Koz wrote:
That’s the preferred method.
It depends on the use case.
Normalize will certainly work, however to say that a highpass will introduce clicks and noise, is not always correct.
In the case of the OP, he would most probably remove DC from the whole file anyways.
In that case, a highpass may actually help reduce thumps due to DC discontinuities.
Plus VHS ain’t exactly hifi, so attenuating (highpassing) frequencies below 50/60 Hz (PAL/NTSC)
will actually be beneficial with some recordings, to get rid of field/frame scan noise that sometimes
plaques VHS recordings and playback.
Likewise, there ain’t much above 14 KHz, so a lowpass filter will reduce potential line noise.
(15.625 KHz for PAL and 15.750 KHz for NTSC).
Note however, filters do have limitations, and one of them is phase delay and can cause peaks.
However, it’s nice to have options, depending on use/application.
Since Audacity is used for so many different applications, the manual method can be put to another use,
i.e. generating complex waveforms for step and impulse response testing of audio/analog circuits using spice simulations.
(Note that the spice simulator will not play the wav file through the “normal” output, but rather apply it to the circuit).
You can create crazy waveforms like such:
(Just don’t play them through your speakers or headphones, export as a mono wav and use it as a step source in your simulations).
By using high sample rates (192 KHz), you can create short pulses with a resolution of around 5uS.
That is nearly a line synch pulse width for good old analog video.
The slew rate will also be pretty darn good, so any skewing/undershoot/overshoot you see in the simulation,
will be from circuit under test.