Minus Mix

I am running ubuntu studio 14.04. I have an M-Audio Fast Track Ultra (6ch +spdif stereo).

I have a podcast and would like to have the ability to interview on skype. Is there somewhere with a tutorial on how to do a minus mix in Ardour? I know I can do it in a commercial daw I use for other projects, but for the podcast we only use Linux.

Thanks in advance!

This isn’t hard to do assuming you can get skype feeding into JACK. That’s the hard part. There are lots of documents online about how to get non-JACK software to interface with JACK, but a lot of them are very long (alternatively: very thorough) and tend to be quite intimidating to newcomers. In addition, Microsoft made this more difficult by making the final version of Skype for Linux use the PulseAudio API directly, which was never intended by the original developers of PulseAudio.

I use skype quite a lot and have it set up to feed output to JACK and get input from a webcam microphone. I have not written up the technique that I use in an easy-to-follow format.

I suggest you start with the JACK FAQ (http://jackaudio.org/faq) which has some entries on getting non-JACK applications to interact with JACK. I also suggest you use google to lookup this set of keywords: loopback alsa pulseaudio jack

You will find various documents that describe how to do this - one or more of them will hopefully assist you.

maybe not the solution you are looking for but for the open source musicians podcast we did interviews using mumble. It has to be compiled with jack support, and you must find a server to use, Here’s a tutorial for compiling mumble for jack: http://linuxmusicians.com/viewtopic.php?f=47&t=11391
this will also require the interviewee install mumble, but they could just use the usual install methods. http://wiki.mumble.info/wiki/Main_Page

I was actually going to use another machine for the skype with a small usb audio interface on it. I want to do it this way because I could also get a phone running to my interface if I have this kind of setup. I basically just need a minux mix channel out of the interface on one of the outputs that isn’t 1 or 2, which are the main right now.

I have looked for tutorials online for how to do this. I understand the concept, I am just new to ardour specifically and don’t understand how to do the channel routing yet. I have set up a minus mix on this very piece of gear in FL Studio before. It’s just that the podcast network is ideologically opposed to running non-linux operating systems for, well, any part of the process.

thanks guys! the other info you gave me will surely come in handy soon.


So KXStudio seems to come with a great gui for routing the inputs, outputs, and internal audio… it’s called Carla. After I record tomorrow’s show and my new interface comes in, I will be giving KXStudio a go. If I get this done properly, I will post a tutorial on youtube :slight_smile:

Ardour has its own internal patchbay for this, too. No reason to have to use Carla (or qjackctl or patchage or …) but use whatever works best for you. It is the Linux way :slight_smile:

Carla and Claudia are great little tools… However Paul is right within Ardour you can patch pretty much everything…
I prefer to use the KXtools for setting up and saving complex MIDI routing options (often there is no software involved and my PC is acting as MIDI router and little else) , but I do most of my audio patching from within Ardour itself.

I ended up using Carla and I cannot be more happy with it. Everyone works differently though.

I am getting pretty good with the interface and if any of you have any questions about it, feel free to ask!