M-Audio Radium 49 is a legacy "end-of-life" product that is no longer officially supported
Unsupported Systems: Any macOS from 10.11 El Capitan through the latest macOS 15 Sequoia is not officially supported. The Best Workaround: Using a MIDI-to-USB Interface
If it is grayed out, try creating a "New External Device" manually and connecting it to your interface in the software. m-audio radium 49 driver mac
Power: The Radium 49 still needs power. You can either plug its original USB cable into a USB wall charger or use a 9V DC 500mA power adapter. 3. Verify Connection in macOS
Class Compliance: Unlike newer Keystation models, the original Radium 49 is generally not considered fully class-compliant for modern systems, though some users have had success with workarounds. M-Audio Radium 49 is a legacy "end-of-life" product
The M-Audio Radium 49 is a hybrid device, but it is largely dependent on legacy drivers that are no longer supported by M-Audio or fully compatible with modern macOS architecture (Apple Silicon M1/M2/M3 chips).
The Bottom Line: M-Audio has discontinued support for the Radium series. You cannot install a manufacturer driver on macOS Catalina or newer. Connect the Radium 49 to an available USB-A port
macOS Catalina (10.15) and newer (including Ventura and Sonoma). Apple Discussions Recommended Workarounds