When setting up parallel compression, it’s best to use an auxiliary send to run parallel to your original signal, on which you insert a compressor. With this compressor, compress the signal heavily before blending it back in with your original signal via the auxiliary track’s channel fader.
Real quick let’s discuss how parallel compression works - when parallel compressing, you separate your original signal into 2 and create one that runs parallel to it. On this parallel signal, you insert a compressor and heavily compress the signal, then blend it back in with the original.
The compressor you insert is typically a downward compressor, which controls peaks. With this compressor, you can achieve a cool tone, and greatly control dynamics, while blending in the exact amount you want.
Perhaps the simplest and most common form of parallel compression is to use the wet/dry or mix dial on your compressor. When you use the wet/dry dial you’re essentially splitting the signal into compressed and not compressed - the percentage you choose will determine how much compression blends in.
This is definitely the quickest way to parallel compress, but it has a lot of limitations.
You can use a bus or auxiliary send to create parallel compression, first create the bus and the auxiliary track - in Logic Pro X this track will be created automatically after creating the bus. Then insert the compressor of your choice and heavily compress the signal.
Once you’re done compressing, use the auxiliary track’s channel fader to blend the compressed signal back in.
With the routing of our signal in mind, we can create more unique and dynamic parallel compression by automating the last plugin in our chain. The bus we created to send the signal to the aux track is routed after all of our original track’s inserts.
So if we automate aspects of the last insert, we in turn control how the signal fed into the parallel compressor.
If you want to parallel compress the left and right channels separately, set up 2 sends - on both insert a utility plugin and pan the signal to the left and right respectively. Then insert your compressor of choice on both and compress the relative signals as you see fit.
Since the panpot on each channel comes after the inserts , we can’t simply pan the routed signal - as a result, we need to use the utility plugin to pan the incoming signal prior to compression.
Similar to left/right parallel compression, we can split the signal into mid and side and compress those channels separately. Again set up 2 sends, but this time use MSED by Voxengo to mute the side on one auxiliary track and the mid on the other.
Again insert the compressors on these channels and compress as you see fit, then blend these tracks in with the original.
New York-style parallel compression is a great way to get more control over your parallel compression - set up the tracks as you normally would and insert your compressor, but then insert an EQ. With the EQ, amplify or attenuate aspects of the compression to shape the sound.
You can also use this EQ pre-compression to control what gets compressed or to what extent it triggers compression.
Following the same concept created by New York-style parallel compression, we can set up more unique processing - for example, maybe we insert a low-level compressor after the downward compression. This way we control the dynamics both from the peaks down and noise floor up.
Or maybe add a saturator after the compression to add some harmonic distortion. There are lots of possibilities.
If you want to capture as much of your signal as possible when using parallel compression, use a compressor with a very short attack and very long release - additionally, use a soft-knee setting with a higher ratio. This way the compressor captures the signal as quickly as possible, and at lower levels.
Then the longer release blends the transients and other aspects of the signal together, creating a smooth compressed sound.