Roon Labs’ RAAT technology enables synchronized multi-zone playback across multiple platforms including Mac, PC, Linux, iOS, Android, and Roon Ready devices. 

When playback begins, the Roon Server must first determine the current “clock” position on each zone in order to synchronize the start of playback. 

On occasion, Roon Ready devices running Android fail to properly report their clock position, resulting in out-of-sync playback. This behavior is caused by the underlying implementation of the Android operating system and affects all applications.

The Following Devices are affected:

• All Android Phones and Tablets running Roon Remote

• Astell&Kern SP1000
  

• Astell&Kern SP2000
  

We've worked with our partners to get Roon Ready grouped zone playback synchronization working as reliably as possible on these devices, but we’ve determined that it’s not possible to make them synchronize perfectly every time due to these underlying issues with the Android platform. We will continue to work with our partners to explore future improvements in this area.