This is very much audible. Maybe you are also just suffering from the Windows (or MacOS) realtime SRC?

Alistair
Old 27th March 2014
  #1931
Lives for gear
 
bogosort's Avatar
Quote:
Originally Posted by UnderTow View Post
Btw, what OS are you on and how do you have Audacity setup? I can lock the sample rate on my converters and then switch the sample rate externally. If I then select the "Default Windows device" or something like that as a driver, the signal goes through the Windows realtime SRC. This is very much audible. Maybe you are also just suffering from the Windows (or MacOS) realtime SRC?
If that were the case, I'd expect the 192k version to be messed up, not the 44.1 sine (because no SRC would be needed). Or am I missing something?
Old 27th March 2014
  #1932
Gear Guru
 
UnderTow's Avatar
Quote:
Originally Posted by bogosort View Post
If that were the case, I'd expect the 192k version to be messed up, not the 44.1 sine (because no SRC would be needed). Or am I missing something?
It depends what the sample rate target is. For instance, I can set my interface to 192Khz then lock it and play something back at 44.1Khz. The 44.1 Khz then gets SRCed to 192 Khz. I can do it the other way round too.

EDIT: To be clear, locking the sample rate is as simple as having an audio application open that locks the interface. That could be Winamp (During playback or pause. Not when it is stopped), Pro Tools or simply having a webpage open that has audio (YouTube, SoundCloud, anything...). Some applications like Cubase don't lock the interface.

Alistair
Old 27th March 2014
  #1933
Quote:
Originally Posted by UnderTow View Post
It depends what the sample rate target is. For instance, I can set my interface to 192Khz then lock it and play something back at 44.1Khz. The 44.1 Khz then gets SRCed to 192 Khz. I can do it the other way round too.

EDIT: To be clear, locking the sample rate is as simple as having an audio application open that locks the interface. That could be Winamp (During playback or pause. Not when it is stopped), Pro Tools or simply having a webpage open that has audio (YouTube, SoundCloud, anything...). Some applications like Cubase don't lock the interface.

Alistair
Cubase doesn't lock the interface's SR because they expect it to be used with ASIO drivers (which, as I recall, don't support multiple simultaneous access), though, yeah?

(I'm not a Cubase guy.)
Old 27th March 2014
  #1934
Lives for gear
 
nuthinupmysleeve's Avatar
 

Quote:
Originally Posted by jkorten View Post
I am so depressed. At least Mytek is right across the river in Brooklyn, maybe I get to go see the factory!
Dude, that really SUCKS... let us know how it goes. Very frustrating!!
Old 27th March 2014
  #1935
Gear Nut
 

Not the ADC it turns out - the interface

So the ADC turns out to be working. While on a conf call it occured to me to check the interface that allows me to capture AES to USB or Firewire. Fortunately I have two methods - one is from Yellowtec the PUC2 which comes in by my USB ports. The other is the Mytek 192DAC which allows the AES to be captured via firewire. This last interface is what I was using earlier and this is where the errors were being inserted. I don't know how yet. But I resampled all using the PUC2 and they are fine. Here they are:

sin-10khz_at_44ksr.wav

square-10khz_at_44ksr.wav

sine-10khz_at_192ksr.wav

square-10khz_at_192ksr.wav


Then for completeness the 2.5khz square and sine waves from earlier - the point here being - can you hear more of the 2.5khz square wave at 192k than you can at 44.1k sample rates? (sine waves are for quality check that bogosort was SO KIND to point out! )

square-2_5khz_at_192ksr.wav

square-2_5khz_at_44ksr.wav

sine-2_5khz_at_44ksr.wav

What an emotional roller coaster today has been!
Old 27th March 2014
  #1936
Lives for gear
 
bogosort's Avatar
Quote:
Originally Posted by jkorten View Post
What an emotional roller coaster today has been!
Maybe it's not done yet? The 10 kHz square at 44.1 looks great -- congrats on getting that sorted out. But the 10k square at 192 is missing all its overtones, which at 192k S/s should be at 30k, 50k, 70k, and 90k.

Looks like you have a LPF somewhere. What's the bandwidth of your function generator?
Old 27th March 2014
  #1937
Gear Nut
 

Thanks buddy!

wrong sample rate - re-recording and uploading correct sample rate versions in 5
Old 27th March 2014
  #1938
Gear Guru
 
UnderTow's Avatar
Quote:
Originally Posted by bogosort View Post
But the 10k square at 192 is missing all its overtones, which at 192k S/s should be at 30k, 50k, 70k, and 90k.
Maybe because it is a 44.1 Khz file.

Alistair
Old 27th March 2014
  #1939
Gear Nut
 

Quote:
Originally Posted by bogosort View Post
Maybe it's not done yet? The 10 kHz square at 44.1 looks great -- congrats on getting that sorted out. But the 10k square at 192 is missing all its overtones, which at 192k S/s should be at 30k, 50k, 70k, and 90k.

Looks like you have a LPF somewhere. What's the bandwidth of your function generator?
Now fixed.
Old 27th March 2014
  #1940
Gear Guru
 
UnderTow's Avatar
There is still something strange going on. All your 2.5 Khz tone recordings have a tone at 5166 Hz. It is there in both sample rates and in both the square and sine recording. There are also harmonics of this tone.

All the 10 Khz recordings have a tone at 19890 Hz.

It is all a bit strange. Maybe it is coming from your tone generator but maybe it is something else...

Alistair
Old 27th March 2014
  #1941
I had a lightpipe cable get crimped and act all wack back in the day. But it wasn't anything like this, for sure.
Old 27th March 2014
  #1942
Quote:
Originally Posted by UnderTow View Post
Let's keep things simple or at least test them one at a time: Stick to 24 bit and just compare the sample rates. Also, make sure you use a quality SRC, NOT the one built into your DAW. I suggest the iZotope SRC or the SoX one (It is free).

Alistair
I will try SoX as I don't have the budget for iZotope SRC.

I dont understand what you mean by stick to 24-bit. If an increase to 44.1/24 produced audible differences, wouldn't that prove CD quality resolution can be improved upon?

The whole argument is that 44.1/16 is "enough" mathematically speaking... this test is to determine whether we can accurately differentiate CD quality audio and high-resolution (up to 192/24) audio. I see no point in down-sampling in between these two points.

from my understanding the science explained in this thread claims that any differences above 44.1/16 is inaudible to the human ear, making 192/24 and anywhere in between overkill.

several users have mentioned that 48/24 and even 96/24 creates audible differences, others have denied this is possible based on science and math. regardless of the in-between resolutions, i want to see if there are audible benefits to a delivery format exceeding CD Quality Resolution.

this test will at least show the merits (or demerits) of hi-res audio
Old 27th March 2014
  #1943
Gear Guru
 
UnderTow's Avatar
Quote:
Originally Posted by orenradio View Post
I will try SoX as I don't have the budget for iZotope SRC.

I dont understand what you mean by stick to 24-bit. If an increase to 44.1/24 produced audible differences, wouldn't that prove CD quality resolution can be improved upon?
I am suggesting we test it one step at a time. First let's see if the sample rate makes a difference. Then we can test bit depth-reduction. (The format conversion would also do it in two steps).

Quote:
The whole argument is that 44.1/16 is "enough" mathematically speaking... this test is to determine whether we can accurately differentiate CD quality audio and high-resolution (up to 192/24) audio. I see no point in down-sampling in between these two points.
Just to be clear, it isn't down-sampling. It is bit-depth reduction. And yes we can test it but it should be one step at a time. One reason being: We can use different dither types for the bit-depth conversion. Actually, we can also use many different settings and converters for the sample rate conversion.

I suggest SoX in VHQ Linear Phase mode.

Alistair
Old 27th March 2014
  #1944
Glad you are getting that worked out jkorten. Gear issues are such a horrible nightmare, especially digital/computer related ones. For a month a while back I was dealing with intermittent pops and clicks, spent hours trouble shooting, sent gear in for testing and nothing helped. It turned out to be a v1 mc control, something with the Ethernet and driver was causing my system to stall for a fraction of second causing the clicks.
Old 27th March 2014
  #1945
Lives for gear
 
bogosort's Avatar
Quote:
Originally Posted by jkorten View Post
Now fixed.
There we go, all the expected harmonics. The amplitude deviations from the expected 1/(2n+1) pattern are probably resonance issues in your generator.

Anyway, given that the lowest non-fundamental tone in that file is distortion at 20k (80 dB down), I submit that the only way one could hear a difference between this and the 44.1k version is if the speakers poop the bed when presented with ultrasonic frequencies.

Consider this: Even if the ear itself was nonlinear with ultrasonics (and it isn't, according to Paul Frindle's research), the difference tones all line up with the signal (30k - 10k = 20k, etc.), so there'd be no new in-band information to hear.
Old 27th March 2014
  #1946
Gear Nut
 

Quote:
Originally Posted by bogosort View Post
There we go, all the expected harmonics. The amplitude deviations from the expected 1/(2n+1) pattern are probably resonance issues in your generator.

Anyway, given that the lowest non-fundamental tone in that file is distortion at 20k (80 dB down), I submit that the only way one could hear a difference between this and the 44.1k version is if the speakers poop the bed when presented with ultrasonic frequencies.

Consider this: Even if the ear itself was nonlinear with ultrasonics (and it isn't, according to Paul Frindle's research), the difference tones all line up with the signal (30k - 10k = 20k, etc.), so there'd be no new in-band information to hear.

I admit - my generator, which cost $200 in 1986 is no match for yours.

The relative strengths of the harmonics are totally different though, and I'm not sure of the utility of speaking of our hearing in the frequency domain. We don't do an FFT, we have hair cells in a continuous fluid column that are picking up these signals. I am also going to guess that there is interaction going on between harmonics etc. at that level as well.

But again - I go back to my perception. If I can hear the difference, the difference is important to me. If I cannot, then it wouldn't. But it is! So I care.

The perception issues need to be sorted out by acoustics experts who can help out here.
Old 27th March 2014
  #1947
Gear Nut
 

Quote:
Originally Posted by UnderTow View Post
I am suggesting we test it one step at a time. First let's see if the sample rate makes a difference. Then we can test bit depth-reduction. (The format conversion would also do it in two steps).



Just to be clear, it isn't down-sampling. It is bit-depth reduction. And yes we can test it but it should be one step at a time. One reason being: We can use different dither types for the bit-depth conversion. Actually, we can also use many different settings and converters for the sample rate conversion.

I suggest SoX in VHQ Linear Phase mode.

Alistair
Alistair - the files I put up are all 16 bit. It appears Gearslutz doesn't allow flac files so I had to convert them all to wav format at 16 bit depth.
Old 27th March 2014
  #1948
Gear Nut
 

Quote:
Originally Posted by jasonwagner View Post
Glad you are getting that worked out jkorten. Gear issues are such a horrible nightmare, especially digital/computer related ones. For a month a while back I was dealing with intermittent pops and clicks, spent hours trouble shooting, sent gear in for testing and nothing helped. It turned out to be a v1 mc control, something with the Ethernet and driver was causing my system to stall for a fraction of second causing the clicks.
Wow. I've taken to disabling all non-microsoft services when recording. Have you seen the recommendations at Sweetwater for how to optimize a computer for DAW work? Very helpful. Disable all networking before recording would be the lesson to learn from your nightmare. Yikes.
Old 27th March 2014
  #1949
Gear Nut
 

Quote:
Originally Posted by UnderTow View Post
There is still something strange going on. All your 2.5 Khz tone recordings have a tone at 5166 Hz. It is there in both sample rates and in both the square and sine recording. There are also harmonics of this tone.

All the 10 Khz recordings have a tone at 19890 Hz.

It is all a bit strange. Maybe it is coming from your tone generator but maybe it is something else...

Alistair
Please contribute to my new signal generator fund - and I will provide distortion free recordings of sinewaves and squarewaves!

None of this will affect your ability to tell the difference between the 192 version and the 44.1 version as they are the same signal being sampled. Can you tell the difference?

Can you tell the difference between the sinewave and the squarewave at 10kHz at 192K?

J
Old 27th March 2014
  #1950
Quote:
Originally Posted by jkorten View Post
Wow. I've taken to disabling all non-microsoft services when recording. Have you seen the recommendations at Sweetwater for how to optimize a computer for DAW work? Very helpful. Disable all networking before recording would be the lesson to learn from your nightmare. Yikes.
This was on a mac, which is usually pretty ok right out of the box, at least with what I use, Logic, UAD and Apogee stuff.

The euphonix controller had it's own program that was constantly running, which I had tested by not installing during one of a few clean wipes and reinstalls but it wouldn't start acting up until I was in a big session. For my testing after reinstall I was just trying a new empty session, which I know now was a mistake. Troubleshooting is a skill all in itself I have learned. I got rid of that thing as soon as I identified it as a problem, I was so damn mad.
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