Presonus Firebox

I got me one of these - Presonus Firebox Firewire 24/96 audio interface. It's awesome, and comes with two microphone preamps.

Ubuntu 9.04 Setup

This device works well in Linux through the freeBoB firewire driver project, but only through the JACK audio server, which for best results requires a realtime kernel.

Install Prerequisites

So to get this device working nicely, we need to install a real-time kernel, the jack audio server, and Ardour to do useful editing. The easiest way to do this is to simply install Ubuntu Studio:

apt-get install ubuntustudio-audio

Or, individually:

sudo apt-get install linux-rt linux-headers-rt qjackctl ardour

Configure Realtime Scheduling

Add the following to the bottom of /etc/security/limits.conf to set up real-time audio:

@audio - rtprio 99
@audio - memlock unlimited
@audio - nice -10

NOTE

ensure there's an audio group and that you're in it, or else substitute @audio here with your username.

Configure Device Detection

Ubuntu 9.04 finds the device okay, but sets it up so only root can do anything with it. To fix this, get udev to find your Firewire gadgets and set up the permissions properly. If not already there, create a /etc/udev/40-linux1394.rules file and add the following:

KERNEL="raw1394", NAME="%k"
KERNEL="dv1394*", NAME="dv1394/%n"
KERNEL="video1394*", NAME="video1394/%n"
KERNEL="raw1394", GROUP="rawfw"

Create the rawfw group and add yourself to it. Only these users will have access to the raw Firewire interface:

groupadd rawfw
sudo adduser username rawfw

Finally, in the Jack GUI setup, use the freebob driver and ensure the Realtime option is ticked.

References

• https://help.ubuntu.com/community/UbuntuStudioPreparation
• http://jackaudio.org/faq
• Do we really need memlock? http://www.64studio.com/node/571
• http://freebob.sourceforge.net/index.php/UdevConfiguration