Peak Limiter

The Peak Limiter object is used to prevent a signal from exceeding a specified peak level.  It is often used in professional sound systems before the system outputs to prevent clipping in the digital-to-analog conversion stage or to prevent potentially damaging sound levels from reaching power amplifiers and loudspeakers.  When the input to the Peak Limiter exceeds the threshold, the Peak Limiter will reduce the volume of the signal instantaneously so the output does not exceed the threshold.  A 1ms look-ahead feature is available which allows the Peak Limiter to limit the audio more transparently, at the slight expense of some additional latency through the block. When the Peak Limiter is selected from the Object Toolbar, an initialization dialog is produced.

Channel Count sets the number of channels of the Peak Limiter object.  A Custom setting allows the number of channels to be set to any number between 1 and 32. Channels are ganged in the sense that all channels share the same settings, but limiting is applied independently and with no interaction between channels.

Selecting Enable Look Ahead Delay will enable the look ahead feature for more transparent limiting, at the expense of 1ms of additional processing delay through the object. This additional processing delay will be accounted for in the Delay Equalization phase of compiling. Leaving this option clear will result in no look ahead and the standard processing delay. In this mode, limiting is still instantaneous, but may introduce some distortion, as peaks are being handled as they occur.

A Peak indicator illuminates when the input signal is above the programmed threshold and/or when limiting is taking place (related to the Release Time setting). 

The Identifier is a user configurable name that can be used for channel identification.

Controls

Peak Threshold (dBu) sets the point above which the Peak Limiter will engage and attenuate the signal level so the output does not exceed the threshold. 

Release Time (ms) sets the time it takes for the level attenuation to deactivate once the input level drops below the threshold. This can be can be set between 1ms and 10,000ms. The attack time is not shown in the control dialog because it is instantaneous.  

The Bypass button allows for easy comparison of the limited signal with the original.