Mac storage basics · Photos, music and video
Can I move Logic Pro's sound library to an external drive?
Short answer: Yes. In Logic Pro choose Sound Library → Relocate Sound Library and pick a folder on the external drive; keep the drive connected when you use those sounds.
Yes — Logic Pro has this built in. Choose Logic Pro → Sound Library → Relocate Sound Library… and pick a folder on your external drive. Logic moves the content and remembers the new location; keep the drive connected when you use those sounds.
You can also review which content packs are installed from the same Sound Library menu and remove ones you don't use. GarageBand downloads its own sound packs as well, which you can manage from within the app.