Link won't open for me.
As a camera repair guy, most of these ideas, using audacity for example, don't work for focal plane shutters.
What is often not understood is that there are no shutter speeds. There is only one shutter speed and it is the difference between when first curtain open and when second curtain starts to close, that actually controls now much light gets to the film
First curtain opens, fully exposing the fillm, flash fires and the second curtain closes. This is flash sync speed. E.g. 1/30s
for 'faster' speeds, first curtain starts to open, but when it has travelled half way across the gate, the second curtain follows it to close. So you just get a slit of liight passing across the film. This is 1/60s
For 1/125s, second curtain starts to close when first curtain has travelled a quarter of the way. 1/250 an eighth and so forth.
The curtains always travel at the same speed.
Now, both curtain have to travel at the same speed. If second curtain is faster, it can catch up to the first and cause shutter blanking. Curtains travelling at different speeds will cause uneven exposure across the frame.
Look at my thread on here, build a cheap shutter tester that works.