Questions & Answers

Bug Fix: Universal Control ASIO drivers invert clipped audio

–1 vote
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asked Jan 25, 2018 in Classic Mixers by steigdg1 (320 points)

I was baffled when I recorded some vocals from my StudioLive 16.0.2 into Cakewalk Platinum which were recorded a bit hot, clipping at times.  It wasn't obvious in the monitors while recording, but in playback there was this horrible ripping sound at the clip points.  Looking at the waveforms I could see that when the waveform hit the rail (call it +1 or -1), the sign of the signal shifted so that instead of being cropped at +1, it would ride the -1 rail instead, and then once it left the rail it instantly shifted back to just under +1.


I did some experiments using my Firestudio Mobile and was able to reproduce the problem - see attached picture.  It seems that the ASIO driver is negating the value of the signal when it hits the max value, which is so much worse than just clipping.  The top waveform in the image shows that the clipping is normal for the WDM/KS driver - just truncating the waveform.  The other two waveforms show two different releases of the Universal Control (1.7.4 and 1.7.7) and you can see at each clip point the waveform goes between +1 and -1 instantly. .

This sounds like something I have seen discussions of in the past, 'invert clipping', but all those threads seem to have been removed. This is a really bad bug, I would just use the WDM driver but my 16.0.2 turns into a 8.0.2 using any of the other drivers.Display showing 'invert' clipping in ASIO driver

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