Symphony I/O: Using Soft Limit

Using Soft Limit

Soft Limit is Apogeeʼs proprietary analog process for taming transients before A/D conversion. By gently rounding transients in a transparent manner, itʼs possible to maximize level BEFORE the A/D conversion stage. 

Soft Limit Settings

Soft Limit may be engaged on each analog input in Maestroʼs Input tab window. The following settings are available:

  • -2 dBfs - Soft Limit begins to attenuate transient peaks at a level of -2 dBfs. This is the most transparent Soft Limit setting.
  • -4 dBfs - Soft Limit begins to attenuate transient peaks at a level of -4 dBfs. This is the threshold of previous implementations of Soft Limit.
  • Soft Saturate - a lower threshold, plus asymmetrical clipping in a manner similar to tube circuits.
  • Soft Crush - The most extreme setting, where audible distortion and dirty mojo are required. Take that, drums!

  Soft Limit on the 16x16 Analog IO Module: On the 16x16 Analog IO Module's inputs, soft limit functionality is restricted to On and Off. The On setting corresponds to the -4 dBfs setting on other IO Modules.  

When to use Soft Limit

Soft Limit is an analog process that instantaneously rounds transient peaks; for all intents and purposes attack and release times may be considered instantaneous. As with any peak reduction device working at such fast time constants, Soft Limit is most effective with signals whose peak information is much greater than its average (or RMS) information, such as drums, percussion and plucked instruments. Soft Limit may not be the appropriate choice for limiting signals whose crest factor (peak to RMS ratio) is low, such as bass or organ.   The two more radical settings, Soft Saturate and Soft Crush, are intended to be used as creative effects rather than subtle control of digital overs. Throw caution to the wind, set Soft Limit to Soft Crush, Input Analog Level to Variable, and push up the slider until your signal is warm and crunchy!