I'm getting some strange crackle in my ultra-sound signal, with a spacing of around 130 to 190 ms. I checked all sorts of things and can't find the culprit. It must be either an electrical problem or something of the DAC/ADC. Anyone have any ideas...?
(Depicted is 40 kHz signal, where the disruptions are visible).
@sciss 1st: This looks awesome. Would be a great album cover or so...^^
2nd: what are you trying to do actually?
@nikita I'm trying to extract relative motion in front of an ultra-sound sensor, using standard audio DSP and a regular sound card running at 96 kHz. Just found the probable culprit of the spikes - the ADC or anti-aliasing filter in my sound card (using a different one worked)
@sciss For what use? Or just for fun?
@nikita It will be part of an audio-visual installation in an upcoming exhibition. There is some rudimentary documentation https://www.researchcatalogue.net/view/432898/432899
@sciss sounds really cool!
So I can clearly see the Doppler shifts, but those spikes are really annoying. I tested multiple channels and cable now, it's always the same. Will try a different audio interface today, but I'm not convinced that it would be the source of this behaviour...