ProAudio: Locking two (or more) zones together so they behave as one (Control 4)

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" parameter (see picture below)

Once the zone is selected using "Select Audio Output", scroll down to "Lock Zone" and set it to the zone you want this zone to follow. 

For instance if you have a set of stereo speakers connected to zone 1, and a subwoofer connected to zone 2, you would set "Select Audio Output" to zone 2, and use "Lock Zone' to lock it to zone 1. Now each time zone 1 changes sources, zone 2 will also change sources. When the volume is raised on zone 1, zone 2's volume will also be raised.

More than one zone can be lock onto a zone. For instance after the above zone is setup, and could then Select Audio Output '3', and set the Lock Zone Setting to '1'. Now each time zone 1 changes sources, zones 2 & 3 will also change sources. When the volume is raised on zone 1, zone 2 & 3's volumes will also be raised.

Not all things are locked between sources here's a the list of locked parameters:

• 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 are 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 going to Composer's Action Tab and pressing the "Backup Audio Settings (except volume)" button.