Device Descriptions keep important meta-data for sounds

All internal sound generators, audio plug-ins (instruments and effects) and external MIDI hardware (synthesizers) are referred to as Devices. The term is also used as a short form of Device Description, because that is basically the only thing you deal with in order to set up devices for use with Synfire.

Device Description

A Device Description is a small file that contains meta-data about an actual device (synthesizer, plug-in, sampler preset), the Sounds it has to offer and how these are selected. In particular this meta-data includes for each sound:

Although all of the above can be set anew for every instrument in an arrangement as you go, we strongly recommend you create a Device Description for those sound libraries and synthesizers you will be using most frequently. Especially if Custom Controllers and/or Custom Articulations are involved.