Reference 4 introduces zero latency processing and makes sure you get the latest developments in DSP-assisted monitoring.
After buying you will get all the info you need to set up Reference 4. All of your old profiles will work, so you can pick up right where you were. Your machine must have at least macOS 10.9 or Windows 7.
NB: After the release of Reference 4, no new features will be added to any of the older versions. Expect Reference 3 patches only to fix critical bugs.