Hi. I’m looking for an automatic effect that will make an audio clip a bit slower and faster depending on how loud a particular section of audio is.
Like, I’m looking for an effect that will slightly slow down the audio clip when the audio file plays a loud tone and speeds up as it gets quieter.
(Eg. If the audio is: at -15db it will be fullspeed, at -10db is will be a little slower, at -6db it will be even slower, going back to -10 it will start speeding up again)
Something that will have an adjustable Attack Time, Release Time, Threshold, and Ratio, just like a compressor.
I hope I make sense to you guys, its kinda hard to explain.
Through this, I’m trying to simulate: how an audio playback circuit (mostly used in digital toys) will slow down and speed up on a low battery depending on how much power/loudness is output to its speaker. With what I’m trying to do I’ll likely use 0.1 second attack, 1.0 second release, and threshold of approx -14 db
In fact, I HAVE tried that already. But, I find that it’s for one thing not bang time-accurate.
And secondly, I work around that by pre-slowing down the track by 500%, doing the timetrack, then putting the speed back to normal after saving. From there, I take like 10 minutes just to attempt to do this on 10 seconds worth of audio (approx. 50 points made), but I still don’t feel I’ve achieved the effect I wanted due to not doing an accurate job (its hard).
That’s why I feel I need something to do this job for me automatically.
and it would be difficult to automatically calculate the necessary timing corrections.
I think the way to do it would be to loop through short sections so that the timing drift (per section) is not significant.
Also, I think that the perceived quality could be improved by creating a smoother envelope that rides the peaks (see follow and snd-avg).
Do you have a lot of these to do?
How accurate does it need to be?
I had a quick go and it seemed to be pretty effective. I worked from left to right making the adjustments. I also set the tempo range so that the “Upper speed limit” was 100%.
Can you think of any other applications where this effect could be useful?