Sound & signal
Threshold
Threshold is the level above which a compressor or limiter starts working. Below it nothing happens; above it the processor reduces gain by whatever the ratio says.
In practice
Threshold decides how often it acts. If everything crosses it, you have simply made the record quieter and flatter.
Set it so the loudest moments engage the processor and the rest of the track passes untouched — you should see gain reduction on peaks and nothing between them. If the meter never returns to zero, the threshold is too low. On a club mixer this is rarely a control you should be reaching for at all: the venue is already limiting downstream, and adding your own stage of it removes dynamics the system was going to remove anyway.
Peaks only
What should cross it
Back to zero
Where the meter should return
Downstream
Where the real one lives
Where these come from: Standard dynamics practice and club system behaviour — technique, not catalog figures. For what we can measure, see which processor you are setting.
Why it matters
It is the control that decides how often the processor is doing anything at all, which matters more than how hard it works when it does. A threshold set low enough that everything crosses it produces constant compression, and constant compression is just a quieter, flatter record.
In a club the threshold that actually governs your night is not on your mixer — it is in the venue’s processor and its limiter, set by an installer against the speakers. Everything you send is being measured against a number you cannot see and did not choose.
Frequently asked
Where should I set the threshold?+
So only the loudest moments cross it and the gain-reduction meter returns to zero in between. A meter that never returns means everything is being compressed, which is just a quieter record.
Does a club system have a threshold?+
Yes, in its processor and limiter, set by whoever installed it. You cannot see it or change it, and everything you send is measured against it.
Is a lower threshold more compression?+
More often, not harder. How hard is the ratio; how often is the threshold. Both matter and people usually reach for the wrong one.
Related terms
Ratio
Ratio sets how hard a compressor reduces anything above the threshold. At 4:1, four decibels of input above the threshold become one of output. At 20:1 or beyond it stops being compression and becomes limiting.
Attack and release
Attack sets how quickly a compressor responds once the signal crosses the threshold; release sets how quickly it stops once the signal falls back. Together they decide whether you hear the processor or the music.
Compressor
A compressor reduces the level of anything above a threshold, narrowing the gap between the loud and quiet parts. The result can then be turned up as a whole, which is how records get their density.
Limiter vs compressor
Both reduce dynamic range. A compressor turns down loud signals gradually by a ratio; a limiter stops them passing a ceiling at all. A limiter is a compressor with an extreme ratio and a fast attack.
Explore: LUFS meter · Compressor · Limiter · All DJ terms