I have recently seen a large 400seats cinema without (!) subwoofers ( I have 2 18" in my home theater ) , just 3 mains (KCS speakers).
But I wonder what you usually have for your theaters, say the 200, 400, and 600seats or so. (how many subs and what power you feed them AND if you high pass them and at which frequency usually, 30hz? 25hz? 20hz ?).

The system is powered by two QSC amps running at 6KW for the combined power of both systems.

Josh
 

hi

that's very nice !! you don't seem to have headroom problems.
 

Thus, I have used anywhere from a single 18" up to eight 18" subs.

Seat count isn't so much the issue as volume of air one needs to move. If the room is big, you need to move alot of air. As to the high-pass, yes I high pass my subs based on what they can play. Also, I'll high-pass a sub system to keep those frequencies from passing through a wall too much.

I think you are asking for rule-of-thumb questions that there are no rule-of-thumb answers. I will say that the vast majority of theatres I've seen often under-sub the the theatre. But, then again, they even more often fail on making good walls so it is probably just as well.

Steve

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"Old projectionists never die, they just changeover!"
 

not a rule of thumb, just a small poll among the pros here , to have an general idea, sort of, of what you use. if money was not an issue, we would see much more headroom ( subs, amp power ) indeed but the walls issue is also to be considered as you mention: one does not want to have U571 blasts go through the next theater showing Kate and Leopold

The nr of spectators present in a theater plays also an important role: human beings absorbs a lot of energy. 4 subs with 1000w each in a 400-seat theater do not sound the same when it's full or 1/3 full...
 

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Adam Fraser www.pinestheatre.com