Traditionally, recording studios have been built round the mixer, the multi-track recorder and
various ‘outboard’ signal processing units. Digidesign has invested most of its development
effort on recording and mixing, rather than signal processing. Nevertheless, realizing the import-
ance of the signal processing equipment, Digidesign had the good sense to create a software
’plug-in’ system and then encouraged third-party developers to create software ’modules’ which
can ’plug-in’ to Pro Tools systems to provide this ’outboard’ signal processing.