This solution will answer the following questions:

"How do I lock two (or more) zones together so they behave as one?"

"How do I send volume to one zone and have another zone go to the same volume?", 

"How do I have one zone follow another zone?",

"How can I make one zone always switch to the same source as another zone?".

"How do I make the subwoofer switch to the same source as the smaller speakers?" 

Any of the above is done by using the "Lock Zone" command. Let's assume the set of stereo speakers are connected to zone 1, and the subwoofer is connected to zone 2.

  • ^LZ @2,1$           ; zone 2 follows zone 1

Multiple zones can follow a master zone:

  • ^LZ @2,1$           ; zone 2 follows zone 1
  • ^LZ @3,1$           ; zone 3 follows zone 1

As with all commands that use the "@" to indicate a zone, you can also use multiple "@" in a command for multiple zones:

  • ^LZ @2@3,1$     ; zone's 2 & 3 follow zone 1

This is the same as the above two commands.

To stop following another zone, set the zone to follow to zero:

  • ^LZ @2,0$           ; zone 2 no longer follows another zone

Not all things are locked between zones, here's a the list of parameters that follow another zone:

  • Volume (and volume related stuff like Mute)
  • Bass and Treble (but not the EQ's)
  • Source changes

Anything not listed above, is not locked, notable things that are not locked are:

  • Equalizers, this allows using different setting for a subwoofer than for the stereo set.
  • Output Level, this allows adjusting the level of a subwoofer independent of the stereo speakers.
  • Lip Sync Delay, this allows a delay to be set to compensate for distances between the subwoofer and speakers.

Note: Changes to this command should be backed up in case of power failure by sending the "SS" command:

  • ^SS 512$              ; Backup zone settings