W1 Limiter is a clone of Waves L1, with identical output, as well as an approximation of Waves L2. Waves L1 famous limiter (and thus W1 - for compatibility reasons) uses three times longer actual release time than standard RT60 metric. This means that if you set 50ms release in the limiter, it will actually yield with 150ms standard RT60 release time.
Different engineers recommend different values for release time, the default value is chosen reasonably to provide a smooth limiting for most typical usage of the limiter. If one is not experienced with limiters, it is recommended to keep the default release time.
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