This version (18 May 2021 08:58) was approved by John Joseph.The Previously approved version (15 Jan 2021 04:23) is available.Diff

Click here to return to the Dynamic Processors page



The Limiter block computes the RMS level of the incoming audio signal and attempts to prevent it from exceeding the threshold by automatically reducing it's gain.

Targets Supported

Name ADSP-214xx ADSP-215xx/SC5xx ADAU145x/146x
—————————————- —————————- ——————————-- —————————-
Limiter B B S



————————————— —————————— ————————————————
InputAudioInput channel


———————————————— —————————— ————————————————————————————-
OutputAudioOutput channel
ActiveInactiveControlPin outputs 1 indicates the limiter is active and 0 indicates the limiter is inactive.This essentially shows if the input signal has exceeded the threshold or not. The number is an unsigned integer format
LimitingRatioControlValue representing the current gain factor being applied to the input audio signal

Configurable Parameters

GUI Parameter NameDefault ValueRangeFunction Description
———————————————- —————————- ————————————- —————————————————————-
RMSTC 50 dB/s 1 to 10000 dB/sControls the tracking rate of the RMS-approximation calculation used to track the input level.
Decay 12 dB/s 5 to 23 dB/sControls the rate at which the signal compression ratio will subside after the input signal level has dropped below the limiter threshold. Larger values result in longer decays, with 23 never recovering to the original gain
Threshold1 dB -24 to +24 dBSets the threshold point. If the input signal's approximated RMS level exceeds the threshold point, the limiter will apply compression in order to prevent the signal from exceeding that level. This threshold level does not need to be an integer; its resolution can be set in steps of less than 0.01 dB. A full-scale sine wave is a level of -3 dB, due to the RMS measurement

DSP Parameters

Parameter NameDescriptionADSP-214xx/SC5xx/215xx ADAU145x/146x
—————————— ——————————————————————————- ——————————————- ———————————————-
RMSTCTime constant for RMS calculationFloat 8.24 format
DecayDecay valueFloat 8.24 format
Thresholdlimiter thresholdFloat 8.24 format

DSP Parameter Computation

Decay = 1/10^(Decay/(10 * (FS + 0.000001)))
Where FS is the sampling rate

resources/tools-software/sigmastudiov2/modules/dynamicsprocessors/limiter.txt · Last modified: 12 May 2021 09:35 by John Joseph