When activated, decay time temporarily rises to infinity, making the signal recirculate indefinitely inside the reverberation engine. This is best suited for one-off special effects such as “deep-freezing” audio material, or if you’re looking to create something a little less conventional than a fade-out for the end of your track.
Simulates the frequency-dependent absorption of air, where high frequencies rolloff quicker than low-frequencies with respect to distance. You’ve most probably noticed this real-world phenomenon when you’re far away from a concert venue and only able to hear the bass, and gradually start to hear the whole mix as you get closer.
Scales the modal density with respect to the current setting, which is internal to the plug-in engine, and depends on other parameters such as reverberation time, etc. The modal density governs the frequency “smoothness” of the verb engine. Increasing this setting reduces the graininess of the reverberation. Adjust to taste, depending on the source material and desired result.
Roll-off frequency for the air absorption simulation. Signal content above this frequency vanishes faster.