View Full Version : [ubuntu] What do I need JACK for?

March 8th, 2011, 07:45 PM
I'm an ubuntu noob and I installed a copy of 10.10 today.

The first thing I wanted to do was get my Behringer UCA202 USB sound card to work because the sound was initially coming out from the laptop speakers and not through my bookshelf speakers via the USB sound card. It didn't occur to me outright to fiddle with the sound preferences, but that's what eventually solved my problem. I just picked the correct device in the sound preferences and everything was fine.

My question is actually related to what I did before I solved the problem. Before actually trying the obvious solution, I found myself researching about audio for ubuntu, which led me to JACK, which I wasn't able to configure properly. My question is: What exactly do I need JACK for? If I'm able to use my USB speakers and play audio and video fine with it, what's the purpose of setting up JACK?

March 8th, 2011, 07:56 PM
You need JACK for fixing a flat tire on your car...:lolflag: JUST KIDDING

What is JACK? (http://jackaudio.org/node/11)

Have you ever wanted to take the audio output of one piece of software and send it to another? How about taking the output of that same program and send it to two others, then record the result in the first program? Or maybe you're a programmer who writes real-time audio and music applications and who is looking for a cross-platform API that enables not only device sharing but also inter-application audio routing, and is incredibly easy to learn and use (http://jackaudio.org/files/docs/html/index.html)? If so, JACK may be what you've been looking for.
JACK is system for handling real-time, low latency audio (and MIDI). It runs on GNU/Linux, Solaris, FreeBSD, OS X and Windows (and can be ported to other POSIX-conformant platforms). It can connect a number of different applications to an audio device, as well as allowing them to share audio between themselves. Its clients can run in their own processes (ie. as normal applications), or can they can run within the JACK server (ie. as a "plugin"). JACK also has support for distributing audio processing across a network, both fast & reliable LANs as well as slower, less reliable WANs.

JACK was designed from the ground up for professional audio work, and its design focuses on two key areas: synchronous execution of all clients, and low latency operation. More background information (http://jackaudio.org/documentation) is available.
Understanding JACK in different ways

Jack Homepage (http://jackaudio.org/)

Essentially if you are a DJ or someone who works with audio, that is when you will need JACK. If you don't do much audio work I wouldn't worry about it to much. :)


March 9th, 2011, 03:17 PM
Thanks for that bit of info :) Actually, I do work with audio since I record music.

On Windows 7, I used to do it on Reaper.

Hopefully I could find an efficient DAW for Ubuntu :) [and be able to setup JACK properly as well]

March 9th, 2011, 03:25 PM
Reaper is actually one of the few DAWs that work well under Wine:

But you will still need jack of course. If you want to try something made for Linux, try out Qtractor.

March 9th, 2011, 03:43 PM
Silly me. I forgot...

Welcome to the Forums! :D

I can't believe I didn't notice that was your first post...

Glad I could help. As to how you use/manipulate JACK I have no idea, but I know some people on the forums can help. :)