Devices Page

Under the tab Device Descriptions you manage your collection of Devices. Devices managed inside an Arrangement are a part of that arrangement. They can't be used by other arrangements unless you copy them with Device > Save to Global Rack.

Devices managed by Audio/MIDI Setup are global. They can be used by all Global Racks and copied into Arrangements, Sketches or Libraries.

Saving Devices

Synfire automatically saves pending changes of all devices to disk. With the Audio/MIDI Setup window, you can also save a device manually with File > Save As ... to a different place.