I have an original MBox that doesn't play well with PT9 HD. Poor thing just sits on the shelf all day, waiting to be put to good use. Can I use it as an aggregate device with the new version of Pro Tools? If so, how? Do I connect thru USB, SPDIF, Line Out, or...?

5 Answers 5


Hi guys,

I'll clear this up for you. Legacy Mbox 1 is not supported under PT 8.0.1 onwards. There is a Russian driver knocking around, but it simply won't work on any PT system post 8.0.1.

The Aggregate I/O is a system that will collate all of your connected Audio Hardware and represent the inputs and outputs together in I/O Settings. I theory, you could use 2 Audio INterfaces in tandem with each other under the Aggregate I/O. I understand it's quite unstable though and I wouldn't recommend for critical audio capture.

You can configure all of your Audio Interfaces to be seen under the Aggregate I/O in AMS in Mac.

The "Can't set Sample Rate" is an easy fix - PT installer has installed multiple instances of the Aggregate I/O and PT is trying to open the session with a different instance of the Aggregate I/O that is already running and you'll always get this message. Simple fix it load pro tools, but don't open a session. Go into Playback Engine in the settings menu and change the Current Engine Value to either Built in Output for your internal soundcard or the name of your connected Audio Interface.

Good luck

Dave Phillips Avid Certified www.davephillipsmusic.co.uk


Take this with a large gain of salt as I don't have PT9 yet, so I haven't personally had my hands on it to see this first hand:

As I understand PT9's use of the term "aggregate devices", it basically means non-Avid audio hardware/software interfaces. So, for example, you can set up a MOTU Traveller mk3, Cycling 74's Soundflower or even your Mac's Line In as an input device under Setup > Hardware Setup and have it pop up on your Setup > I/O page. However, the devices still connect in the same USB2/Firewire/System Extension manner that they normally would be used with any other DAW.

This might explain it a little better (it has visual aids): Aggregate Devices Function Demo

But, because Avid's Pro Tools 9.0 Approved Audio Interfaces and Peripherals page has this little disclaimer:

Please Note: The original Mbox (1st generation) and Digi 001 are not compatible with Pro Tools 9, and are not eligible for the Pro Tools LE to Pro Tools 9 Crossgrade. One of the above Avid audio interfaces is required for the special Pro Tools 9 Crossgrade from LE pricing.

I'd imagine that you're simply outta luck on using that original MBox with PT9. I'd go a step further to blame it on the original MBox's older USB input vs. USB2 that I would expect to see in the specs of the devices that are approved. But now I'm just hypothesizing, and making sweeping assumptions. So, let's just forget that last part.

  • As @Steve wrote, Avid interfaces cannot be Aggregated. Tried with a mbox2 before selling it and with my Digi002. (But using Soundflower in ProTools open up a brave new world! :-) ) Commented Mar 29, 2011 at 0:00
  • So let me get this straight @Davide, you can't have multiple Avid interfaces? ie.You can't aggregate an Mbox2 against a PT9 system running with a 002 as the main interface? Commented Mar 29, 2011 at 3:21
  • @Steve No, it's not possible. Commented Apr 6, 2011 at 13:43

Not 100% sure, but I think the MBox should work under the aggregate I/O. To use it, you need to enable it in Audio MIDI Setup, which you can find in Applications/Utilities. Select the Pro Tools Aggregate I/O and check off your MBox under the Use column and you should be good to go.


i dunno. getting some of these myself. think i'm not alone......

alt text http://i51.tinypic.com/34es5k7.png

I also noticed that PT9 uninstalls the Mbox 2 Coreaudio driver/extension and replaces it with a "Digi Coreaudio device" one. I imagine if you manage to get your original Mbox 1 running in CoreAudio mode, then PT9 will be happy using it. Yet I suspect they wouldn't want to do anything CoreAudio on that box.

I suspect the first Mbox was made by Focusrite so that might help to a certain extent when tracking a driver (esp via the osx86 community). I wouldn't bet on it.

  • Sorry, how does your answer relate to mbox and aggregate devices? Commented Mar 28, 2011 at 22:20
  • this is the first message I got when I set PT to use an aggregate device - in that case the Echo Audiofire 4 + Built-in audio (which totally does support 48kHz). The device labelled "Pro Tools Aggregate I/O" is automatically created by PT9 on first launch. It is a standard OS X aggregate device. You can delete it from Audio MIDI setup. PT9 will recreate it
    – georgi
    Commented Mar 28, 2011 at 22:39
  • ok, understood. Thanks for the clarification. Commented Mar 30, 2011 at 9:13

I found a smallish article on this the other day when looking for SFX library software.

Iced Audio's AudioFinder website came up with this:


Hope that helps,


  • @Fred, thanks for posting. Seems to be basically the same information that I've come across on the Avid site as well as related sites. Would love to hear from someone who actually has this setup working. Commented Mar 30, 2011 at 9:11

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