Call Us: 01202 597180
We're open: Monday - Saturday 10am - 6pm
Sundays and Bank Holidays 10am - 4pm.


Posted on July 30, 2012 by Joe Stachowiak There have been 18 comment(s)

Mac OS X Lion LogoAn aggregate audio device allows you to combine multiple interfaces and access them as one unit. So, for example, if you have one interface with 2 inputs and 2 outputs and another with 4 inputs and 2 outputs, you can set them up as an aggregate device so that your computer will recognise them as one interface with 6 inputs and 4 outputs!

Please note that this information details how to set up an aggregate device on a Mac with the 10.7.4 operating system and although the principles are likely to remain the same with future OS X updates, some of the screenshots may not exactly match what you see on more up-to-date operating systems.

To set up an aggregate device on the Mac OS X Lion operating system:

1. Ensure that all devices that you want to combine into an Aggregate Device are connected to your computer.

2. Within your Mac Finder, navigate to Applications → Utilities.

3. Find the Application called ‘Audio MIDI Setup’ and double-click to open it.

Audio MIDI Setup

Audio MIDI Setup

4. Something resembling the following screen should open, although the options in the left-hand column will reflect the audio devices that you have available on or connected to your system.

Audio/MIDI Setup Window

Audio/MIDI Setup Window

5. Click on the '+' symbol in the bottom left-hand corner of the window...

Audio/MIDI Settings 'Plus' Button

Audio/MIDI Settings 'Plus' Button

6. ... then click 'Create Aggregate Device'.

Create Aggregate Device

Create Aggregate Device

7. You should notice that a new audio device called 'Aggregate Device' has been created in your list. When selected, it will display a list of all other available input and output devices in the larger pane to the right.

Aggregate Device

Aggregate Device

8. If you want to rename the aggregate device, ensure that it is selected in the left-hand column and then click the 'Aggregate Device' text....

Rename Aggregate Device

Rename Aggregate Device

9. ... and then type in a name for your aggregate device. This is useful because you can create multiple aggregate devices on a system and so it allows you to give each one a descriptive name.

Once you have typed in the new name, click anywhere else on the screen or press the 'Return' key on your keyboard.

Renamed Aggregate Device

Renamed Aggregate Device

10. To add devices to an aggregate device, click the 'Use' checkbox next to the corresponding device in the right-hand pane.

Adding Devices

Adding Devices

In the above example, the computer's built-in input and output have been added to the aggregate device, along with the 2 channel Soundflower device.

11. Once you have added all your chosen devices to the aggregate device, you will need to specify which one will act as your master device. You do this using the drop-down 'Clock Source' menu and clicking on your chosen device.

Clock Source Device

Clock Source Device

12. If your devices support word clock, connect them together in this way to provide syncronization.

If any of your devices do not support word clock, click the 'Drift' checkbox next to the corresponding device(s), except for the clock source device - this option enables resampling to combat drift for devices that aren't connected up using word clock.

'Drift' Checkbox

'Drift' Checkbox

13. Ensure that all devices within the aggregate audio device are set to the same sample rate (i.e. the sample rate of the master/clock source device).

If all devices are not set to the same sample rate, the aggregate audio device will not work correctly. You can usually set the sample rates of your audio devices in the Audio/MIDI set-up window (by selecting the device in the left-hand column and changing the sample rate in the right-hand pane), but different audio devices may require you to set it elsewhere. If you find that you cannot adjust the sample rate for a particular device in the Audio/MIDI Setup window, please refer to the user guide for that device.

Note that you can also change the sample rate of the master device using the 'Sample Rate drop-down menu.

Sample Rate Menu - (all other devices should match this)

Sample Rate Menu - (all other devices should match this)

14. Close the Audio/MIDI Setup window - you have now created your aggregate device!

15. If you want to use your aggregate device within some software, open up the software and your aggregate device should appear within the list of available audio devices. Select it and configure it within your software as you would any other audio device.

Selecting the Aggregate Device in Logic

Selecting the Aggregate Device in Logic

For a more detailed description of how to select an aggregate audio device in Logic Pro, click here.

If you have any more questions then please feel free to leave comments below.

We hope that helped!

This post was posted in Blog entries, Computer Music, How To Guides, Recording and was tagged with aggregate audio device, logic, logic pro, mac, os x lion


  • Steven says:

    Thanks for the run through however im having an issue using 3 wireless speakers set as an aggregate device and setting this as the sound output ?

    It simply wont work with more than one pair of the bluetooth speakers ? Any ideas ?

    Posted on February 7, 2013 at 5:22 pm

  • Hi Steven. I'm afraid that this isn't something I've done before so I've not got a definite answer for you. I'm guessing that the set-up instructions that came with them isn't too helpful? One thing that I would advise trying is going to Applications -> Utilities -> Audio MIDI Setup -> Click on your desired output aggregate interface -> Configure Speakers... -> Multichannel -> Select an output configuration that isn't stereo. I'm guessing that at the moment you have your device set-up as stereo so it is only routing sound to 2 of them. Hopefully that solves it but that's just a guess as I've never tried to configure bluetooth speakers as an aggregate device bevice. If you find a fix for it then feel free to drop back and let us know in case future readers have the same problems. Good luck and sorry I couldn't offer more help on this one.

    Posted on February 8, 2013 at 10:07 am

  • Debz says:

    Hi Steven, I have a problem when connecting usb mixer. My mac settings change to input an output usb mixer. I hear the music from the mac in my mixer headphones and the mic (plugged into mixer) however when I try to record I can only get the microphone to record. Any ideas how I would set up aggregate device for this. I have tried several options and I still cannot get the music and mic to stream together, its either one or the other that is recorded? Thanks in advance for any advice you may have.

    Posted on March 22, 2013 at 6:55 am

  • Hi Debz, what mixer do you have and what software are you trying to record to? Where is the music you are trying to record coming from? Do you have something like an mp3 player plugged into your mixer or are you playing the music from your computer and trying to record it back into your computer?

    Posted on March 22, 2013 at 9:57 am

  • Mark says:


    Thanks so much for this post. It's been extremely helpful.

    I followed your directions to create an aggregate device to use in Garageband. It worked famously for a while, but now the monitoring is not functioning properly.

    Previously, I would create an aggregate device consisting of four logitech headsets and then select that aggregate device as both output and input in Garageband. Each person had their own track and I was able to turn on the monitor for each headset. Each person could hear everyone in the aggregate through the monitor, which was helpful for monitoring ambient noise.

    For some reason, I am no longer able to use the monitor for all of the headsets. The only headset that receives sound when monitoring is the first device in the aggregate.

    This is driving me crazy because I don't think I changed anything. Any tips?

    Posted on April 6, 2013 at 3:50 pm

  • Hi Mark and I'm glad that the tutorial helped... at least at first! Your problem does sound very peculiar, especially as it was working fine and now seems to be playing up. Are your headsets all connected to your computer via USB?

    How do you have your tracks set up in Garageband? Have you set up each track to output to the appropriate output of the aggregate device? E.g. is track 1's output set to 'output 1', track 2's output set to 'output 2' etc? If you view your aggregate device in the Audio MIDI Setup window does it show all of your headsets? Have you tried re-creating the aggregate device at all?

    Let me know how you get on :)

    Posted on April 8, 2013 at 10:20 am

  • Jacob says:

    IM currently use my M-audio Interface, with logic but whenever i want to use internal audio for itunes or spotify i usually have to unplug the output from my interface and then back into my computer - as i only have one set of spekers and the amp only has one input..... Ive tried to use the aggregate device so that all my audio exits through my interface, is this possible? if so would you be as kind to help me!? thanks for the post tho interesting to read and hopefully helpful for my case :-)

    Posted on May 2, 2013 at 3:28 pm

  • Jacob says:

    Ah dont worry i just did it, would help if i had clicked righ mouse and 'use this device for output' ;-)

    Posted on May 2, 2013 at 3:34 pm

  • Excellent, glad that you managed to sort it :)

    Posted on May 2, 2013 at 5:10 pm

  • Jacob says:

    Hiya, thanks for this its making life a lot easier, as im often switching between inputs n outputs.
    One thing im try to figure out however, is ive now set all my outputs to run through my interface, but if im using my computer sound ie playing from itunes or music libary, how can i pan audio? obviously i can do it with logic, but i cant do it within the computer now becuase the internal output if off........ WOuld appreciate your help thanks.

    Posted on May 3, 2013 at 9:51 am

  • Hi Jacob. I think you are going to need to do this in your routing software if your interface comes with one. I will attempt to do it on my own system tonight. What interface are you using?

    Posted on May 7, 2013 at 9:39 am

  • Hi Jacob, Thanks for the post. However this does not seem to work for me. My setup is as follows:
    Mic -to- Behringer Xenyx 802 (mixer) -to- Behringer UCA222 (USB Audio CODEC) -to- USB (Macbook Pro/Lion)
    Built-in output

    Aggregate Device:
    Built-in Output
    USB Audio CODEC (0 in, 2 Out)
    USB Audio CODEC (2in, 2 Out)

    Recording Application:
    Audacity (2.0.4) Output = Built-inOutput Input = Aggregate Device

    Expected recorded streams:
    Mic (attached to mixer/usb audio device)
    Chrome (Youtube video) or
    Skype Call

    Recorded streams:
    Mic (only)

    Any assistance would be greatly appreciated. Thanks in advance

    Posted on November 3, 2013 at 5:20 pm

  • I have 2 yeti microphones that I want to aggregate for teleconferencing. The sound preferences and the MIDI application only ever sees that there's one mic connected to the computer, but each mic and cable work fine. Any ideas?

    Posted on February 10, 2014 at 2:55 am

  • Hi David,

    I'm afraid that I'm not too sure what the issue is if I'm being honest. I'm guessing that it has something to do with the fact that you're using two of the same devices (which is something that I've not tried before), but I always thought that this should work fine and I'm afraid that I don't have any explanation as to why it isn't working. I've done a search online but I can't find anyone else who has posted about this issue. Your best bet is probably to post on an official Mac forum. Sorry that I couldn't be more help on this one.

    Posted on February 10, 2014 at 11:11 am

  • Thanks for responding Joe. I did some searching and it appears that the problem is that both devices have the same USB name, so the Mac only recognized the one more recently plugged in.

    Posted on February 10, 2014 at 8:12 pm

  • Ah, that makes sense. Thanks for reporting back, that's good to know for the future. Did you find a workaround?

    Posted on February 11, 2014 at 9:46 am

  • Excellent Article!

    I'm having issues in this particular area, and what I see everywhere is creation of aggregate devices on the smallest scale.

    Could you perhaps shed some light on using 2 larger independent interfaces? In my situation I am trying to use a Projectmix i/o, which is firewire and has 8 in's and 4 outs with a US1800 USB interface, which has 8 ins and 4 outs.
    It would be neat if I could use them together to have 16 ins and 8 outs, and certainly take me up a notch or two in what I can get done.

    There is literally nothing about this anywhere Ive looked so far, and I'm on the third day of searching and several pages in on my refined google search. So Any help would be most appreciated!



    Posted on March 15, 2014 at 4:23 pm

  • Hi Eric, I've not tried mixing a USB interface with a Firewire one when creating an aggregate device, but as far as I'm aware, this should work and the procedure should be exactly the same. Likewise, aggregating two devices with more inputs and outputs follows the same steps. Have you tried it? Are you having problems? If so, where are you experiencing these problems? Thanks.

    Posted on March 18, 2014 at 10:52 am