Plain nonsense, put two loudspeakers above oneanother and you have a
vertical line array, a short one, but it is valid.

Well, I'm only repeating what the L-Acoustic and Martin sales reps told
us when when sent them the plans of our auditorium.

What they probably omitted to tell us was that _their_ line array were
not suitable for our size auditorium, and then generalised that to line
arrays in general.

Example, not endorsement: see http://www.slsloudspeakers.com

One of our prerequisites is that whatever speakers we buy, we need to
have a trial run first to actually here what they are like in our
environment. Some companies have been willing to accommodate this,
others have not...

WHAT a "such a system"?

As shipped by L-Acoustic or Martin

A ribbon loudspeaker constitutes A line array.

Would such a setup be suitable for a church auditorium of 2,500m^3 with
the audience sitting between 4m and 15m from speakers hung from the rafters?

It doesn't have to be a full size stadium PA to constitute a valid line
array, the ones used in that context are btw. bent so that the audience
can still get a balanced sound - and not an insanely loud sound - close
to their "foot".

L-Acousrtic recommended that we trial some 112XT's instead of their line
array speakers. We found that whilst the sound quality could not be
faulted, the people sitting near the back (approx 12m away) had a
comfortable sound leve, whilst the people in the front got drilled.

Also the 90deg conical directivity of the 112XT's created other problems...

Chris W

--
The voice of ignorance speaks loud and long,
but the words of the wise are quiet and few.
--