How to connect Ardour to JACK in a multi-domain JACK system

Typically a single audio jack domain is sufficient. The default domain is called “default” (jackd -n default). By default all applications connect to the “default” Jack domain directly with Jack API or with an ASIO (Windows) or CoreAudio (OSX) driver.

In the case of a second Jack domain (jackd -n default2) how can Ardour be connected to the secondary domain?

This question applies to the various platforms (Linux, Windows and OSX).

You can use the JACK_DEFAULT_SERVER environment variable.

I used to jackd -n debug -d dummy & ; JACK_DEFAULT_SERVER=debug ./ardbg to debug Ardour, back in Ardour2/3 days before Ardour had its own dummy backend.

Ardour has no mechanism to connect to an alternate JACK domain. You would need to modify the code to do so.