Quote Originally Posted by embeddedmz View Post
Does this mean updateLayout performs a second replot after the first one ?
When updateLayout leads to a different size for the plot canvas, then the content of the canvas has to be recreated from scratch. This is not exactly the same as what replot ( no update of the scale ticks/intervals ) does, but as the heavy operation ( recalculation of the spectrogram image ) is done twice you should definitely understand and fix the problem.

Uwe