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About esldude

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  1. Wow so 1 millionth of a sample? I look forward to this new version.
  2. Hard to believe there was no fire suppression system in the roof structure. Yet the stone vaulted ceilings were partly used for just this reason. To allow fires to burn the roof away and protect the important structure and interior. Those guys knew what they were doing it appears.
  3. The above is also a case where doing L+R is better than doing L or doing R alone. In the left channel I had the same sweeps as the right channel, but with the file reversed. So it was a 20hz to 20 khz sweep in that channel. As you can see even with no filtering this one is improved by 20 db over either channel alone compared. Fit is now excellent, and clock drift is closer to correct.
  4. Just so you won't feel the work on filtering at start or end was wasted effort. I have a signal showing filtering at the start can be beneficial. The signal was a 20khz to 20 hz sweep. Combined with various other short partial sweeps and silence so the waveform might give the software something to sink its teeth in. Reference was compared to the same file slowed by 10 ppm in Audacity. First up is with no filters. Results aren't so good with only a very good fit quality. Next is filtering LP at 20 khz at the end. Really no help at all. Next is LP set to 20 khz with filtering at the start. You see fit become excellent, difference improves more than 20 db as do null depths. The clock drift now is very close to the known amount of 10 ppm.
  5. Yes this null over time graphic would be very useful. Oh, my previous post was meant as a joke. The joke being to complain when currently the results are so good. You've made plenty of improvement in a short time. Deltawave is currently very impressive software.
  6. Okay, so I've recorded some loopbacks and done them a minute or two apart. Clocks are the same, gear the same etc etc. you'd expect nothing except noise if the two are properly aligned and nulled with each other. So I gave it a try in Paul's newest version of Deltawave. Okay here is the delta or difference between two such files. Did not leave me much to look at here. This is what it looks like in Audacity. Then there is this pathetic graph of the error distribution. It clusters around something like -130db. What is that going to tell you? Ha! So in this loopback mode with these gain settings the effective silent noise floor is maybe around -108 or -110 db A-wtd. I suppose a null result of -103.8 db A-wtd isn't too far off the mark. It isn't perfect though. There are hints of the music and the vocal now and again. Well if you apply 90 db of gain there is. Here is a link to the Delta wave of this comparison so you can listen for yourself. I would suggest 90 db of gain otherwise it will be kind of a null listening experience. https://www.dropbox.com/s/ims9mos2798xviq/Caram zt loop3 delta.wav?dl=0 So I suppose the current performance of Deltawave is such that when two bits of sound shot thru the analog world should be about as close as the noise varies over time, that Deltawave can line them up and show such is the case. Or almost.
  7. I like the drift being shown this way before correction better than the linear drift line used previously even though you are still using the overall linear drift in the function of the program. The error distribution looks nice, but I'm at a loss as to how to make use of it or what it shows that would alert me to some issue. I suppose if it were badly messed up it might alert one to be suspicious of the results.
  8. Yes, no pattern seems to repeat now for drift that are related to the musical content. I also notice when I HP at 20 hz there is no music only noise left when comparing loopbacks taken a few minutes apart. While also getting low numbers loopbacks done a week apart do have a little music left among the noise. So apparently a very small amount of drift difference done days apart. If I leave off the HP filters there is a bit of residual music at low levels in the noise. So all in all I think the change to leave off phase values in or below the noise floor was a positive improvement.
  9. Give a bit to look more closely. It looks like no pattern at a glance. Also on loopback vs loopback though values were good before you could hear music clearly in the noise previously. It is gone now. Makes me think the matching is better as the noise level is just as low, but music isn't heard even with 95 db of gain. Well this is if I use a 20 hz high pass filter.
  10. Okay just a quick look. For files with no options turned on it looks like difference results are regularly about 1 db less good. Null depths are a few db less good. As for doing filtering before vs after I'm not seeing much if any difference just as you said. The timing drift does seem to show more variable results on loopbacks vs original. Results do seem several db better on loopbacks vs loopbacks where result are -100 db or better for difference and some really impressive null depths. The gain error seems very useful for this. It shows where there is more error vs others. So you can snip it off and improve the results. I wonder about this correlated null depth.
  11. So can you fill in details about the HP and LP start, end and start/end filtering?
  12. Maybe to the de-blurred applause of one hand clapping?
  13. I'm pretty sure the reason some of these nulls aren't better is down to phase. If things aren't DC coupled or like Miska mentioned made to work to a very low response of having the low corner at 2 hz or less they'll have some phase shift on the low end. You'll have some phase shift on the high end from digital filtering at 44 khz rates. You can have low noise, low distortion, and still with a little phase shift nulls will be decreased. That is why when I compare a pair of loopbacks that were taken at different times they will null better than 100 db, but from one generation to another you are doing good to get near 70 db. The loopbacks compared to each other have both seen the same amount of phase shift at both ends of the spectrum. Now having said all that I'm not convinced these phase shifts make much of a difference we can hear. I prefer it not be there however.
  14. Here is the same file showing a similar pattern with -20dbFS 5 hz tone added. The amplitude of the drift is now much much higher though showing the similar pattern. So it looks like phase issues at lower frequencies can trip up Deltawave on drift calculation even enough to lower the null depths. Well actually when gear messes up phase it actually is a less well nulled result. But in a perfect world you'd get a lowered null without mistaking low frequency phase for increased drift.
  15. Yes I was aware of that which is why I thought high pass filters might be causing these effects. I would think the drift difference isn't in the signal itself, but in the way it effects drift calculation in software.
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