4 Mistakes to Avoid When Compressing Vocals
I recently came across a great article by Rob Mayzes at The Pro Audio Files about vocal compression, and the common mistakes people make. The article simplified concepts that can often feel overwhelming. Since vocal compression is something I’m sure most of us could at least use a refresher on, I’d like to go over the concepts brought to light by Mr. Mayzes and include some of my personal experience as well.
The vocal sound you are trying to achieve will vary by genre, but a cornerstone of modern vocals is consistency in level and clarity. Most of us recognize a compressor as the solution to this problem, but attempting to achieve a modern, punchy sound with a single compressor can often lead to over-compression. This leads us to our first common mistake:
1. Relying on Compression Alone
Naturally, the human voice is dynamic and inconsistent, depending upon everything from what vowel is being sung to where a note lies in relation to the singer’s vocal range. Taking a beautiful, natural performance and creating a dynamically consistent performance while maintaining the character and life is our goal. Using one compressor to achieve this will most likely lead to over-compression. Instead, before placing a compression plug-in on the channel, manually apply some gain automation. Gain automation is when you boost or cut the level of the raw vocal file (not volume automation – volume automation would apply level changes to the overall track after the signal has gone through your effects chain). This creates consistency in the performance before any plug-ins touch the signal. See the video below for a more in-depth explanation of gain automation:
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2. Using Only One Compressor
This is a simple concept, and it can make a huge difference in the sound you want versus the over-compressed, lifeless sound you don’t. Experiment with two or three compressors throughout your vocal chain. To start, a slow compressor with 2-3 dB gain reduction, a ratio of 1:1 or 2:1, attack time between 5ms – 30ms (lower values produce a thick, heavy sound while higher values are punchy and aggressive), and a medium release time of about 50ms. Rob Mayzes suggests to adjust the release time until the compressor breathes with the tempo of the track. This first compressor is to achieve tonal compression and to apply light dynamic consistency. Then apply a second compressor to really tighten up the dynamics. Try a gain reduction of 2-3 dB again, but apply a faster attack time and higher threshold than your tonal compressor to capture those loud transients. The order of your compressors is not set in stone, experiment with the order and observe the results.
3. Only Applying Compression Directly to the Channel
Now to really keep your vocal up front of the mix on every word, you’ll need to apply parallel compression. Place a HEAVY compressor on a return track and send your vocal signal through that channel. On the return channel you want every word to be at almost exactly the same volume. When soloed, it won’t sound right at all, but this is only meant to be a layer in your vocal mix. Bring the return track to 0 dB and boost until your vocal starts becoming louder. Leave the volume there or bring it down, again this is only meant to be a layer.
4. Using Super Fast Attack Times
Squashing the transients with a fast attack time will push your vocal farther back into the mix. Generally, an attack time above 2ms should allow the transients to cut through, but if you find your vocals sounding squashed, try adjusting your compressors’ attack times. The “squashed” effect can be useful with backup vocals however, and can help to separate them from your lead vocals.
These are all general guidelines – as with everything in production and mixing, experiment and find what works for you!