Volume increase of a magnitude spectrogram Let's say I have an audio waveform and I perform an STFT on the waveform and then take the absolute value to get the magnitude spectrogram.

Is there a transformation that I can make to that spectrogram that would produce the same result as taking increasing the volume of the original waveform and recomputing a magnitude spectrogram?

Is it as simple as multiplying all the bins by a constant?
Yes. The DFT/FFT is a linear function of the audio waveform, and taking the absolute value does not break the proportional relationship.

-k