This version (18 May 2021 08:58) was approved by John Joseph.The Previously approved version (05 Jun 2020 11:08) is available.Diff

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Limiter With Hold


The LimiterWithHold block computes the RMS level of the incoming audio signal and attempts to prevent it from exceeding the threshold by automatically reducing its gain. Hold controls the rate of the time limiter will respond to change in input signal.

Targets Supported

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



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Input0AudioInput channel0


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Output0AudioOutput channel0

Configurable Parameters

GUI Parameter NameDefault ValueRangeFunction Description
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RMSTC_Channel<n> 5 ms 0 to 10000 ms Controls the tracking rate of the RMS-approximation calculation used to track the input level.
Decay_Channel<n> 5 ms 0 to 10000 msControls 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
Hold_Channel<n> 0 ms 0 to 2000 ms Controls the time the limiter maintains its current gain before it starts new gain as the input level changes
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
NumChannels120Number of input and output channels. Change in this value requires re-compilation

DSP Parameters

Parameter NameDescriptionADSP-214xx/SC5xx/215xx ADAU145x/146x
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RMSTC_Channel<n>Time constant for RMS calculationFloat 8.24 format
Decay_Channel<n>Decay valueFloat 8.24 format
Hold_Channel<n> Time to resopond the limiter to change in input levelFloat 8.24 format
Threshold_Channel<n>limiter thresholdFloat 8.24 format

*Note: <n> → indicates channel number

DSP Parameter Computation

Decay = 1/P^(1000/(Decay * FS))
Hold = FS * HOld/1000
Where P is 1/9 and FS is the sampling rate

Where FS is the sampling rate

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