Penknife in the hands of a skilled surgeon is far better than a very sharp lancet.
Перочинный ножичек в руках искусного хирурга далеко лучше иного преострого ланцета.
Kozma Prutkov, Fruits of Reflection (1853-1854).
Козьма Прутков, Плоды раздумья: Мысли и афоризмы.
Free HiRes audio files (audiophile reference recordings) are available for download on the 2L website.
HiRes Download - test bench
http://www.2l.no/hires/index.html
To download audio files username: 2L and password: 2L is requested.
We invite you to join us in this evaluation of future consumer delivery formats. FLAC is a lossless encoding of WAV-files derived directly from our production original used for the SACD and Pure Audio Blu-ray. All resolutions and encodings are derived from the same original DXD source files. Please send us an e-mail and share your experience on your practical experience with these file formats. Enjoy the music!
WARNING: These HiRes audio files are not supposed to be studied by the deaf, blind, and the stupid.
If ALSA/PulseAudio users do not hear the difference, they may discuss their problems on Ubuntu/Arch Linux forums.
There are two sorts of HiRes audio files available for download on the 2L website:
1. the original recordings,
2. the results of downsampling to different low quality formats, such as 24bit/96kHz and 24bit/192kHz
The DXD 24BIT 352.8kHz Waves are said to be recorded with PYRAMIX digital audio workstation http://www.lindberg.no/english/recording.htm
The original recordings, i.e. DXD Waves, are said to be converted to "digital crap" through the help of Weiss SARACON Sampling Rate Converter http://www.lindberg.no/english/editing.htm
First of all, we have to try a nice piece of anti-digital art:
W.A.Mozart: Violin concerto in D major (KV 218) - Allegro 9:24
Performers: Marianne Thorsen, TrondheimSolistene, Øyvind Gimse
From the album: MOZART (2L38SACD)
It might be obvious that Morten Lindberg selected special files for "evaluation of future consumer delivery formats".
Mozart's "Violin concerto in D major" proved to be the hardest nut to crack for any resampler. It is the first in the list, and there is a reason for this.
NOTE: The deaf, blind, and the stupid may not notice the difference.
Step 1: Download the files (2L-038-SACD):
[FLAC 24bit 96kHz] Mozart - Violin concerto in D major - Allegro 2L38_01_96kHz.flac
http://www.lindberg.no/hires/test/2L38_01_96kHz.flac
[WAV DXD 24bit 352.8kHz] Mozart - Violin concerto in D major (KV 218) - Allegro Stereo WAV DXD 24BIT 352.8kHz 2L38_01_DXD.wav
http://www.lindberg.no/hires/test/2L38_01_DXD.zip
Step 2: Rename them as follows:
01_2L_Mozart_24bit_96kHz_Weiss_SARACON_SRC.flac
01_2L_Mozart_24bit_352.8kHz.wav
Thus, you have the samples for "evaluation":
01_2L_Mozart_24bit_352.8kHz.wav is the original recording.
01_2L_Mozart_24bit_96kHz_Weiss_SARACON_SRC.flac seems to be an example of "future consumer delivery formats", a kind of "digital crap of the future".
Morten Lindberg tends to claim that downsampling produces "degeneration":
Comparing them in our studio we find only subtle differences from DXD (24BIT/352.8kHz) down to 192kHz and 96kHz. The obvious degeneration is from 96kHz down to 48kHz. http://morten.lindberg.no/19537/
It is not completely true, because "denaturation of sound" is already obvious on sonograms of 96kHz FLACs.
It is obvious on sonograms and it is audible, of course. Otherwise, 192kHz FLACs would not make much sense.
NOTE: The deaf, blind, and the stupid may not notice the difference.
Before we dig deeper into the nature of crap, a word about the proper tools. Of course, every scientific research requires certain tools to succeed, not just tools but relevant tools. There are, perhaps, exact scientific instruments, which might be utilized for the purpose. If they are missing, one may try what is available. There is a kind of penknife, with which to dig into the crap: SoX, "the Swiss Army knife of sound processing programs" http://sox.sourceforge.net/ Since SoX is free, "open source", and "cross-platform", it can be used for education purposes. Although, of course, it might obvious that the deaf lunatics are not able to learn anything, except for "religious knowledge", or Cargo Cult Science http://calteches.library.caltech.edu/51/2/CargoCult.pdf That is why they constantly fail to learn from experience. The story of PulseAudio proves this point.
Keep in mind that sonograms represent Fourier series rather then "frequencies". If huge distortions are noticeable on sonograms, it means that the particular resampler, such as Weiss SARACON Sampling Rate Converter, or other sort of "software crap" (softcrap), failed miserably.
The distortions of "digital crap" inside 96kHz FLACs are so huge that they can be easily detected with SoX sonograms.
Since the distortions had been produced by the softcrap resampler, they look similar to overtones, in the sense that they are somehow localized inside certain bands:
35kHz - 40kHz huge distortions
29kHz - 32kHz huge distortions
14kHz - 20kHz huge distortions
We have already observed a similar phenomenon with the Audacity/Nyquist resampler.
It might be natural to presume that there are big distortions below 14kHz, which might not be easily detected with SoX sonograms. There are likely to be big distortions, and there are obvious distortions below 14kHz. Although, of course, the deaf, blind, and the stupid may fail to notice them.
Step 3: Apply the secret esoteric command:
Code: Select all
$ sox -S "01_2L_Mozart_24bit_96kHz_Weiss_SARACON_SRC.flac" -n remix 2 spectrogram -S 00:05 -d 00:03.1 -c "Created by SoX FILE: 01_2L_Mozart_24bit_96kHz_Weiss_SARACON_SRC.flac" -o "sonogram_01_2L_Mozart_24bit_96kHz_Weiss_SARACON_SRC.png" stat
This will produce a sonogram: sonogram_01_2L_Mozart_24bit_96kHz_Weiss_SARACON_SRC.png
The sonogram shows information only from the second (right) channel, and of 3.1 seconds of audio starting from 5 seconds in.
Step 4: Crop the picture with a magic command:
Code: Select all
$ convert -crop 944x576+0+15 *96kHz_Weiss_SARACON_SRC.png 48kHz_sonogram_01_2L_Mozart_24bit_96kHz_Weiss_SARACON_SRC.png
Code: Select all
$ pacman -Qo convert
/usr/bin/convert is owned by imagemagick 6.7.2.8-1
The audible range of frequencies is said to be 20Hz to 20kHz http://en.wikipedia.org/wiki/Hearing_range
You may want to zoom into this range to see the audible distortions of "genuine digital crap".
Step 5: Zoom into the audible range of frequencies [20Hz - 20kHz]:
Code: Select all
$ sox -S "01_2L_Mozart_24bit_96kHz_Weiss_SARACON_SRC.flac" -n remix 2 spectrogram -Y 1100 -S 00:05 -d 00:03.1 -c "Created by SoX FILE: 01_2L_Mozart_24bit_96kHz_Weiss_SARACON_SRC.flac" -o "sonogram_01_2L_Mozart_24bit_96kHz_Weiss_SARACON_SRC_2.png" stat
Code: Select all
$ convert -crop 944x576+0+527 *96kHz_Weiss_SARACON_SRC_2.png 24kHz_sonogram_01_2L_Mozart_24bit_96kHz_Weiss_SARACON_SRC_2.png
Step 6: Build sonograms of the original DXD Wave with the following commands:
Code: Select all
$ sox -S "01_2L_Mozart_24bit_352.8kHz.wav" -n remix 2 spectrogram -Y 1100 -S 00:05 -d 00:03.1 -c "Created by SoX FILE: 01_2L_Mozart_24bit_352.8kHz.wav" -o "sonogram_01_2L_Mozart_24bit_352.8kHz.png" stat
Code: Select all
$ convert -crop 944x576+0+527 *352.8kHz.png 90kHz_sonogram_01_2L_Mozart_24bit_352.8kHz.png
Code: Select all
$ sox -S "01_2L_Mozart_24bit_352.8kHz.wav" -n remix 2 spectrogram -Y 2050 -S 00:05 -d 00:03.1 -c "Created by SoX FILE: 01_2L_Mozart_24bit_352.8kHz.wav" -o "sonogram_01_2L_Mozart_24bit_352.8kHz_2.png" stat
Code: Select all
$ convert -crop 944x576+0+1551 *352.8kHz_2.png 44kHz_sonogram_01_2L_Mozart_24bit_352.8kHz_2.png
Step 7: Compare sonograms of "digital crap" and the original DXD Wave.
CONCLUSION: Mozart's "Violin Concerto no. 4 in D major" (KV 218) can be used in a "blind test" with deaf lunatics. Although, of course, they are not intelligent enough to accept an idea that they need to undergo a medical examination before it is too late.
Mozart's "Violin Concerto no. 4 in D major" (KV 218) can also be utilized for:
1. testing resamplers (e.g. GRC3 SRC);
2. testing audio systems and Sennheiser headphones.
Sennheiser HD 598 Headphones
Technical Data:
Frequency response 12 – 38500 Hz
THD, total harmonic distortion < 0.1 % (1 kHz/100 dB SPL)
http://www.sennheiser.co.uk/uk/home_en. ... nes_504633
NOTE: If you want to zoom into a sonogram, you may need to increase its resolution.
The official SoX manual is here: http://sox.sourceforge.net/sox.html
ImageMagick Tutorial is here: http://xahlee.org/img/imagemagic.html
The sonograms are in the Attachment (updated):
Code: Select all
48kHz_sonogram_01_2L_Mozart_24bit_96kHz_Weiss_SARACON_SRC.png
24kHz_sonogram_01_2L_Mozart_24bit_96kHz_Weiss_SARACON_SRC_2.png
44kHz_sonogram_01_2L_Mozart_24bit_352.8kHz_2.png
90kHz_sonogram_01_2L_Mozart_24bit_352.8kHz.png
NOTE: The deaf, blind, and the stupid may not need to study the sonograms.