Evaluating AD\/DA loops by means of Audio Diffmaker – Gearslutz Pro Audio Community<\/a><\/p>\n <\/p>\n
DiffMaker was used to test for\u00a0audible effects of<\/span><\/p>\n\n- Changing interconnect cables (compensation for cable capacitance may be required)<\/li>\n
- Different types of basic components (resistors, capacitors, inductors)<\/li>\n
- Special power cords<\/li>\n
- Changing loudspeaker cables (cable inductance may need to be matched or compensated)<\/li>\n
- Treatments to audio CDs (pens, demagnetizers, lathes, dampers, coatings…)<\/li>\n
- Vibration control devices<\/li>\n
- EMI control devices<\/li>\n
- Paints and lacquers used on cables, etc.<\/li>\n
- Premium audio connectors<\/li>\n
- Devices said to modify electrons or their travel, such as certain treated “clocks”<\/li>\n
- Different kinds of operational amplifiers, transistors, or vacuum tubes<\/li>\n
- Different kinds of CD players<\/li>\n
- Changing between power amplifiers<\/li>\n
- General audio “tweaks” said to affect audio signals (rather than to affect the listener directly)<\/li>\n
- Anything else where the ability to change an audio signal is questioned<\/li>\n<\/ul>\n
There’s interesting metric called ‘Correlated Null Depth’<\/strong> that can detect most subtle changes\u00a0as measurable data. Archimago refers to this metric as below if you’re\u00a0following his measurement tests.<\/p>\n <\/p>\n
The higher this value, the more correlated the 2 samples are (ie. the “closer” they sound).<\/strong><\/p>\n <\/p>\n
Now I hope you understand better about DiffMaker and correlation depth. Let’s proceed to the methodology part.\u00a0After a few runs of Diffmaker’s tests for a few weeks,\u00a0this was the method I used in final version.<\/p>\n
1. Setup master file and audio playback\/recording through digital domain. In this case, I’ll use VB-Audio Virtual Cable, foobar2000, and Audacity on Windows 10.
\n2. Prepare aligned master files with silence added.\u00a0For basic demonstration, I’ll make 5\u00a0samples of aligned\/before\/after\u00a0wav files with Audacity at 24\/96 format (10ms latency).
\n3. Route bit-perfect recording from\u00a0Virtual Cable’s master audio stream with\u00a0Foobar2000’s WASAPI output to Audacity’s WASAPI input, export audio as before.wav
\n4. Use\u00a0free version of Fidelizer at Purist user level with updated foobar2000 configuration from Fidelizer’s User Guide,\u00a0record again, export audio as after.wav
\n5. Compare results using\u00a0Audio\u00a0DiffMaker\u00a0with master file as reference.<\/p>\n
Testing machine ran\u00a0on\u00a0AMD FX8350 with 8 cores 4.2GHz and 8MB cache for L2\/L3. I also used high quality motherboard with 16GB RAM and Platinum grade PSU. Here’s the result\u00a0from my experiment.<\/p>\n
<\/p>\n
Perfected\u00a0master<\/strong><\/p>\n\n\n
parameters: 0sec, 0.000dB (L), \u00a00.000dB (R)..Corr Depth: 300.0 dB (L), 300.0 dB (R)<\/div>\n<\/div>\n<\/blockquote>\n
This is ideal result of exact comparison with 300.0 dB of\u00a0correlation depth<\/p>\n
<\/p>\n
Aligned master<\/strong><\/p>\n\n\n
parameters: -3.5sec, 0.000dB (L), 0.000dB (R)..Corr Depth: 175.6 dB (L), 174.0 dB (R)
\nparameters: -4.5sec, 0.000dB (L), 0.000dB (R)..Corr Depth: 168.5 dB (L), 168.6 dB (R)
\nparameters: -5.5sec, 0.000dB (L), 0.000dB (R)..Corr Depth: 167.4 dB (L), 167.5 dB (R)
\nparameters: -6.5sec, 0.000dB (L), 0.000dB (R)..Corr Depth: 166.3 dB (L), 167.0 dB (R)
\nparameters: -7.5sec, 0.000dB (L), 0.000dB (R)..Corr Depth: 172.5 dB (L), 176.1 dB (R)<\/div>\n<\/div>\n<\/blockquote>\n
Average: 0.000dB (0.000-0.000)..Corr Depth: 170.35 dB (166.3-176.1)
\nMedian: 0.000dB..Corr Depth: 168.55\u00a0dB<\/p>\n
Dropped to nearly 50% of perfect data but still above 150 dB.\u00a0With 9.8 dB swing range, it’s safe to assume about 5% threshold for evaluation.<\/p>\n
<\/p>\n
Before Fidelizer<\/strong><\/p>\n\n\n
parameters: -1.581sec, 0.001dB (L), 0.001dB (R)..Corr Depth: 90.6 dB (L), 91.5 dB (R)
\nparameters: -1.184sec, 0.001dB (L), 0.001dB (R)..Corr Depth: 87.2 dB (L), 87.3 dB (R)
\nparameters: -1.018sec, 0.001dB (L), 0.001dB (R)..Corr Depth: 88.1 dB (L), 88.1 dB (R)
\nparameters: -946.4msec, 0.001dB (L), 0.001dB (R)..Corr Depth: 88.3 dB (L), 86.3 dB (R)
\nparameters: -686.3msec, 0.001dB (L), 0.001dB (R)..Corr Depth: 90.2 dB (L), 87.6 dB (R)<\/div>\n<\/div>\n<\/blockquote>\n
Average: 0.001dB (0.001-0.001)..Corr Depth: 88.52 dB (86.3-91.5)
\nMedian: 0.001dB..Corr Depth: 88.1 dB<\/p>\n
Real world\u00a0result arrived with quite narrowed range. It’s only \u00a05.2 dB between min\/max of\u00a0correlation depth.\u00a0At least it’s more reliable than aligned result.<\/p>\n
<\/p>\n
After Fidelizer<\/strong><\/p>\n\n\n
parameters: -563.4msec, 0.001dB (L), 0.001dB (R)..Corr Depth: 104.0 dB (L), 95.9 dB (R)
\nparameters: -1.025sec, 0.001dB (L), 0.001dB (R)..Corr Depth: 93.5 dB (L), 94.0 dB (R)
\nparameters: -1.286sec, 0.001dB (L), 0.001dB (R)..Corr Depth: 87.2 dB (L), 87.3 dB (R)
\nparameters: -1.025sec, 0.001dB (L), 0.001dB (R)..Corr Depth: 88.1 dB (L), 88.2 dB (R)
\nparameters: -856.4msec, 0.001dB (L), 0.001dB (R)..Corr Depth: 90.4 dB (L), 87.6 dB (R)<\/div>\n<\/div>\n<\/blockquote>\n
Average: 0.001dB (0.001-0.001)..Corr Depth: 91.62 dB (87.2-104.0)
\nMedian: 0.001dB..Corr Depth: 89.3 dB<\/p>\n
It started great with over 100 dB but the rest seems to wear\u00a0down over time a bit\u00a0because\u00a0I also opened Chrome to chat in Facebook while during the experiment for daily usage tests.\u00a0Strict tests for high quality result\u00a0may lead to\u00a0faking data abuse from people who can’t do a proper job.<\/p>\n
With Fidelizer’s optimizations, we detected\u00a03.1 dB increment of average and 12.5 db increment of maximum correlation depth<\/strong>\u00a0with general improvements on other\u00a0metrics too. I shall conclude that there’s\u00a0measurable improvement with bit-perfect playback in digital audio.<\/p>\nYou can also try running performing this\u00a0test on your own and adjust DiffMaker configuration to show different kinds of data without rounding error or with\u00a0other standards. Have fun measuring\u00a0audio software optimizations with DiffMaker!<\/p>\n
Regards,
\nKeetakawee<\/p>\n","protected":false},"excerpt":{"rendered":"
It’s been a challenge to measure\u00a0digital audio’s qualities and most of the time\u00a0audiophiles don’t know any measurement outside RMAA’s analog metrics and got failed evaluations as you can see below: This was done through pure software environment using\u00a0VB-Audio Virtual Cable to make sure no hardware’s error is involved.\u00a0After lengthy research in pro audio’s communities, I found DiffMaker\u00a0being\u00a0used in…<\/p>\n
Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[54],"tags":[50,108,109,107,7,110],"class_list":["post-846","post","type-post","status-publish","format-standard","hentry","category-article","tag-bit-perfect","tag-correlation-depth","tag-diffmaker","tag-digital-audio","tag-fidelizer","tag-measurement"],"_links":{"self":[{"href":"https:\/\/fidelizer-audio.com\/wp-json\/wp\/v2\/posts\/846"}],"collection":[{"href":"https:\/\/fidelizer-audio.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fidelizer-audio.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fidelizer-audio.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fidelizer-audio.com\/wp-json\/wp\/v2\/comments?post=846"}],"version-history":[{"count":0,"href":"https:\/\/fidelizer-audio.com\/wp-json\/wp\/v2\/posts\/846\/revisions"}],"wp:attachment":[{"href":"https:\/\/fidelizer-audio.com\/wp-json\/wp\/v2\/media?parent=846"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fidelizer-audio.com\/wp-json\/wp\/v2\/categories?post=846"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fidelizer-audio.com\/wp-json\/wp\/v2\/tags?post=846"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
![\"Fidelizer](\"https:\/\/fidelizer-audio.com\/wp-content\/uploads\/2016\/07\/rmaa.jpg\")
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