Bouce to wave in SFP

there is an option in the engine menu. If you are using drones and a daw, its like using any vst/au plugin

Sorry for the confusion, Ive never used the bounce option and thought it was in the engine (there is a bounce button but its greyed out for me)

However if you click on the Matrix tab in synfire

on the left hand side there is a button marked capture.

Next time you play the song it will save a recording in the same folder as the project.

Obviously as this only works if you are using the engine.

Did you also play your song as Blacksun said? After pressing the Capture button (and the button is red), you need to play your song. Once the playback has finished (or you have pressed the Stop button) you will find the WAV file in your project folder.