Seems to be the common problem of not enough information leading to numerous assumptions and misconceptions.
Distributed systems (lots of ceiling speakers) have their place and like any type of
system, can be properly or improperly applied or designed. The biggest advantage of distributed systems is usually that they can provide even coverage and good intelligibility in some environments where this might be difficult with other systems. I have designed several large training and
ballroom type systems that used high quality speakers such as JBL or Tannoy models that are essentially ceiling
speaker versions of their
monitor speakers and that put out well over 100dB of full range, high fidelity sound everywhere in the room.
However, most distributed systems are intended primarily for speech and/or do not use such high quality, and expensive, speakers. While proper use of zoning and delays can help, distributed systems are also often limited in being able to provide localization, relating the sound to a specific location, that can be desired for theatrical applications. As a high school
cafetorium that was done on a budget, I would guess that it is indeed a 70V distributed systems using fairly inexpensive speakers and was intended for basic speech and maybe background music use.
It is a common practice, and one I often apply in multipurpose rooms like this as well as in larger classrooms and presentation rooms, to separate the music and speech aspects by having a distributed
system for speech (for good coverage and intelligibility) and a stereo
system for program material at the
screen or
stage (for localization and full range response). So this approach by itself is common. It is the mixing concept and how that relates to the use that I still do not understand. As mixmaster noted, it sounds like you would just mix everything at
FOH using the
Mackie with the stereo output going to the
stage speakers and an
aux send via a DI or inline pad to one of the distributed
system inputs.
Charcoaldabs, what you describe sounds more like
front fill or perhaps dedicated effects or practicals. One concept that was common a number of years ago but that I have not seen used for some time was to provide a precedent
speaker, a single directional
speaker at the primary source location, in conjunction with a distributed
system. This was particularly applicable to churches where the distributed
system provided the coverage and
level while a precedent
speaker provided some localization to the pulpit. It may be that the
system you saw was using the
front fill or effects speakers to provide some precedence back to the actors or effects.