Legacy Quartet Guide for Intel and Apple Silicon Macs
Apogee Quartet models are compatible with Intel-powered and Apple Silicon (M1, M2, M3, etc.) Macs and Windows 10 and above.
For Apple Silicon Macs, this requires installing the Apogee Control 2 software which replaces the previous Apogee Maestro 2 app.
This can be downloaded here under Legacy Product Installers:
After installing, all settings will be adjusted in the Apogee Control 2 app.
Direct Monitoring in Apogee Control 2
Enable direct monitoring by changing the Headphone output to Mixer. 
Scroll across to the right in Apogee Control 2 to view all output channels.
Set the Routing under any pair of hardware outputs to be "Mixer 1" to enable direct monitoring. 
When set as Mixer, the inputs and software playback are routed through the low-latency Mixer in Apogee Control 2 > then directly to Quartet's Outputs.
You can adjust the volume levels and settings in Mixer 1 for both the input sources and playback channels that are sending audio to the output.
Known changes with Apogee Control 2 compared to Maestro 2:
-No onscreen pop up indicators when adjusting volume and input gain
-Control 2 does not support Logic Device Control for adjusting input settings (48v, input types) from within Logic.
-Mac keyboard volume control not functional
For Intel Macs the previous Apogee Maestro 2 app can be installed and used.
Quartet Firmware:
You can check Quartet's firmware when connected by opening System Information on your Mac. Under Hardware > USB > Select Quartet and check what number this shows by Version.
This firmware version should be 13.09
As long as this is correct no future update is needed.
If Quartet's firmware is outdated, you can update it using the Quartet Firmware updater app included with the Apogee Maestro 2 installer. This process requires an Intel Mac, and we suggest performing the firmware update on macOS 10.15 Catalina or earlier for smooth operation.
All Apogee Quarte USB drivers can be downloaded here under Legacy Product Installers:
Current software and firmware versions are shown here
AVID PRO TOOLS QUARTET
For the AVID Pro Tools Quartet, this is a discontinued AVID product
The drivers we provide on our site will not work for AVID Quartet models
This unit is only compatible with Intel Macs up to Mac OS 10.14.6. Drivers are provided by AVID on their website here.