a live looping concert with open source software only


So this is a comment on the first concert I did together with a friend, using live looping software (sooperlooper) and an effect program (creox) to connect a microphone. Well, to a cheap stereo audio interface (m-audio transit) which got its input from a little DJ mixer (as a preamp with band filters) which had the mic plugged in. The output of everything (the live voice and the loops) left through one stereo output into the master mixer. My friend entered into it with an electric bass guitar (with echo). A forty five minute “gig” without any major problems. I’ll tell you how I connected it, the problems I ran into and some tips and tricks.

The beginning: Plug in the cables as said above. Start JACK. This is the configuration I used with an m-audio transit audio card:

This works quite well, some XRUNs happend (maybe 10 or 20 in the whole concert) but since the concert was very saturated and distorted one hardly notices anything. Well, on the recording I didn’t.

Then I started creox, put it into run mode and started sooperlooper. Make sure that the input is not piped twice to the output. Which means that audio input goes once into creox and from there only to sooperlooper. Sooperloopers’ common out goes to system out. One could also make sooperlooper to only output the loops and not the input and let creox feed it into system out apart from to sooperlooper. Anyway, just be sure. It avoids volume confusion… Well this was my jack audio connection:

connect audio ports

connecting audio ports

When everything is connected fine one should see level changes in the sooperlooper window when talking into the microphone and hear something as well. Next I run vkeybd to have MIDI control. To connect it with sooperlooper one has to go into the ALSA tab! Not MIDI tab. I don’t know why, but this is how it goes:
connecting midi ports

connecting midi ports

There is a nice tool in the jackcontrol center: the patchbay. Connections can be saved and, after being loaded, one activates the preset. For me it didn’t work 100%. First: creox connects by default to system out and the patchbay doesn’t unmark that connection. This lead to above mentioned volume confusion. The other audio connections worked fine. But second: somehow the MIDI channeling does not work at all. The pacthbay recognises them but does not activate them. I did it by hand. Still, the patchbay saves major work in channelling the ports before a playing.

So now everything is working. I opened 5 stereo channels in sooperlooper and had the keyboard prepared for vkeybd. I used "1 2 3 4 5" for the first channel, "Q W E R T" for the second and so on (using only "8 9 0" for the last one). With the focus on vkeybd the show can start:

live screenshot

live looping screenshot

Unfortunately I don’t have the opportunity to host the record at the moment but when it it is time I will post the link.
There was only one problem which kind of annoyed quite a lot. Sometimes the MIDI conversation between the virtual keyboard and the looper gets confused. We did a test before the concert so I had al loops full of samples when we started. When I started to record the first bit, suddenly everything got turned on. What a mess! I restarted and rewired vkeybd and then it was fine. I don’t know what happened before the concert. I had this before and it was only after having a break. So I have to investigate more to see what it is about, but all together the show was a nice bit of fun and I think most of the people listening to us enjoyed it as well.
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8 Responses to “a live looping concert with open source software only”


  1. 1 Chris October 15, 2008 at 10:15 pm

    Thanks for sharing your experiences with sooperlooper! They are a real help. I’m working on a SL setup to replace my Boss RC-20 (the limitations of which I’m fed up with!) In fact, here’s my planned setup:

    If you have any tips or feedback, I’d love to hear them. I have a bunch of questions about what SL can do, and am anxiously waiting for my newly-ordered equipment to arrive so I can start experimenting. One quick question: can SL output a click track to headphones, but not the main out? It would help my drummer to have a click to play along with, but we don’t want the audience to hear it.

    Again, thanks!

    -Chris

  2. 2 linuxaudiolive October 16, 2008 at 7:58 am

    Chris: if you have more than one output on your audio card, there should be no problem to output a click track to the headphones since you can connect the tracks individually in the JACK connections instead of everything via the “common out”.

  3. 3 Chris October 17, 2008 at 8:20 pm

    Great. That’s what I was hoping for, and what conceptually makes sense. A question, though: I had a lot of problems getting jack to work well a couple weeks ago. I got it to work pretty seamlessly in Playback mode, but Capture or Duplex would crap out consistently. Do you think this was because of my soundcard? I’ve ordered a firewire audio interface (Focusrite Saffire LE), but it hasn’t arrived yet. I was hoping to have jack all set up in advance, but your post seems to imply that all the hardware needs to be set up first, before jack is started (“The beginning: Plug in the cables as said above. Start JACK.”)

    Again, thanks.

  4. 4 linuxaudiolive November 11, 2008 at 11:31 am

    Well, I’m not sure. My soundcard is a cheap USB card. It’s not bad. Maybe you have to change buffer sizes or things like that so that you will have higher latency. However, I think jack cannot be started without the sound card present.

  5. 5 carsonfb April 17, 2009 at 12:24 am

    Thanks for posting your experiences using Creox and Sooperlooper. I am considering using Creox in place of an amp and microphone for recording as my home is acoustically challenged. It sounds like this should go smoothly based on your review.

    I do have one question though. Do you use the real-time kernel, or the normal one? I haven’t had good experiences using the real-time kernel, but I am told that it is supposed to be better for recording and processing music.

    • 6 linuxaudiolive April 17, 2009 at 8:22 am

      I do use the real-time kernel and I suppose it’s the way to do it. The jack audio server probably won’t be to happy with the normal kernel.

      I don’t know what kind of experiences you had but on one of my machines I still decide on boot time which kernel to use, because some features are not supported by the real-time kernel (on the eeepc).

  6. 7 raboof July 19, 2009 at 11:23 am

    About the MIDI and ALSA tabs: the MIDI tab is for the relatively new ‘JACK MIDI’, the ALSA tab is for the well-known ‘ALSA MIDI’.

    Nice article, I’d like to hear the recording – I can host it for you if you want. Let me know.

    I took the liberty of adding you to http://planet.linuxmusicians.com/

    • 8 linuxaudiolive July 25, 2009 at 3:00 pm

      Thank you for adding the link to the linuxmusician planet. I just read about that site a week ago and I’ll check it out more.

      We hosted the concert in myspace. High compression and a highly distorted and saturated recording make it a bit of a headache. But well, listen myspace.com/nkokemikal.

      JACK MIDI/ALSA MIDI, hmm… I never have anything showing up on the JACK MIDI tab, so suppose it is not installed or something like that. By the way, did you ever get JACKRACK connected to a MIDI source?


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