ELK Listen-in speakers


My Elk install is going well, should be in new house in a couple of weeks.
I'm confused about the listen-in interface. I have 3 listen-in zones and will use one as a front door speaker/mic set up for answering the door when away.
Since the Speakers hook up to OUT1, it seemed to me that they would broadcast all Messages from the M1G (not what I want going out on the front porch). I was told earlier here that they would announce only if I wrote a rule to turn them on when the audio amp turns on (ie turn on output 7 when audio amp on)
Now installed, they do indeed speak all messages. Do I have them hooked up correctly or is this the way they are supposed to work? Anyone out there using the 2 way listen in?
If this is correct, then is the best way to use a relay to turn on the front door speaker only when I want?
Any speakers you want to turn off, put a relay in the speaker line and control the speaker from Rules.