- , _minimum_length (X_("silence duration"), true, "SilenceDurationClock", true, false, true, false)
- , _fade_length (X_("silence duration"), true, "SilenceDurationClock", true, false, true, false)
+ , _minimum_length (new AudioClock (X_("silence duration"), true, "", true, false, true, false))
+ , _fade_length (new AudioClock (X_("silence duration"), true, "", true, false, true, false))