Is 22kHz brickwall cut off audible?
Long term discussion about audibility of >20kHz content, filter slopes, hires, etc. …, so here is my 12 cents. There are 2 test files in 96/24 format, one of them is unmodified, the other one has sharp brickwall cut off at 21.9kHz, but no action below 21.9kHz. The files are located at
To play the files properly, one must be sure that the PC preserves 96kHz playback and does not re-sample down to 44.1kHz or 48kHz due to Windows sound settings. The best way is to use ASIO drivers or to check on DAC display, if it shows the sampling frequency.
If you are interested, please download and unzip the files and try if you can hear the difference and if possible, please also post your ABX test report to verify you were able or not to hear the difference. Please also feel free to use Paul's @pkane excellent Deltawave software that would show you how the files are matched and how they differ.
Following are several Deltawave screenshots of these files:
Original and brickwall spectra
The difference spectrum
Pkmetric of the test files
Report of file matching
And finally my ABX test report
16/20 total result
Have fun!
Long term discussion about audibility of >20kHz content, filter slopes, hires, etc. …, so here is my 12 cents. There are 2 test files in 96/24 format, one of them is unmodified, the other one has sharp brickwall cut off at 21.9kHz, but no action below 21.9kHz. The files are located at
To play the files properly, one must be sure that the PC preserves 96kHz playback and does not re-sample down to 44.1kHz or 48kHz due to Windows sound settings. The best way is to use ASIO drivers or to check on DAC display, if it shows the sampling frequency.
If you are interested, please download and unzip the files and try if you can hear the difference and if possible, please also post your ABX test report to verify you were able or not to hear the difference. Please also feel free to use Paul's @pkane excellent Deltawave software that would show you how the files are matched and how they differ.
Following are several Deltawave screenshots of these files:
Original and brickwall spectra
The difference spectrum
Pkmetric of the test files
Report of file matching
DeltaWave v1.0.70, 2022-07-10T22:29:04.5264509+02:00
Reference: BreakOn_1sh.wav[L] 5760000 samples 96000Hz 24bits, stereo, MD5=00
Comparison: BreakOn_3sh.wav[L] 5760000 samples 96000Hz 24bits, stereo, MD5=00
Settings:
Gain:True, Remove DC:True
Non-linear Gain EQ:False Non-linear Phase EQ: False
EQ FFT Size:65536, EQ Frequency Cut: 0Hz - 0Hz, EQ Threshold: -160dB
Correct Drift:True, Precision:30, Subsample Align:True
Non-Linear drift Correction:False
Upsample:False, Window:Hann
Spectrum Window:Kaiser10, Spectrum Size:262144
Spectrogram Window:Hann, Spectrogram Size:4096, Spectrogram Steps:2048
Filter Type:FIR, window:Hann, taps:8192, minimum phase=False
Dither:False
Trim Silence:False
Enable Simple Waveform Measurement: False
Discarding Reference: Start=0s, End=0s
Discarding Comparison: Start=0s, End=0s
Initial peak values Reference: -5.115dB Comparison: -5.114dB
Initial RMS values Reference: -24.002dB Comparison: -24.002dB
Null Depth=45.513dB
X-Correlation offset: 1 samples
Drift computation quality, #1: Excellent (0µs)
Trimmed 0 samples ( 0.00ms) front, 0 samples ( 0.00ms end)
Final peak values Reference: -5.115dB Comparison: -5.116dB
Final RMS values Reference: -24.002dB Comparison: -24.002dB
Gain= 0dB (1x) DC=0 Phase offset=0.006378ms (0.612 samples)
Difference (rms) = -67.88dB [-118.93dBA]
Correlated Null Depth=73.94dB [117.5dBA]
Clock drift: 0 ppm
Files are NOT a bit-perfect match (match=8.28%) at 16 bits
Files are NOT a bit-perfect match (match=0.05%) at 24 bits
Files match @ 49.9967% when reduced to 12.36 bits
---- Phase difference (full bandwidth): 0.0672281438513599°
0-10kHz: 0.00°
0-20kHz: 0.00°
0-24kHz: 0.03°
Timing error (rms jitter): 65.7ns
RMS of the difference of spectra: -149.641964871824dB
DF Metric (step=400ms, overlap=0%):
Median=-50.9dB
Max=-25.9dB Min=-57.7dB
1% > -57.52dB
10% > -54.51dB
25% > -53.44dB
50% > -50.88dB
75% > -47.02dB
90% > -43.26dB
99% > -21.13dB
Linearity 24.5bits @ 0.5dB error
PK Metric (step=400ms, overlap=50%):
RMS=-116.6dBr
Median=-130.0
Max=-89.0
99%: -111.84
75%: -128.55
50%: -130.04
25%: -131.55
1%: -134.86
gn=0.999999396412136, dc=3.00935242754951E-09, dr=0, of=0.6122974419
DONE!
Signature: ab5dba637a1bce48d8a161f522e87103
And finally my ABX test report
Code:
foo_abx 2.0.2 report
foobar2000 v1.4.8
2022-07-10 22:17:35
File A: BreakOn_1sh.wav
SHA1: 73fd67f8fb135adf5e0ec92bc9f2178bbe269709
File B: BreakOn_3sh.wav
SHA1: 80aebddcdc26e9851a9441ddc89aae59a2d099eb
Output:
ASIO : Topping USB Audio Device
Crossfading: NO
22:17:35 : Test started.
22:19:16 : 01/01
22:19:32 : 02/02
22:19:49 : 03/03
22:20:23 : 04/04
22:20:41 : 05/05
22:20:58 : 06/06
22:21:14 : 07/07
22:21:32 : 07/08
22:21:54 : 07/09
22:22:15 : 08/10
22:22:15 : Test finished.
----------
Total: 8/10
Probability that you were guessing: 5.5%
-- signature --
1fecd71c51663eee539fc9f3fb52be641d5de76f
Code:
foo_abx 2.0.2 report
foobar2000 v1.4.8
2022-07-11 10:03:01
File A: BreakOn_1sh.wav
SHA1: 73fd67f8fb135adf5e0ec92bc9f2178bbe269709
File B: BreakOn_3sh.wav
SHA1: 80aebddcdc26e9851a9441ddc89aae59a2d099eb
Output:
ASIO : Topping USB Audio Device
Crossfading: NO
10:03:01 : Test started.
10:05:08 : 01/01
10:05:28 : 02/02
10:05:43 : 02/03
10:06:09 : 03/04
10:06:23 : 04/05
10:06:39 : 04/06
10:06:53 : 05/07
10:07:13 : 06/08
10:07:27 : 07/09
10:08:06 : 08/10
10:08:06 : Test finished.
----------
Total: 8/10
Probability that you were guessing: 5.5%
-- signature --
aadf51dde71992c4a987ec42a7e1476dfe2ddba2
16/20 total result
Have fun!
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