The minute you say "multi-zone"/"multi-source" you've said you're prepared for a level of complexity..or capability in your system that quickly (a) adds cost and (b) adds complexity. The complexity is generally found almost entirely under the subject of "what has to be done to program this beast". 6-8 zones and 4 sources, on the other hand is not a big system.
ADA, Crestron, Elan, and others can all deal with this size of system very nicely. System like ADA and Crestron, however, have a basic architecture that allows expansion way, way beyond your target. Due to this basic architecture, the baseline systems have build costs, and programming complexities, to support large endeavors.
Systems from Xantech and Niles are perhaps better suited both in cost and system size for your application. The other very excellent system is the Audio Control Director...very well thoughtout, very easy to set up, and very reliable.
Audio Control will sell only to installing dealers. Niles and Xantech you can get yourself from various sources. Setting up Xantech and Niles may not be the most intuitive experience, but, it can be done with patience.
If you are going to do it yourself, get a basic system working. Once you're comfortable with that (and have something working) then add the bells and whistles.
DEsign Cinema Priveewww.DEsignCinema.com
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