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Old 12th April 2009
Using the Logic Pro Compressor as a De-Esser

Using the Logic Compressor as a De-Esser
This has also been posted on Logic Pro Help :: Logic Pro Forums in this thread: Logic Pro Help :: View topic - Using the Logic Compressor as a De-Esser

What and why
The bundled de-esser in Logic Pro is not that good for vocals. Since it can't function in wideband mode it tends to make the vocal lisp very quickly.

This preset does a much better job in my opinion though it's built on a very simple technique: using a resonant high pass filter in the internal sidechain of the Logic compressor.

How to use the preset during mixing
1) Solo the vocal track and loop a couple of bars. Find a part that contains lots of sibilance ("s" and "t" sounds).
2) Switch the Activity parameter from "On" to "Listen", and tune the Frequency parameter until the sibilance is worst. Switch Activity back to "On".
3) Lower the threshold parameter until the compressor ducks on sibilance but not during the rest of the vocal. This is very important to avoid overdoing it.
4) Adjust the ratio if necessary to make the ducking less (lower ratio) or more agressive (higher ratio). The default ratio of 10:1 is fairly aggressive but sounds great.

How to counter a wide sibilance area
Normally a sibilance problem occurs within a specific area, e.g. around 7 kHz. If you're having problems with both "sss" and the lower frequency "chh" sounds then try lowering the Q value. Go from the preset default of Q=5 to around 2 or even lower. Do this while in the "Listen" mode in step 2 above. You need to re-adjust your threshold after doing this.

Where to insert a de-esser
Insert a de-esser early or first in the vocal chain, before equalizing or regular compression. This will give you the most natural sounding result.

However, if you're boosting lots of highs in your vocal eq then you may get better results by inserting the de-esser after the equalizer but still before regular compression. You need to re-adjust your de-esser threshold when doing this, and you could possibly be getting a few more "false positives", i.e. ducking on normal parts of the vocal.

Nerdy stuff you can skip
I've chosen a high pass filter and not a parametric eq in order to detect from the specified frequency and upwards, though it focuses on the specified frequency due to the resonance caused by the high Q value in the filter. The best of both worlds then.

Since the compressor works in wideband during the actual ducking you won't get the lisping artifacts associated with many splitband de-essers. But it also means this de-esser preset is most useful on vocals. If you're trying to remove a fret noise in a guitar recording you may want to use Logic's own de-esser plug-in.

Download and install
Links | Audio Articles, Technical Tips, Download Presets

Move the de-esser preset (.pst file) to this location:

Mac HD > Users > YourUserName > Library > Application Support > Logic > Plug-in Settings > Compressor

Audio examples
Original vocal without de-essing

Same vocal with de-essing preset
Notice how the "s" and "t" sounds are more controlled and lower in a pleasant way without lisping, and the rest of the vocal is untouched.

Using the original vocal WAV file clip you can experiment with the preset yourself. The WAV files are included in the above ZIP download.