Best way to set up Talkback?

What interface do you have? The reason I ask is with my RME Fireface 800, for example, I can set up a Talkback without needing to involve Logic. Some audio interfaces's driver software allow you to do that in their routing.

ok...shooting blind here (away from my Logic machine)...

Hook up your talkback mic into one of the (probably) XLR inputs on the back of your 1804. Then in the audio layer of your environment, set up an audio instrument with the EXTERNAL instrument. Configure it's inputs to whatever socket you plugged the mic into, and it's outputs to wherever your headphone mix is going. Name this instrument TALKBACK or something equally as obvious. I don't think it even needs to be in the arrange page list. If I am right, you should have your talkback mic "hard"wired into your system. You can then set compressors and stuff to similar settings to those in the article you linked to, and off you go.

If I am wrong here, someone more clever will certainly point you back in the right direction.

With all the ins and outs you have, there is great flexibility for creating a number of discreet stereo headphones mixes using the sends on each audio channel in pre-fade mode. I often need 3 different mixes, excluding mine and logic makes it simple.(ish)

with the external instrument you don't have to record arm it, and thus record stuff on it if you go into record mode... just a thought 🙂