Given that @pkane is here and wrote the software that made this possible, I thought it good to post up here too. I'm a zero-view "youtuber" who actually only posts up videos there as an outlet for talking about fun technical topics that few actually care about (which is all to pointed an analogy to my day job as a research professor...).
I've wanted to use the Null Test as a way to help people get their heads around what may or may not be audible and DeltaWave is just an incredible tool to be able to do that. Massive props to @pkane for writing it. I've played enough to start to get a handle on its limitations (doing negative controls by testing a device against itself typically) and therefore to put a pair of videos up. Part 1 goes over the concept of the Null Test (I go back to the Carver Challenge days -- I'm old) and uses DeltaWave to calculate the difference in USB-USB vs. USB-BlueTooth or USB-Airplay. What I love about being able to have a video on it is being able to play the original clip and, without changing levels, play the delta. Masking will have us hear less than the delta shows, but when that delta is so, so quiet, it really drives home what the difference really is.
Part 2 then takes it to DACs, comparing a cheap dongle (JCally JM6 Pro) vs. an "entry level" desktop DAC (Modi+). My rig is going to be a limiting factor here, but even with the limit of maybe 105 dB or so of SNR, it, to me, drives home the point. If we're nulling out at 100 dB, you're not hearing that. Listening to the difference signal and hearing nothing -- boosting it like crazy and having the delta be still dominated by pure noise -- to me, really drives home the point in a way that a plot can't (again, I'm a scientist by day -- I love plots). The start of Part 1 there, though, also hits an old informal experiment on the audibility of distortion which, again, is humbling for those that chase SNR levels in the triple digits.
I've wanted to use the Null Test as a way to help people get their heads around what may or may not be audible and DeltaWave is just an incredible tool to be able to do that. Massive props to @pkane for writing it. I've played enough to start to get a handle on its limitations (doing negative controls by testing a device against itself typically) and therefore to put a pair of videos up. Part 1 goes over the concept of the Null Test (I go back to the Carver Challenge days -- I'm old) and uses DeltaWave to calculate the difference in USB-USB vs. USB-BlueTooth or USB-Airplay. What I love about being able to have a video on it is being able to play the original clip and, without changing levels, play the delta. Masking will have us hear less than the delta shows, but when that delta is so, so quiet, it really drives home what the difference really is.
Part 2 then takes it to DACs, comparing a cheap dongle (JCally JM6 Pro) vs. an "entry level" desktop DAC (Modi+). My rig is going to be a limiting factor here, but even with the limit of maybe 105 dB or so of SNR, it, to me, drives home the point. If we're nulling out at 100 dB, you're not hearing that. Listening to the difference signal and hearing nothing -- boosting it like crazy and having the delta be still dominated by pure noise -- to me, really drives home the point in a way that a plot can't (again, I'm a scientist by day -- I love plots). The start of Part 1 there, though, also hits an old informal experiment on the audibility of distortion which, again, is humbling for those that chase SNR levels in the triple digits.
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