Not audio on linux

What happens if you select default or sysdefault as output device? Do you have the option of selecting Jack instead of ALSA?

Jack is yet another audio server, that's especially suited for audio, because of low latency and advanced routing capabilities. I believe that Jack is a dependency of Bitwig, so if you have Bitwig running on a Linux machine, it should be installed. There are graphical user interfaces for setup, like QjackCtl and Cadence. You should be able to find QjackCtl in Synaptics Package Manager or even the Software Center. Here is something to read regarding settings and use: UbuntuStudio

There are often issues when trying to run Jack and Pulse together. If you do run into such issues, you could try Option 4 mentioned here, before you try more drastic measure, like killing Jack at start up and manually loading it when you need really it.

I would however suggest to go ahead and install either the Ubuntu Studio or KXStudio packages. Especially KXStudio comes set up pretty well for audio and includes a ton of audio applications and even some LInux VST plugins, which you can use right away in Bitwig.

What other output devices can you choose from? Maybe try a few different ones, if there are multiple options. Also check your output channel in the "Studio I/O" section of the browser (very right button on the bottom).

For what it's worth, both Input Device and Output Device on my machine are set to "system" and Audio System is "Jack Audio Connection Kit". That requires Jack to be installed and set up (that's where I choose my audio interface" and running though. Installing Jack makes a lot of sense, if you want to do a fair bit of audio tinkering on Linux. It allows you things like connecting different applications and if the application supports Jack transport, you can run them synchronized. Jack transport is not supported in Bitwig yet, but according to Dom it's on the list. Also, Pulse is prone to cause problems with Linux audio applications. My computers runs on KXStudio, which does not have Pulse installed at all, because of that. You can just disable Pulse on startup and only call it when you really need it. Killing Pulse is another option, but I found it to be quite persistent if not killed right on startup. Hope that some of that helps.

From my experience i strongly recommend using jack over pulseaudio.

The short and easy solution to this ist maybe just the installation of the "ubuntustudio-desktop" package. A lot of additional stuff will be installed, but i remember this to be the least annoying and time-consuming option on Ubuntu :)

If you want to set it up as a single package, check out this page (in german): http://wiki.ubuntuusers.de/jack

Basically the most important step is: sudo apt-get install jackd qjackctl

After that, you should work out a configuration for jack, either on the command line, or in qjackctl. After that, i recommend installing the pulseaudio Sinks and Sources for jack to be able to use every sound application on linux at the same time.

If you need more hints, i can provide you with more detailed information about my setup :)

mine is set to pulse