24" Apple Cinema Display audio problem

[Jwhitehead333]

Hey guys,
I just purchased a 24" ACD, after connecting the 3 cables (power, display out and USB) I also connect my external speakers through my mac book pros headphone output. When i play iTunes or a video on youtube, the sound comes out of my external speakers, which is what i want. When I play something in Pro Tool 9 (without changing anything), it comes out of the ACDs speakers, which aren't as good. Obviously i want to fix this.
I searched this forum, and google, but could not find out what the problem is.
Thanks for any help.

[Jwhitehead333]

Anyone have any ideas? Im using a 2011 Macbook Pro, running lion 10.7.1, could it be a bug with lion, or a setting on Pro Tools 9.0.5?
cheers

[Darryl Ramm]

The Pro Tools 9 Playback engine is set to...?

In Audio Midi Setup settings what device is set to play the system sound output?

If you are using an aggregate I/O device for the playback engine in Pro Tools 9. What us the audio output of that device set to?

Clicking around and finding these answers will help you see how to solve your problem. If you really don't need aggregate I/O then just set the playback engine to use whatever audio output device you want to directly.

Darryl

[Jwhitehead333]

Hey Darryl,
Playback engine was set to 'display audio', i changed it to 'built in output'. This fixed the problem.
Thanks for your help, i guess it was pretty obvious, I had looked around in Pro Tools Preferences, but i found nothing.
I'm also new to Pro Tools and ACDs.
Again, thanks for the help.