Logic Pro 9 Crazy audio behavior w/ newly installed Logic 9

David Zapata

New Member
I am in the throes of configuring my new iMac (2.66 GHz Intel Core i5 etc.) with an out of the box copy of Logic 9 and am having problems with the audio output. I have an Presonus Audiobox USB as my AI device hooked up to both the iMac and my Mackie 1202 VLZ mixer which in turn connects to my speakers. Here's the deal; when I start up the computer, I get crazy distorted white noise when I play any audio source from the computer; iTunes, internet or a Logic session. This problem goes away once I manually remove and re-plug the Audiobox USB from its location on my computer - to the same location. I've set the sound in system preferences to the Audiobox, and in Logic I do the same, but it's not until I remove and re-plug that I get around the problem. Is there some sort of USB addressing thing going on or what? Your thoughts would be appreciated.



Staff member
Welcome to the LUG, David.

Have you checked that the Audiobox is showing in Audio Midi Setup as being correctly installed in your system? Are you using the latest drivers?

It might be worthwhile contacting presonus about this.

kind regards

Upvote 0
I agree, I use a USB Line 6 interface and have never once experienced any audio issues of this type. My suggestion is that the Presonus may well be the issue. Can you take it back and get another, or do you have another Mac you can try it on to see if the behavior changes?

George Leger III
Upvote 0


So far I haven't had any problems with my Audiobox USB, but I wish I had looked into the Focusrite Saffire. The lack of line level inputs on the Audiobox, and the outputs for both a mixer and monitors on the Saffire are making me want to replace mine, too.
Upvote 0