Each zone preset can have its own fade time set. This affects the music level and all microphones for that Zone. When a preset is recalled, the levels will visibly jump to the new target level, but the audio will fade to that final value in the time set, which can be up to 60 seconds.
Source selection change will also cross fade giving a smooth transition between different sources.
To access this feature, presets must have been previously created and saved. You can then access the Fade Time by navigating to Zones from the WebApp home page, select the zone you wish edit and click on Presets in the top right.