JACK sound server and Routing Audio Tracks in Ardour

Routing Audio Tracks to Master Channel

This section will illustrate one of the most important functions in Ardour mixing –routing audio tracks. When you launch Ardour, at first there is only one channel that appears. This is called a “Master” channel, see below:

master audio channel in ardour

master audio channel in ardour

This master channel will combine all audio in the multitrack environment and then output a “Master” stereo track (left and right channels). The audio inputs to “Master” channel could be any track or bus (e.g. the bass guitar, drums, vocals, or existing recordings in your drive). The difference between “track” and “bus” is that “bus” takes input from outside Ardour (like when you are recording using your computer hardware audio interface). “Track” can be used to load audio which are already recorded (example from Tape source or previous recordings save in your hard drive). Track and bus can be overwritten or altered by re-recording. Both are treated equally by Ardour and can use plugins , etc. It could also be a mono (one-channel) or stereo (two-channels) based audio. Supposing you are doing multi-track work of a stereo recording of bass guitar and kick drum track. The input-output diagram to “master” channel are as follows:

input and output diagram in Ardour

input and output diagram in Ardour

Discussion: In Ardour, the master channel accepts two unique inputs: In1 and In2. For example, to input the bass guitar stereo audio you need to route Out1 of bass guitar to In1 of Master Channel and then Out2 of Bass guitar to In2 of Master Channel. The master channel then combines all signals found on its input and then route it to Out1 and Out2 for playback. This is the one you can listen in your studio monitors. Out1 and Out2, specifically are outputs of your audio device or soundcard. So how can you actually route audio tracks in Ardour environment? This is the time you will be using the “Show Mixer” feature (Go to Window – Show Mixer). This is how it looks like:

Show mixer feature in Ardour

Show mixer feature in Ardour

In the above mixer, there are two track inputs, namely the “kickdrums” and “chorus bass”. On your right you will see the “master” bus. To edit the master bus input, simply click the number below the word “master” (which is 4 shown in the screenshot above) and then click “Edit”. Why the number is shown as 4? It is because since there are two stereo track inputs (bass and kick drums), all in all there are 4 mono inputs to the master channel (Bass guitar out 1, Bass guitar out2, Kick drum out 1, Kick drum out 2). After you click “Edit”, you will see the following:

master input channels

master input channels

The input tracks shown under “Master Input” is exactly the same as depicted on the input diagram shown earlier. Under “Available Connections” there are two tabs: “Ardour” and “System”. Ardour tabs means that it shows connections that are only available inside Ardour environment. Example of these connections are: kickdrum/out 1, kickdrum out2, chorus bass/out 1, chorus bass/out 2, etc. “System” connections are those found outside the Ardour environment. Example of these connections: “Capture_1” and “Capture_2”, these are inputs coming from your soundcard for example. To add inputs to In1, simply click “In1” tab and then click which connection you would like to add either in “Ardour” or “System” based connections. Do the same for In2. To remove inputs, just click the track input under In1 or In2. Now you are familiar with the Master Input, close this window and then go to Master Output. This looks similar to Master Input only that it shows all possible output connections:

Master channel output

Master channel output

In the master output, since you would like to monitor the playback to check how your mix should sound like, the output is then routed to “system:playback_1” and “system:playback_2”. These are soundcard outputs which is then feed to your studio monitors. These are basic Ardour routing techniques which of course can well be extended to your other tracks, busses, etc aside from routing to master channel.

Content last updated on June 27, 2012