We often think of compression as being one of the most important mixing tools we have at our disposal along with EQ and deservedly so. Compressors work by reducing dynamic range and making our audio sound like it has more energy behind it. Like with any plugin in our tool belt, if we run a compressor too aggressively, we kill the dynamic range altogether. Let’s talk about what dynamic range in audio terms is and why it’s so important to our individual tracks and max as a whole.
What is Dynamic Range in Audio
Dynamic range in audio refers to the difference between the quietest and loudest points in our audio. Note that this is the difference between the PRACTICAL extremes on the top and bottom end of our audio; I’m not referring to the noise floor.
This is just the dynamic range between the extremes for the audio we want people to hear on that track.
Here is an illustration of the waveform of a vocal track to actually demonstrate dynamic range in audio.
The absolute peak of the vocal tops off at -6dB whereas the quietest practical instant of that track we want our listeners to hear as part of that audio tops off at -20dB.
This creates a difference of 14 decibels between the two, which is our dynamic range for this vocal track.
That peak of -6dB is the product of the vocalist having to belt and push their voice to hit a much higher note relative to the rest of the melody. Whether it’s what the vocal melody calls for in terms of intensity or just that extra air and power which are required to hit that note, you naturally get these surges in the waveform relative to the average which is much closer to the -20dB nadir.
A difference of 14dB means that you’ll need compression to achieve a more average level with LESS dynamic range.
This is because, if left alone, the track will be impossible to set the correct level for. The loudest parts will be too loud in the context of the mix, and the quietest parts will be buried and lost in the context of the mix.
While you can automate the volume of the track, compression is more practical for achieving a more average level. Dynamic range compression brings down the peaks via that compression, then it brings up the rest of the volume via makeup gain.
Why Dynamic Range in Audio Matters
While we want to reduce the dynamic range in our audio, we don’t want to compress to excess.
In other words, we don’t want to use too extreme a compressor ratio combined with too low a compressor threshold which will effectively reduce the dynamic range from 14 decibels to next to nothing.
As you can see, the higher the ratio, the more the output level of anything which gets compressed via the threshold gets output at the same level. The waveform of the audio itself gets flattened similar to the line with the higher ratios as virtually the entire track has the same peaks as a product of that output level.
This is how we get those fat sausages of audio which are the illustrated void of dynamic range – the volume never changes.
Practically speaking, this manifests as being extremely exhausting for the listener’s ear.
This is why dynamic range is important to keep intact in your audio. Not only does dynamic range sound natural and conversely a void of it sounds UNNATURAL either in a track or a mix, it keeps your listener engaged as you get variations in the volume range, particularly on a mix level where different tracks assert themselves at different times.
Unfortunately it’s on the all important mix level that dynamic range is usually sacrificed at the expense of attaining a louder mix in order to be competitive with contemporary releases.
A mix is run through a limiter so that the dynamics of the loudest peaks are squished down so everything can be turned up, resulting in an overall and more consistently louder mix, also resulting in that boring audio sausage.
I see this all the time when clients submit mixes for me to master. Thankfully I’ve put together a list of things you can do to get louder mixes without sacrificing the natural dynamics of your song.
