Technical Editor, Sound On Sound... (But generally posting my own personal views and not necessarily those of SOS, the company or the magazine!) In my world, things get less strange when I read the manual...
Real DC offsets rarely exist these days (though it was a real problem with my first soundcard 30 years ago).
All you are seeing is another example of an asymmetric waveform. Vocal waveforms are often asymmetric. Try zooming in and you'll see large short positive going spikes with the waveform just below zero for the rest of the time. Different vocal sounds will show different amounts of asymmetry.
Right, okay, Also, this may be interesting to you, but I may have told a little porky pie, by omission... that recording is heavily processed, and in the signal chain is an ffmpeg highpass filter (set to 65hz) I always thought their highpass added a significant but hard to describe artifact to the sound, kind of phasey. Well i took it out of the signal path and my waveform is now looks much more symmetrical - well what you would expect
dfira wrote: ↑Wed Nov 24, 2021 1:28 pm...in the signal chain is an ffmpeg highpass filter (set to 65hz)
A high-pass filtered signal can't have a dc offset, by definition, since dc is 0Hz and won't get through the filter!!!
always thought their highpass added a significant but hard to describe artifact to the sound, kind of phasey.
The steeper the filter, the greater the phase shift. That can be audible, especially with acoustic instruments.
That phase shift will affect the phase relationship between fundamentals and harmonics, and that will often change the shape of the waveform significantly.
Technical Editor, Sound On Sound... (But generally posting my own personal views and not necessarily those of SOS, the company or the magazine!) In my world, things get less strange when I read the manual...
