[AE]

if you don't need to use an interface (in particular, if you don't need to record), you can select the zoom driver for the pro tools playback engine. i used this configuration for 4 hours of classes yesterday, and it works fine. super easy to manage.

soundflower (or blackhole) plus ladiocast (or loopback) will also work, but it's likely more complex than you need. ladiocast will occasionally drop a connection, which is a minor pain. these configurations will offer more options but are not necessarily useful for you.

if you need to use your interface (for example, if recording), you can create an aggregate i/o with the zoom driver plus your interface. it's a little tricky but doable.

if you're using an HD system, source-nexus is the only solution i'm aware of.