esldude Posted March 31, 2019 Share Posted March 31, 2019 14 minutes ago, pkane2001 said: The 0 value at the center line is not in dB, as that can't be expressed in decibels (a log of 0 doesn't compute). The scale is in dBFS, so it’s 0dB at 1.0 and -1.0 and goes negative below that. Shows I am still tired from working too much in the recent days. I should have understood that. Skipping some versions I didn't notice the db scale instead of the fraction of 1 used in previous versions. So that was throwing me off. Sorry for the false alarm. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted March 31, 2019 Share Posted March 31, 2019 Hopefully this isn't me just being tired and missing something obvious. When zooming in on a waveform for the top half above zero level I get this. Notice the db level displayed with decimal places. This works into even more decimal places than this example. But a similar level of zooming on the bottom half of the waveform results in this where the decimal places aren't shown. You never get any db decimal places zooming on the bottom half of the waveform displayed. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 2, 2019 Share Posted April 2, 2019 1 hour ago, STC said: Thanks for the reply. I am trying to measure actual drift of two identical signal but one is delayed by 60 microseconds. I am trying to see if the output is also at 60microsec. Not sure if DW could do that. Thanks again. It probably could handle that just fine. You might give some more details of what the signal is. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 2, 2019 Share Posted April 2, 2019 3 hours ago, Jud said: Does it make the thing overly complex if you provide the option? I can think of reasons for both. I second this. It would be nice to have both at various times, but don't want to complicate the software by doing so. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 2, 2019 Share Posted April 2, 2019 The software is working great for me right now. I decided to "attack" it from a different direction. What are the most exact files I can give it to compare and how good can the null be? I set up a DAC and ADC separate, and used 60 seconds of music put together in a file with 4 copies of this snippet. Played and recorded one right after the other with couple seconds silence between. If the gear were perfect repeatable even if not perfectly distortion free two such files should get me nulls limited only by the noise floor. I then did the same thing only in a loopback with my recording ADC/DAC. Same clock so any clocking variations don't really matter. I would expect it to get very close to being a very deep null limited by noise. I chopped the files up and labeled them A thru D afterwards to compare. Well I can happily report the results with separate DAC and ADC are just as good as loopbacks. So that is impressive on timing alignment. They do vary more than I expected. Correlated nulls run 85 db to 105 db (one pair did manage 121 db). Listening to the difference file portions are just noise. But there are places here and there where you hear the music embedded into it or sometimes rather clearly (with 80 db extra gain). My first thought was timing drift or the timing correction drifting. But I don't think that is the cause. I think what I'm seeing is gain drift over time. It is tedious (but amazing we have this capability) to zoom into peaks and see the matched waveform. I find a level difference of .0001 to .0003 db on such peaks. The Reference is sometimes high and the compare file is sometimes high. It seems to drift around over several seconds. The timing of such peaks looks to usually be dead on as closely as I can look. I ran into this a decade ago comparing captures of interconnects. I didn't have this software (and boy would it have been nice to have), but I found the same issue was limiting the ultimate nulls. So Paul, am I misinterpreting what I'm seeing? Is there some reasonably doable way to check for gain drift as well as timing drift? And yes I know .000x db levels are very tiny. But they seem to be what is limiting better nulls into complete noise. And when I am lucky I've gotten a couple 60 second clips that are mostly just noise leftover for nearly half the 60 seconds. This is impressive performance. pkane2001 1 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 3, 2019 Share Posted April 3, 2019 1 hour ago, pkane2001 said: @fas42, next test. Converted the original file to 352.8k in Audacity, saved this as 16bit PCM. Slowed it down by 1 sample (still at 352.8k). Saved that file as 16 bit PCM. Used DeltaWave to compare (again, low pass filter at 20KHz): Very nice nulls, 75% bit perfect samples. Drift is shown as 0.09ppm. Let's see if that's right: 1/11019024 * 1e6 = 0.0908 or 0.09ppm. Exactly as reported. Again, working as expected. The only thing I can think of is that you are using the resampler in DeltaWave to match sample rates between 44.1k and 352.8k -- that's not recommended. The resampler is to be used only in the case of an emergency, I don't have any specs or measure;ments of its quality or even the algorithm used, it was just something provided by the audio library I'm using. At some point I may have to work on creating a resampler that's of a higher quality, but resampling was never part of the plan for DeltaWave, it was just an experiment. EDIT: Just ran the comparison between 44.1k/16 original and 352.8k/16 bit slowed down by 1 sample version. While the RMS null was lower, percent match remained very high at 80%, and drift rate is still exactly right at 0.09ppm. So yes, the resampler introduces some larger distortions, and while most samples match perfectly, the ones that don't, differ by more than without resampling. I'm not seeing the quality box or the clock drift tab. Are those upcoming improvements not yet out? Mine says 1.0.22 like yours. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 3, 2019 Share Posted April 3, 2019 I took a file, copied it and then applied some .001 db increase and decreases in volume. In a 60 second file, I had 15 seconds .001 db low and that many high scattered thru it. What I'm seeing is a gain variation about a third of this amount. But the results look very similar. Difference around -85 db and null depths of 100-105 db. Listening to the difference wave areas I didn't change are nearly gone, but not gone as they should be, and other areas have more prominent differences remaining. Much like my real results. So I do think I'm seeing these very small variance in playback levels over several seconds time. I don't know how you could fix that. Seems like it would be an issue like linear drift vs non-linear drift. Of course such an effect at that level has no bearing on any audible concerns, it just lowers the null depth you can manage with DW. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 4, 2019 Share Posted April 4, 2019 15 hours ago, pkane2001 said: Hi Dennis, While I can certainly add some correction, as well as measurement, of non-linear gain differences (had it before), I think correcting for them is potentially eliminating some non-trivial differences between the two tracks. I guess if you know that the ADC is causing this, you might want to eliminate it. To correct for ADC imperfections, I tested using a calibration file, either loop-back, an impulse response, or an REW-style sweep. The results were not great, although FR was corrected, nulls usually got worse. I suspect the additional noise and uncertainty in the measurement process just adds more noise into the final DW null calculation. For this reason, I'm much more inclined to just show non-linear gain differences on a chart rather than to try to correct them. Yes, I was asking as I didn't know, but rather thought it would end up like non-linear drift where it corrupted results. So if it is reasonably easy showing non-linear gain or non-linear level over time on a chart like you are now doing for drift would be just fine. This non-linear gain only becomes of enough difference to matter when null depths are 90 db or better. You can get to a point where it isn't distortion or noise or FR that is preventing a null of just noise, and most of the difference is this level variance over time. A chart would let you know that is the remaining issue. It also appears this level variance can very slightly fool DW into making tiny changes in timing drift that aren't from drift. I'll add a chart to this is a minute. Here is a loopback of Bela Fleck 60 seconds taken 2 minutes apart. Notice the very low scale of drift correction. After the 20 second or so mark with 85 db playback gain you hear mostly just noise with a few notes buried in the noise where you see the little peaks in this difference waveform. Oh also it appears whenever 0 ppm drift or negative drift is reported the Fit Quality is blank. pkane2001 1 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 4, 2019 Share Posted April 4, 2019 This one puzzles me. This was with separate DAC and ADC, you see the results are excellent. You hear very little other than noise over the majority of the difference here. Yet it shows poor Fit Quality and it looks like drift was zero, but corrected drift was a steady 4.3 samples. This was with non-linear EQ matching on . DeltaWave v1.0.23, 2019-04-03T22:02:39.1435823-05:00 Reference: Fleck B M ZT44.wav[L] 2997082 samples 44100Hz 24bits, stereo, MD5=00 Comparison: Fleck C M ZT44.wav[L] 2947706 samples 44100Hz 24bits, stereo, MD5=00 Settings: Gain:True, Remove DC:True Non-linear Gain:True EQ FFT Size:32768, EQ Frequency Cut: 0Hz - 0Hz, EQ Threshold: -160dB Correct Drift:True, Precision:8 Upsample:False, Window:Hann Spectrum Window:BlackmanHarris, Spectrum Size:16384 Spectrogram Window:BlackmanHarris, Spectrogram Size:2048, Spectrogram Steps:2048 Dither:False Trim Silence:False Discarding Reference: Start=0s, End=0s Discarding Comparison: Start=0s, End=0s Initial peak values Reference: -1.484dB Comparison: -1.493dB Initial RMS values Reference: -19.291dB Comparison: -19.219dB Null Depth=12.723dB X-Correlation offset: 16973 samples Drift computation quality, #1: Good (9.83μs) Final peak values Reference: -1.483dB Comparison: -1.483dB Final RMS values Reference: -19.266dB Comparison: -19.219dB Gain= -0.0003dB (1x) DC=0 Phase offset=384.885104ms (16973.433 samples) Difference (rms) = -93.02dB [-97.6dBA] Correlated Null Depth=100.53dB [96.13dBA] Clock drift: 0 ppm Files are NOT a bit-perfect match (match=36.85%) at 16 bits Files are NOT a bit-perfect match (match=0.16%) at 24 bits Files match @ 50.0214% when reduced to 15.43 bits Phase difference (full bandwidth): 103.722560858338° 0-10,000Hz: 103.845306648601° 0-20,000Hz: 103.790955948447° 0-24,000Hz: 103.722560858338° 0-44,100Hz: 103.722560858338° 0-48,000Hz: 103.722560858338° RMS of the difference of spectra: -118.168645054746dB gn=1.00003064249035, dc=-6.89464619492245E-07, dr=0, of=16973.4331 DONE! Signature: 08d8fb6e1c9f19f37c93f7008e1c67a9 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 4, 2019 Share Posted April 4, 2019 This one is a bit of a puzzler on drift as well. This is two different sample rates. DeltaWave v1.0.23, 2019-04-03T22:22:49.3019717-05:00 Reference: Fleck C M ZT88.wav[L] 5998206 samples 88200Hz 24bits, stereo, MD5=00 Comparison: Fleck B M ZT44.wav[L] 2997082 samples 44100Hz 24bits, stereo, MD5=00 Settings: Gain:True, Remove DC:True Non-linear Gain:True EQ FFT Size:32768, EQ Frequency Cut: 0Hz - 0Hz, EQ Threshold: -160dB Correct Drift:True, Precision:8 Upsample:False, Window:Hann Spectrum Window:BlackmanHarris, Spectrum Size:16384 Spectrogram Window:BlackmanHarris, Spectrogram Size:2048, Spectrogram Steps:2048 Dither:False Trim Silence:False Resampled Reference to 44100Hz Discarding Reference: Start=0s, End=0s Discarding Comparison: Start=0s, End=0s Initial peak values Reference: -1.476dB Comparison: -1.484dB Initial RMS values Reference: -19.289dB Comparison: -19.291dB Null Depth=14.722dB X-Correlation offset: 6484 samples Drift computation quality, #1: Excellent (1.02μs) Final peak values Reference: -1.475dB Comparison: -1.476dB Final RMS values Reference: -19.28dB Comparison: -19.286dB Gain= -0.0002dB (1x) DC=0 Phase offset=147.030234ms (6484.033 samples) Difference (rms) = -72.43dB [-72.64dBA] Correlated Null Depth=83.15dB [76.72dBA] Clock drift: 0 ppm Files are NOT a bit-perfect match (match=9.06%) at 16 bits Files are NOT a bit-perfect match (match=0.04%) at 24 bits Files match @ 49.9928% when reduced to 12.65 bits Phase difference (full bandwidth): 103.944085755163° 0-10,000Hz: 104.05076201756° 0-20,000Hz: 103.955692484385° 0-24,000Hz: 103.944085755163° 0-44,100Hz: 103.944085755163° 0-48,000Hz: 103.944085755163° RMS of the difference of spectra: -98.308537228845dB gn=1.00002839613872, dc=-8.87187440967148E-07, dr=0, of=6484.0333 DONE! Signature: c83426d6d9205613d67034db97ce8d96 See what happens when you give us new info to get puzzled over. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 5, 2019 Share Posted April 5, 2019 https://www.dropbox.com/s/i1da2819glgtqt9/DW tests.zip?dl=0 Here are the files I showed in posts up the thread yesterday. Fleck B loop and Fleck C loop were the first pairing. Fleck B M ZT44 and Fleck C M ZT44 were the second pairing. Fleck B M ZT44 and Fleck C M ZT88 were the third pairing. If you look at my prior posts with the results quoted you can duplicate my settings. The first pair were consecutive loopbacks on my Zen Tour interface at 44 khz. The second pair were the March Audio DAC1 feeding my Zen Tour ADC at 44 khz. The third pair were the March feeding my Zen Tour and the same thing only recorded at 88 khz. Here are links to those prior posts. https://audiophilestyle.com/forums/topic/55878-deltawave-null-testing-audio-comparator-beta/?do=findComment&comment=945465 https://audiophilestyle.com/forums/topic/55878-deltawave-null-testing-audio-comparator-beta/?do=findComment&comment=945472 https://audiophilestyle.com/forums/topic/55878-deltawave-null-testing-audio-comparator-beta/?do=findComment&comment=945476 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 5, 2019 Share Posted April 5, 2019 3 hours ago, pkane2001 said: Dennis, I think you have set your precision too low in settings. You have it at 8. I usually run mine at 30. I think that's what's making the difference. I'll make 30 the default and hide the selection in the next update I wanted to do this for a while, as this selector was more for me to test how sensitive the algorithm was to the number of loop iterations and the remaining error. I thought I remembered you saying 8 was less CPU intensive and usually more resulted in little improvement. No big deal I'll run it at 30. The first one had a different looking drift which still puzzles me. Results were nearly identical as was the delta waveform. DeltaWave v1.0.23, 2019-04-05T10:23:34.2946471-05:00 Reference: Fleck B loop.wav[L] 2973882 samples 44100Hz 24bits, stereo, MD5=4b3490e8f2cbc0ce887f3709ee29bd52 Comparison: Fleck C loop.wav[L] 2998705 samples 44100Hz 24bits, stereo, MD5=208a967c4c1672904fb42e63f2199021 Settings: Gain:True, Remove DC:True Non-linear Gain:False EQ FFT Size:32768, EQ Frequency Cut: 0Hz - 0Hz, EQ Threshold: -160dB Correct Drift:True, Precision:30 Upsample:False, Window:Hann Spectrum Window:BlackmanHarris, Spectrum Size:16384 Spectrogram Window:BlackmanHarris, Spectrogram Size:2048, Spectrogram Steps:2048 Dither:False Trim Silence:False Discarding Reference: Start=0s, End=0s Discarding Comparison: Start=0s, End=0s Initial peak values Reference: -1.55dB Comparison: -1.554dB Initial RMS values Reference: -19.33dB Comparison: -19.371dB Null Depth=12.187dB X-Correlation offset: -6229 samples Drift computation quality, #1: Excellent (0μs) Final peak values Reference: -1.55dB Comparison: -1.549dB Final RMS values Reference: -19.33dB Comparison: -19.357dB Gain= -0.0048dB (0.9995x) DC=0 Phase offset=-141.247166ms (-6229 samples) Difference (rms) = -100.14dB [-103.63dBA] Correlated Null Depth=106.07dB [100.28dBA] Clock drift: 0 ppm Files are NOT a bit-perfect match (match=59.35%) at 16 bits Files are NOT a bit-perfect match (match=0.33%) at 24 bits Files match @ 50.0328% when reduced to 16.43 bits Phase difference (full bandwidth): 103.891656335844° 0-10,000Hz: 103.87162265712° 0-20,000Hz: 103.879383030978° 0-24,000Hz: 103.891656335844° 0-44,100Hz: 103.891656335844° 0-48,000Hz: 103.891656335844° RMS of the difference of spectra: -126.717089946118dB gn=1.00054742974416, dc=2.17074271537381E-09, dr=0, of=-6229 DONE! Signature: fca2c45764ab56020e4589f21e8e1c53 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 5, 2019 Share Posted April 5, 2019 The second one drift looks different, but results are virtually the same once again. DeltaWave v1.0.23, 2019-04-05T10:34:44.5663954-05:00 Reference: Fleck B M ZT44.wav[L] 2997082 samples 44100Hz 24bits, stereo, MD5=5d44e8378ed9a67f66b588dbc09df65c Comparison: Fleck C M ZT44.wav[L] 2947706 samples 44100Hz 24bits, stereo, MD5=7e82d9fe4b946983abcf3438e31bb5e5 Settings: Gain:True, Remove DC:True Non-linear Gain:True EQ FFT Size:32768, EQ Frequency Cut: 0Hz - 0Hz, EQ Threshold: -160dB Correct Drift:True, Precision:30 Upsample:False, Window:Hann Spectrum Window:BlackmanHarris, Spectrum Size:16384 Spectrogram Window:BlackmanHarris, Spectrogram Size:2048, Spectrogram Steps:2048 Dither:False Trim Silence:False Discarding Reference: Start=0s, End=0s Discarding Comparison: Start=0s, End=0s Initial peak values Reference: -1.484dB Comparison: -1.493dB Initial RMS values Reference: -19.291dB Comparison: -19.219dB Null Depth=12.723dB X-Correlation offset: 16973 samples Drift computation quality, #1: Excellent (0.01μs) Final peak values Reference: -1.483dB Comparison: -1.483dB Final RMS values Reference: -19.266dB Comparison: -19.219dB Gain= -0.0003dB (1x) DC=0 Phase offset=384.885104ms (16973.433 samples) Difference (rms) = -93.02dB [-97.6dBA] Correlated Null Depth=100.51dB [96.13dBA] Clock drift: 0 ppm Files are NOT a bit-perfect match (match=36.85%) at 16 bits Files are NOT a bit-perfect match (match=0.16%) at 24 bits Files match @ 50.0214% when reduced to 15.43 bits Phase difference (full bandwidth): 103.722560858339° 0-10,000Hz: 103.845306648597° 0-20,000Hz: 103.790955948448° 0-24,000Hz: 103.722560858339° 0-44,100Hz: 103.722560858339° 0-48,000Hz: 103.722560858339° RMS of the difference of spectra: -118.168645054741dB gn=1.00003064249035, dc=-6.89464619491202E-07, dr=0, of=16973.4331 DONE! Signature: c4f5c295aa0333fddc2f6b3394f4ec15 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 5, 2019 Share Posted April 5, 2019 Results for the third example were very slightly less good. Again drift chart looks different, while delta wave is pretty much the same. I'm wondering why Deltawave seems to over-correct or slightly mis-correct for drift at these low drift differences and deep nulls. Seems if this were a little better it is very, very close to showing just noise between these examples. I'm still thinking very slow and very small level changes over the track are causing this. I get that such things aren't reasonably correctable, and we might not want it corrected. If it is possible to show when that is happening it would be good. I suppose I'm still on shaky ground to propose that is what causes this behavior. DeltaWave v1.0.23, 2019-04-05T10:42:38.0272508-05:00 Reference: Fleck C M ZT88.wav[L] 5998206 samples 88200Hz 24bits, stereo, MD5=5a4783cd1548219e149e1becc7dda234 Comparison: Fleck B M ZT44.wav[L] 2997082 samples 44100Hz 24bits, stereo, MD5=5d44e8378ed9a67f66b588dbc09df65c Settings: Gain:True, Remove DC:True Non-linear Gain:True EQ FFT Size:32768, EQ Frequency Cut: 0Hz - 0Hz, EQ Threshold: -160dB Correct Drift:True, Precision:30 Upsample:False, Window:Hann Spectrum Window:BlackmanHarris, Spectrum Size:16384 Spectrogram Window:BlackmanHarris, Spectrogram Size:2048, Spectrogram Steps:2048 Dither:False Trim Silence:False Resampled Reference to 44100Hz Discarding Reference: Start=0s, End=0s Discarding Comparison: Start=0s, End=0s Initial peak values Reference: -1.476dB Comparison: -1.484dB Initial RMS values Reference: -19.289dB Comparison: -19.291dB Null Depth=14.722dB X-Correlation offset: 6484 samples Drift computation quality, #1: Excellent (0.05μs) Final peak values Reference: -1.475dB Comparison: -1.476dB Final RMS values Reference: -19.28dB Comparison: -19.286dB Gain= -0.0002dB (1x) DC=0 Phase offset=147.030229ms (6484.033 samples) Difference (rms) = -72.34dB [-72.55dBA] Correlated Null Depth=80.07dB [76.95dBA] Clock drift: 0 ppm Files are NOT a bit-perfect match (match=8.78%) at 16 bits Files are NOT a bit-perfect match (match=0.03%) at 24 bits Files match @ 50.0095% when reduced to 12.61 bits Phase difference (full bandwidth): 103.944093471781° 0-10,000Hz: 104.052752272572° 0-20,000Hz: 103.9557925736° 0-24,000Hz: 103.944093471781° 0-44,100Hz: 103.944093471781° 0-48,000Hz: 103.944093471781° RMS of the difference of spectra: -98.2118923336474dB gn=1.00002834172103, dc=0, dr=0, of=6484.0331 DONE! Signature: 3719325743fed3fb2be16d1e2e7539a0 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 5, 2019 Share Posted April 5, 2019 4 minutes ago, pkane2001 said: Considering the scale of the error, I wouldn't read too much into this. The error is on the order of 1/100000 of a sample or about 0.2 nano-seconds. This is well below the accuracy of the phase offset measurement algorithm. Some of the changes I'm working on might help improve this plot a little, but the overall null values are not going to change by much. Yes, I had noticed that. So would these files with very low nulls improve if you used alignment to 1/100,000th of a sample or is that not reasonably doable? And yes I know when we are talking of such very small differences the voltages and noise levels are such we have gotten way down into the mud of the analog world. That your software gets this far is very impressive. When the nulls are 90 db or more and you hear about as much noise as anything with 80 db extra gain we are at the point I can't conceive of any of the difference being audible. Its more of a measurement oriented intellectual curiosity. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 5, 2019 Share Posted April 5, 2019 1 hour ago, pkane2001 said: If it's shown as 0ppm then the correction was not applied. The drift error plot might be wrong in reporting the last measured error, and not the one after all the corrections are applied. I'm fixing that in the next update. Ah! That is a bit different then. Those small differences plotted weren't applied. So it makes more sense. pkane2001 1 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 6, 2019 Share Posted April 6, 2019 2 hours ago, fas42 said: Not doing much until the next version appears, but came across this artifact - DW appears to be adding ringing to the start of the matched waveforms, DeltaWave v1.0.23, 2019-04-06T12:47:25.9930668+11:00 Reference: BM,orig.wav[L] 5898049 samples 176400Hz 32bits, stereo, MD5=00 Comparison: BM,1st.wav[L] 6005308 samples 176400Hz 32bits, stereo, MD5=00 Settings: Gain:True, Remove DC:True Non-linear Gain:False EQ FFT Size:262144, EQ Frequency Cut: 0Hz - 0Hz, EQ Threshold: -160dB Correct Drift:True, Precision:30 Upsample:True, Window:Hann Spectrum Window:Blackman, Spectrum Size:524288 Spectrogram Window:Lanczos, Spectrogram Size:32768, Spectrogram Steps:1024 Dither:False Trim Silence:False Discarding Reference: Start=2.3s, End=0s Discarding Comparison: Start=3.5s, End=0s Initial peak values Reference: -1.49dB Comparison: -1.414dB Initial RMS values Reference: -17.644dB Comparison: -17.68dB Null Depth=12.52dB X-Correlation offset: 6211 samples Drift computation quality, #1: Excellent (0.23μs) Final peak values Reference: -1.783dB Comparison: -1.783dB Final RMS values Reference: -22.691dB Comparison: -22.774dB Gain= 0.0536dB (1.0062x) DC=0 Phase offset=35.207286ms (6210.565 samples) Difference (rms) = -63.76dB [-65.56dBA] Correlated Null Depth=65.61dB [61.32dBA] Clock drift: 0.63 ppm Files are NOT a bit-perfect match (match=6.33%) at 16 bits Files are NOT a bit-perfect match (match=0%) at 32 bits Files match @ 50.0017% when reduced to 11.1 bits RMS of the difference of spectra: -170.016220084506dB gn=0.993850366235055, dc=0, dr=6.349E-07, of=6210.5653 DONE! Signature: dae5f91427d7bcc8ca454fdd09ab2496 Writing difference file to: D:\DELLTOP\My\Docs\Audio\Sound\AS~CA\BM,orig~1st(176);100,HP.wav I'm not seeing this in the original sample rates Frank. Maybe some artifact of upsampling? pkane2001 1 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 7, 2019 Share Posted April 7, 2019 Glad to have another update. I've been recording some files on multiple devices this afternoon. Typically a one generation copy gets me something like a 55-60 db null depth. Still have to do some evaluation of the latest recordings. So what is keeping it from being more? Doesn't seem to be FR. I wouldn't think distortion is the reason. So is it not good enough drift correction? Not good enough level matching? Phase differences? Is there a good way to figure this out? Test signals could do that, but DW doesn't line up well with most test signals. Best test signal I've come up with, but not written about is a low to high sawtooth sweep at the same time as I'm doing a high to low sawtooth sweep. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 8, 2019 Share Posted April 8, 2019 5 minutes ago, pkane2001 said: 55-60dB RMS null is actually good for an analog recording compared to digital source. If you check the DAC/ADC loopback archives on DIYaudio, you'll see that most fall below that level. The better DAC/ADC loops I've seen there came to about a 70-75dB null (and I've been checking their numbers with DW -- DW usually reports numbers that are at least as good, often better than what's reported there). The way to figure out what's happening is to check the various plots and results and to go from there: Check that the start/end of the two tracks are not causing a large error -- often ADCs take time to synchronize, so trim a second or two at least from the start of each track Start by looking at spectral comparison plots. If you are comparing the original with the first generation, there will be some sort of filter that will cause the null to be worse. Apply a low-pass filter in DW just below where the two spectral plots diverge and see if the null improves Check if A-weighted null values are better -- if yes, there may be differences in very low frequencies or high on the audio spectrum If RMS null is significantly lower than correlated null, this indicates problems with level matching -- phase alignment is good, but level may be non-linearly related between the two tracks. I'll add a chart to show average gain differences over time which hopefully will illustrate this in more detail Check the delta of spectra plot. Does it look linear? Are the areas where spectra diverge significantly? This could point to frequency-related issues. If yes, try engaging non-linear EQ. Check the clock drift plot. Zoom-in to the level where the remaining drift is no longer a single line. Does it look mostly linear, or oscillating? What's the magnitude? There may be some clock modulation by noise or signal that causes clock variations between DAC and ADC. The remaining drift will tell you that Zoom-in to the same level at the beginning, middle and end of the aligned track waveforms. Do they look equally well-aligned in time? Level? Check phase difference plot. Is it chaotic and with no patterns? Does the error increase towards high frequencies? Or does it look like the plot is bent, like on a curve? This could be indications of non-linear clock differences Any kind of sweep that changes in frequency with time should be a good one to use with DW. It is a repeating wave at the same frequency over a period of time that will give it trouble. This is only because the drift measurement calculation relies on only one point at each part of the waveform to align best with the other. If there are multiple such points that cannot be distinguished from each other, the drift calculation will fail. Yes all good suggestions. Also why I'm making some recordings with a few different devices to see what the relative strength and differences are. About the phase plot, what is a reasonable lower limit to place on it. I can make it so high phase is always a straight line or so low it is chaotic. How do you know where a good point to choose for that lies? And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 8, 2019 Share Posted April 8, 2019 In changing the level of phase in settings, 60, 78 and 96 aren't retained. It looks blank after resetting. It does appear the setting is held and used in the software for the next match, but it doesn't show up. Lower values do show in the box if you reset them. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
Popular Post esldude Posted April 8, 2019 Popular Post Share Posted April 8, 2019 Alright some worthwhile finding using multiple devices already. Here is a loopback of my Focusrite 18i20 vs itself a couple minutes later. As you would expect when you listen to it with 85 db gain, there is nothing except noise. No music at all. There is a low howling tone, which is 120 hz and 180 hz hum coming thru. Hard to hear even it is so low. The Focusrite Forte gets a similar result without the hum related stuff. Clock drift looks very, very good too. The delta spectrum is good and if I switch it to log scale you clearly see the low end peaks are hum related. Though I don't show that here. But loopbacks with my Zen Tour are good, but not this good compared to itself. It appears to have a little timing drift. I don't know if they use separate clocks for ADC or DAC or if the way they are connected causes some issue. The delta wave listened to is still pretty good, but music is heard drifting in and out in level sometimes almost gone other times not. So is the Antelope device which makes their name with their fantastic clocks not well clocked? There is some evidence what really happens is level shifting over time. The difference RMS being lower than the correlated nulls. I'll need to experiment using the clock from the Antelope as an external clock on one of my other devices and see if it causes the same issue. That should tell me if it is the clock or level drift. Sure would be something if the company that hangs its hat on its great clocking has a drifty so so clock. STC, fas42 and pkane2001 2 1 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
Popular Post esldude Posted April 9, 2019 Popular Post Share Posted April 9, 2019 17 hours ago, pkane2001 said: Thanks, Frank! Am I wrong or does it appear that the fraction in the gain factor makes the largest difference? I think I may know what's causing that: DW is measuring the first quarter or so of the track to determine proper gain match coefficients. Since the delta wave for this particular track shows a growing amplitude error towards the end, DW is not using that part in the computation. This was an optimization to speed up processing, but perhaps I need to rethink that! Probably not an issue with most tracks that have a simple constant amplitude error I too think the gain matching needs improvement, and should use the whole file. I've also noticed some tracks have error concentrated either at both ends or toward the middle depending upon the track. And that stays consistent with different gear in use. I've one that seems to usually produce a great null at the beginning and then get worse gradually toward the end across multiple pieces of gear. I need to sit down and go over this again to make sure that is consistent. It does seem related to gear having a drift in gain levels. But you only see it once the nulls are pretty good to begin with. @fas42 you might want to get an earlier version of Audacity. I forget when it changed. It was not too long after 2.0 status of Audacity. 2.0.3 maybe? These earlier versions allowed speed changes down to .3 parts per billion and seemed smoother. These versions also allowed gain changes to something like 11 decimal places. I need to fire up an old, old laptop I keep such a version on and tell you which one to look for. Good news is that DW seems to consistently show differences in clocking. I spent some time yesterday using external clocking. Some other aspects are puzzling at first glance. One clock seems to bump the nulls of my Zen tour by over 10 db (some of those are differences of 100 db or lower and null depths of 110 db), and my 18i20 by 6 or so db. This is comparing consecutive runs to themselves. But it has an occasional glitch somehow. So you have to run it a few times and get lucky. Though you see the glitch when it happens in the difference file and it is very low except when a glitch happens. Using this clock with the Zen Tour consecutive runs compared leave faint noise, but you can still hear very faintly the music. You must use about 95 db of gain to hear it however. My other interfaces you hear only noise, but the noise is higher in level so the same residual of music would be obscured. While the correlated null depth as well as difference RMS is useful info (and the dbA versions too) I find the best indicator between devices to be difference RMS minus final RMS for the track. I know the read out has gotten full, but maybe this is worth putting on the results line at the bottom or at least make it an option. fas42 and pkane2001 1 1 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 10, 2019 Share Posted April 10, 2019 @fas42 Audacity 2.0.5 has the enhanced speed and gain changes. You can change the speed percent by as little as .00000003 while it will let you enter more digits if you get past this number nothing actually changes. So 7 zeroes and a 3 or higher will change speed. Gain changes can be as little as .000001 db. Again it will let you input more zeroes, but nothing actually happens. The current version only allows 2 zeroes past the decimal instead of 5. You can download 2.0.5 here. https://code.google.com/archive/p/audacity/downloads I have it running on an old laptop with Win 8. Don't know how it runs with Win 10. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 10, 2019 Share Posted April 10, 2019 Here is something interesting. Not sure what to make of it. The first two drift graphs are from a loopback on my Zen Tour vs the original music file. Done several days apart. These two are a Zen Tour loopback but with external clocking by a Focusrite 18i20 and then a Musical Fidelity Vlink. This one is with a March DAC feeding the Zen Tour so no loopback. Looks like the content of the file itself is creating a common pattern in the corrected drift plot. Below are two plots using a different snippet of music. First a ZT loopback and then March feeding the ZT. I've also checked with external clocking seeing the same pattern, but it is redundant to post them all. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted April 10, 2019 Share Posted April 10, 2019 Here is more I don't know what to make of it. Using loopback for the same music file vs the original I see the same drift pattern shape. Only notice the scale of that pattern is 5 times greater. And using loopbacks from the 18i20 once again the same pattern only at an even larger scale. Not sure what if anything this means. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
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