Building something like the Ableton Live Gate device

#1

I want to have something similar to this device and believe should be fairly simple.

This is how I would explain this (simplified) device: Audio is only passed through if it's above the given threshold. Amplitude is dependent on an AHD envelope.

I know how to do the envelope part but failed to find a way to get a trigger for the threshold.

#2

Well, I managed to put something like it together. Sound is very distorted though

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#3

You could add a smooth with rise and fall, these would be you attack an release.

Edit: I see you use an envelope for that...

#4

What do you mean "very distorted" ? I am assuming it's audio rate clicks from rapid vca triggering?

My first guess is that it has to do with the live input from the envelope follower producing a very jagged output. Try a smooth object in between that and your math/> to see if that helps.

My other thought is that the bool output of math/> isn't putting out long enough trigs -- try a timer/pulselength on the output before going into the envelope.

2 wild guesses that may not help at all. :sweat_smile: Let us know how it works out!

#5

In Broadcasting and Studio scene these are called "Noise Gates" or "signal gate" and are used to remove (gate("gate out") background noise or ambient noise in a audio broadcast. Typically they are a Envelope follower that is run into a comparator that produces the gate when the threshold is reached. This gate is then sent to an envelope generator to turn on the original sound run through a VCA. The envelope generator's adjustments (primarily the release or decay) allow the sound to last longer (and allow more of the noise to happen) and are adjusted depending on the program material. If the sound has a long decay, it is set longer on the EG.

Distortion happen often if the envelope follower doesn't slew enough and low frequency sounds in the original cause the comparator to fire multiple times and this makes a chopping sound.

#6

Hey ya'all. Thanks for your answers!

That was one good history lesson Ersatzplanet :slight_smile: I will refer to them as noise gates from now on. It's also exactly what I am using them for.

Using math/smooth worked out just fine.

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NoiseGate.axp (3.5 KB)