Question:

Opus Octopus MCU300 - Master Control Unit

I am looking at this as a possible control unit for our house in Devon and would like to ask 2 questions:

1) Is there a limit at how many speakers you can have in each zone?
2) What is the difference beetwen Zone and sub-zone?

Answer:

If you use the Opus keypads for your amplification (which most people do) then you can run 2 Opus in-ceiling speakers from them, or a collection of speakers wired so that the resistance per channel is 4 ohms. However, there is a line level output (preamp out) from the rear of the keypads which you can wire down to a wall-plate with a pair of phono plugs on. This would allow you to hook up the output from the Opus system into a home stereo system or a separate amplifier with larger speakers attached.
You could wire one of these wall-plates in every room, or just in the main rooms where you would expect to want a louder/larger sound. This is also a useful way to wire in a subwoofer into the system.

As far as the difference between a main zone and a sub-zone is as follows:
A sub-zone is another zone in the system, so it has it's own keypad and speakers (or uses an Opus Active Speaker set). However, a sub-zone can only adjust the volume/tone of the music that is being played, it cannot control it. The music that is played in a sub-zone is the same as the music that is being played in the corresponding master zone.
Sub-zones are ideal for en-suite bathrooms, dressing rooms, conservatories, etc.

If 4 zones (+ 4 sub-zones) is not enough for your requirements, you can chain up to 4 Opus MCU300's together to expand to 16 independent zones.

This is achieved with a basic CAT5 cable and some audio passthrough connectors.