Limiter

A brick-wall peak limiter that keeps the output from exceeding Threshold. Attack is instantaneous, Release controls how quickly the gain recovers, and Lookahead lets the limiter catch peaks slightly before they arrive at the cost of a fixed delay.

Library location

Library → Audio Effect → Limiter

Properties

Threshold (dB) (Threshold)

The output ceiling. Peaks within the lookahead window are reduced so the output stays at or below this level.

• Type: float
• Default: -1
• Animatable: Yes
• Range: [-60, 0]

Release (ms) (Release)

How quickly the gain recovers after a peak passes.

• Type: float
• Default: 50
• Animatable: Yes
• Range: [1, 5000]

Lookahead (ms) (Lookahead)

How far ahead the limiter looks to catch peaks before they arrive. 0 ms keeps audio sample-accurate; higher values trade a fixed delay for smoother limiting.

• Type: float
• Default: 0
• Animatable: Yes
• Range: [0, 20]

Makeup Gain (dB) (MakeupGain)

Gain applied after limiting. The final peak can reach Threshold + Makeup Gain.

• Type: float
• Default: 0
• Animatable: Yes
• Range: [-24, 24]

Notes

• Detection is channel-linked: the loudest sample across all channels drives a single gain factor applied to every channel, so the phase relationship between channels is preserved.
• The default Threshold of -1 dB (rather than 0) leaves headroom against the master limiter that is always applied to the mix bus, avoiding double limiting.
• Beutl's inline audio graph has no delay compensation. With a non-zero Lookahead, the buffered tail at the end of a clip (or at edit points) is discarded, and the lookahead delay is not compensated elsewhere — keep Lookahead at 0 ms when sample-accurate timing and A/V sync matter.

Usage

Place the Limiter last in the chain to guarantee the signal never exceeds Threshold. Lower Threshold (or raise Makeup Gain) to push the perceived loudness up, and shorten Release for a tighter, more aggressive sound or lengthen it to avoid pumping.

Source

src/Beutl.Engine/Audio/Effects/LimiterEffect.cs