Thank you for the post. For Bluetooth and SoundTouch sources we have a video HERE explaining how to add additional systems, like your SoundTouch 10. If your system is up to date with our latest software, we also have a wired input rebroadcast feature that's currently in Beta. Where you can send any source connected to the 650 to additional systems. To do this, get the source you want to listen to playing on the 650, click on the system in the system tray at the bottom of the SoundTouch app and add your ST10 to the group. We have an article about this feature HERE.