Definition
Limiter — A dynamics processor that prevents an audio signal from exceeding a set output ceiling, catching peaks and reducing them to ensure the output never clips, while increasing the perceived overall loudness.
Limiter Explained
A limiter draws a hard line that audio cannot cross. Set the ceiling to -0.3 dBFS and no matter how loud the input signal gets, the output never exceeds -0.3 dBFS. The limiter achieves this by aggressively compressing any signal that reaches the ceiling, squashing peaks with an essentially infinite ratio. The result is a louder overall signal because the loudest moments (peaks) are reduced, allowing the average level to be raised without clipping.
Think of a limiter as a compressor with extreme settings. While a compressor at 4:1 ratio allows some signal above the threshold, a limiter at infinity:1 allows nothing above the ceiling. The attack time on a limiter is typically extremely fast (often sub-millisecond) to catch transient peaks before they slip through. This aggressive, transparent peak control is what makes limiting different from standard compression.
The key parameters on a limiter are the ceiling (the maximum output level the signal can reach) and the input gain (or threshold, which determines how much signal gets pushed into the ceiling). Raising the input gain pushes more of the signal against the ceiling, increasing loudness but also increasing the amount of limiting applied. More limiting means more gain reduction on peaks, which at extreme levels creates audible pumping, distortion, and loss of dynamics.
How Producers Use It
The limiter is the final plugin on the master bus in virtually every production. Its ceiling is set just below 0 dBFS (typically -0.1 to -1.0 dBFS) to prevent the exported audio from clipping. The input gain is raised until the beat reaches the desired loudness. Modern streaming platforms normalize loudness, so extreme limiting for maximum volume is less necessary than it once was, but the limiter still serves as the essential safety net that prevents digital clipping in the final output.
For loudness maximization, the limiter works in conjunction with upstream dynamics processing. If the mix hits the limiter with extreme peaks (like an unprocessed kick transient), the limiter has to work harder and introduces more artifacts. Smart mixing practice involves taming peaks with compression and soft clipping before the limiter, so the limiter only handles the final 2-3 dB of gain reduction rather than 6-10 dB. Less work for the limiter means a more transparent, natural-sounding result.
On individual channels, limiters serve as peak protectors for specific elements. A limiter on a bass track prevents occasional loud notes from overwhelming the mix. A limiter on a drum bus catches unexpected peak stacking when multiple drums hit simultaneously. These channel-level limiters are set conservatively, engaging only on the loudest moments to prevent problems without constantly affecting the dynamics.
Battle Tip: Place a limiter on your master bus with the ceiling set to -0.3 dBFS. Push the input gain until you see 2-3 dB of gain reduction on the loudest sections. This ensures your battle entry is competitively loud without distortion. If the limiter is working harder than 6 dB, your mix needs more dynamic control upstream before the limiter can do its job transparently.