Remove Silence from Regions: Physically Gating your tracks in Logic Pro
Let's face it: gating a track with a nice and easy plugin is the laziest, and sweetest way to clean up a recording when producing music.
It just feels great to fix those toms gating out the silence with a plugin and never thing about it again.
Briefly, a gate is a device which silences a track when its level is below a set threshold. You can set multiple parameters such as the attack, sustain and release of such device, controlling how it will cut off the signal. And you can also set how much you need it to lower the signal, from a couple of dBs to full silence, making it a very useful and powerful tool to tidy and clean up your mixes.
Sometimes, however, we need more precise control over what we are are gating, or, perhaps, something that physically cuts away the unwanted noise from your regions in your DAW.
In Logic Pro there is a function called "Remove Silence From Audio Region" that does exactly that: you can set some parameters for the purge and then let it slay out the un-needed parts from the track.
The advantage of this method is that, firstly, you can see how it will affect the region you are processing, and secondly, you can then come back afterwards and tweak individually any bit that this process left untouched.
Here's how to do it:
1 - Select the region you want to process
This needs to be an Audio Region, obviously. You can see it's audio if a waveform appears on the region.
2 - Right click on it and select Split > Remove Silence From Audio Region
You can also go Functions > Remove Silence from Audio Region, in the 'Functions' Menu of the Arrangement area (where you see all your regions).
3 - Set the processing behaviour
A new Window will pop up, showing waveform of the selected region. The boxed bits are the sliced parts that will remain after the processing.
Here you can set a few parameters, such as:
Threshold: Set the level below which the audio will be removed. Sometimes it might be easier to work on smaller parts of the region instead of the whole track, in order to have a better visual on your slicing boxes.
Minimum Time to accept as silence: This defines the minimum amount of time it needs to pass before the system detects a silence (under-the-threshold-bits) as a removable part. This is very handy to avoid removing very short slices between single peaks of the waveform.
Pre-Attack time: With this setting you can adjust how many milliseconds you want the system to leave before the slicing, meaning that you can retain the natural attack of the waveforms when chopped.
Post-Release Time: Same as above, but for the tail of the regions. This will avoid an abrupt cut of the tails as soon as the level goes back below the threshold.
Search Zero-Crossing: tick this box to make Logic slice the regions only on the nearest zero crossing point, which is the specific point in time where the waveform crosses the 0 level axis (silence) before completing or restarting it's cycle. This will avoid any click/pop that would be heard if the playback plays an audio signal starting in the middle of a peak (not in the 0 level axis point).
4 - That's it!
You can now tweak the sliced regions as you wish. It is advisable to add a very short fade in and out to them all, in order to avoid clicking and popping, selecting all the regions within the track, and setting the fade in and out to 1/2 ms within the region parameter box (Top Left)