I would like to explain to you their basic difference with the Compressors.
When the Ratio of the Compressor exceeds 10:1 (meaning that it aggressively “chops off” the sound and doesn’t “forgive” the decibels that surpass the Threshold) then we can say that the Compressor plays the role of a Limiter.
A Limiter is nothing more of a Compressor with a really strict Compression Ratio. Whatever audio signal surpassing the Threshold it gets chopped off aggressively so we must keep an eye on our Gain Reduction.
There’s no written rule but you should aim not to exceed 3db Gain Reduction on a Limiter. The Limiter’s role is to cut the sudden peaks and not to apply a smooth compression.
Limiters With A… Maximizer Role
Many Limiters, like Fabfilter L in the above photo, can also play the role of a Maximizer. They are hybrids.
Normal Limiters have a Threshold. You compress the signal to create stable dynamics and then you can dial back the volume using the Make Up Gain.
The hybrids though work the other way around:
The threshold is locked at 0db. You use the gain knob and give volume to the signal. When you reach and exceed the threshold then you apply limiting.
This way… you also make the volume louder plus you apply limiting to the peaks. 2 birds with 1 stone!
These kind of Limiters/Maximizers hybrids are perfect during mastering. You increase the final volume of the whole song and also cut the remaining peaks that would may bother the listener.
That doesn’t mean that we can’t use Limiters on Mono Tracks though.
If you have a Mono Track with a vocal/instrument that was recorded so bad and no compressor can fix the peaks then you can easily choose a limiter to do the job!
A Second and… “Alternative” Use Of Compression
As we said, the main purpose of a compressor is to match the higher volume levels with the lower ones.
But music and sound is art. So if we can create a new sound or modify the existing sound using the compressor… Why not do it?
Music producers like to experiment and use lots of Gain Reduction with ultra high ratio (sometimes up to 30:1) just so that they can “squash” the signal and push the compressors to the maximum.
This “overuse” of the compressor forces it to add a characteristic sound to the audio signal. While the “rules” say do not over-compress, sometimes by experimenting you can achieve some wonderful sounds.
What I like to do when I want to experiment – but also want to make sure that I don’t destroy the sound by over compressing it – is to duplicate a track of mine and use all the crazy effects that I want on the 2nd track.
Then I blend the 2 signals together by adjusting the volume faders.
The Reason There Are Many Compressors
If you’ve ever wondered why there are many compressors out there since they do the same job then this is the answer: Some compressors have their own unique sound.
Also, some analog compressors don’t have every single knob that I showed you above. Companies create them their own way, with only the most important knobs (Ratio, Threshold, Release, Attack).
That’s the reason you come across thousands of topics on the internet “discussing” which compressor is better for vocals or guitars or bass…
From time to time you will end up creating your own favorite compressor list, no matter if it’s analog or a digital VST.