Quartet: General

Are all MIDI devices compatible with Quartet’s USB MIDI port?

No. Only Core-MIDI USB devices will work with the Quartet’s MIDI port.

Most new USB music keyboards and drum pads are Core-MIDI devices, but this will vary from different manufacturers. Please refer to that device’s Owner’s Manual or specification to confirm class compliance with Core-MIDI.

In general, MIDI devices that can be plugged into a Mac’s USB port and used without needing to install additional software or drivers are likely Core-MIDI compliant.

Does Quartet work with Apple FaceTime?

Yes, if a microphone is connected to a Quartet Input and Speakers or Headphones are connected to Outputs FaceTime works correctly. Quartet must be selected to be the  Input and Output source for the Mac. This is done by opening the Apple Audio MIDI Setup Utility in the Utilities folder, Selecting the Quartet in the left column, then Right or Control Click on it and select “Use this device for Sound Input and Output “.  Alternatively this can be setup in System Preferences Sound page by selecting Quartet for Input and Output.

Why doesn’t Quartet use Thunderbolt?

Thunderbolt is clearly the future for connecting the highest bandwidth peripherals to your Mac. For the peripherals that require such bandwidth, the higher cost of Thunderbolt components and accessories (such as cables) is worth it. High resolution video, for example, requires significant bandwidth so its associated peripherals would undoubtedly benefit from Thunderbolt connectivity.

Quartet’s bandwidth requirements are comparatively small next to high-resolution video peripherals, and are easily fulfilled by USB 2.0. The latency with USB 2.0 Audio is excellent – just 3.6ms (roundtrip) when recording in Logic at 96KHz/32-buffer. Plus the inclusion of Thunderbolt would increase Quartet’s cost significantly without adding a great deal of benefit.

In the end, USB 2.0 is simply the most appropriate connection for Quartet, providing more than enough bandwidth and low latency at a reasonable cost.

Why doesn’t Quartet use USB 3.0?

Quite simply, USB 3.0 doesn’t provide any benefit for digital audio over USB – USB 2’s bandwidth is more than adequate, and USB 3 doesn’t get the data to its destination any faster.

Imagine an airline route between two cities – planes take off at regular intervals and take a certain amount of time to arrive at their destination. If the airline were to double the size of their planes, the number of passengers that can fly between the two cities – the bandwidth – doubles. But each passenger doesn’t get to their destination any faster. Moreover, if the smaller planes can easily accommodate the number of people who desire to fly that route, there’s no reason to run the larger planes.

Likewise, the bit-rate of a digital audio signal, even with several channels at 192kHz sampling rate, is easily transferred over USB 2. Digital audio doesn’t arrive at its destination any faster over USB 3, thus latency doesn’t improve.

Using Quartet with Duet 2 – Aggregate Device Setup


Before you get started, make sure that you have updated the firmware on both the Duet2 and the Quartet to their most recent versions. After the firmware has been updated, run the most recent Duet2 software installer first and then run the most recent Quartet software installer.

1) After you have run both software installers, open up “Audio MIDI Setup”, found in Applications > Utilities.

2) Make sure both Duet2 and Quartet are set to the same sample-rate by selecting each device and choosing the correct sample-rate from the drop-down menu.

3) Create an Aggregate Device in Audio MIDI Setup by clicking on the “+” icon at the bottom left side of the device column and selecting “Create Aggregate Device”.

4) In the right side of Audio MIDI Setup, select the checkbox to use Quartet first and then select Duet USB. The Clock Source drop-down menu should say “Quartet”. 

5) With “Aggregate Device” still selected, go back to the bottom of the device column and click on the “gear” icon. Choose “Use This Device For Sound Input” and “Use This Device For Sound Output” to set your Aggregate Device as the default input & output. The Aggregate Device should now show the speaker and mic icons next to it.


Using Logic

1) Launch Logic and go to the Audio Preferences (Logic Pro > Preferences > Audio). Click on the drop-down menu for the Output Device and select “Aggregate Device”. It should automatically select Aggregate Device for your Input Device as well. Click the “Apply Changes” button at the bottom of the window.

2) To set up the I/O labels in Logic for your Aggregate Device, go to the Options menu, select “Audio” and then “I/O Labels”. The I/O Labels window will appear. Click anywhere in the window and then press Command-A to select all. Now click on one of the circles in the “Provided by Driver” column. This will select all of the i/o labels for your Aggregate Device. Close the I/O Labels window.

3) Now you’re ready to record with your Aggregate Device! Create a track and assign your input and output. The Quartet’s input and output will start from the top of the list since it was the first device you chose when creating an Aggregate Device, followed by Duet2’s input and output.

Hotplugging devices or sleep/wake while Logic is open isn’t recommended while using an Aggregate Device. If you hotplug or sleep/wake, you may have to quit and relaunch Logic.


Using ProTools

1) Launch ProTools and before creating or opening a session, select “Playback Engine” by clicking on the Setup menu. Select “Aggregate Device” in the top drop-down menu for the Playback Engine and then click “OK”. ProTools may have to quit and relaunch after this.

2) After you’ve relaunched ProTools, go to the “I/O Setup” by clicking on the Setup menu and selecting “I/O”. After the I/O Setup window opens, click “Default” in both the input and output tabs.

3) You can customize the i/o labels by double-clicking on an entry and entering a label of your choice. Keep in mind Quartet’s inputs and outputs will start at the top of the list since it was the first device you chose when creating an Aggregate Device, followed by Duet2’s input and output.

Hotplugging devices or sleep/wake while ProTools is open isn’t recommended while using an Aggregate Device. If you hotplug or sleep/wake, you may have to quit and relaunch ProTools.



If you ever run into “choppy” audio or clicks and pops while using an Aggregate Device, here is a list of troubleshooting tips:

– Make sure both devices are set to the same sample-rate in Audio MIDI Setup

– Quit and relaunch Logic or ProTools.

– Reload the driver in Logic by going to the Audio Preferences, toggling the I/O Buffer Size back & forth and then clicking “Apply Changes”.

– Try raising the I/O Buffer Size in Logic’s Audio Preferences or ProTools’ Playback Engine.

– Open Audio MIDI Setup, delete Aggregate Device and create a new Aggregate Device using the steps above.

Can Quartet lock to an ADAT/SMUX optical clock source?


Though the Quartet can receive signal from an ADAT/SMUX source, it can only do so if the ADAT/SMUX device is clocked to the Quartet via the BNC connection. This is because the Quartet must be the master clock.

For information on clocking external device to Quartet, consult the Quartet’s User’s Guide.

Quartet User’s Guide

What is the maximum current capacity of the 48V phantom power? Will it handle any microphone?

Any Apogee product that includes microphone inputs with 48v phantom power is designed to handle loads up to a complete short, or 14.1 mA. This will properly power any microphone.