Start with 1 Mac (2 outs), 1 audio interface (6 outs), 1 speaker emulator (2 outs)
Take a Garageband or Logic Pro mix and direct it to your momentary output of choice. That usually means change a preference, apply the changes, continue working.
Wouldn’t it be great if that was a one-click operation?
Open Audio/MIDI Settings. Click on the little + icon in the Audio window to add an “Aggregate” device (not a “Multi-output” device – that drives all the outs at once). In my case I added the Mac outputs, the Scarlett interface, and my VRM box. I don’t see a way to cause the order to change, so I named it “mLRsLRLRLRvLR” to help me remember what order the outputs are in. Logic Pro lets you provide your own labels for the ports, so it can be a lot easier.
In Logic I open a new project with a single track, Audio or Software Instrument will do.
Route the output of the Audio track to an Aux (creates the bus)
Route the output of the bus to each in succession
1/2 for the Mac outs
3/4, 5/6, 7/8 for the Scarlett
9/10 for the VRM box
Now we have 5 output pairs that we can switch to by routing the Aux to the appropriate pair of outs.
I place inserts on the Aux so they don’t have to repeat. I place an Channel EQ on each set of outputs just in case I want to adjust.
Now I can listen on the main outs (Mac speakers or AV monitors connected to the headphone jack), external monitors with a simple plug on the patch bay to route L to the grotbox along with setting the output to mono, headphones (open back) for bigger, different sound, or the other set of headphones connected to the VRM box that gives me room emulations.
If I want the “big speakers” in the living room I still have to do a “manual” switch to Airplay to get the sound to the living room, but that’s acceptable. Easy to do with a bounced track and playback to both office and living room.