DC offset trickery

[steve]

@RS_RS

Doesn’t the contribution by edgar-rft to the thread referenced above expain what is going on? Surely the asymmetry of peaks above and below the axis is irrelevant to whether there is DC offset? What matters is whether the integral of the waveform over a reasonable length of time is nonzero

You’re absolutely correct. When you understand what is happening, then the behaviour is not surprising.

@RS_RS

The second graph, over a longer time period, shows patches of a waveform with DC offset mixed with some zero-offset silence, a combination I would be surprised to see in reality

but they do occasionally occur (though not as badly as my illustration), and cause a lot of confusion when they do.

I’ve been searching for a good “real world” example, and I’ve found one. It’s quite a nice trumpet sample that has no obvious clipping.
Try Normalizing this sample to 0 dB with “Remove any DC offset” enabled.

Also try the Nyquist DC offset tool from here (default settings): DC offset tool (plug-in) - #9 by steve