best speakers for hall

[ia9]

Hi,

What ceiling speakers would you guys recommend for a school hall. 54ftx20ft. Height 9ft. (wooden ceiling, wooden floor)

Main usage is: assemblies, question and answers. Also, hire for community use for conferences, lectures etc.
No music.

What brand and size speakers will be best, need quality sound.

Connecting to 8ohm system.

Thanks,

[Cal Weldon]

Can you please draw a picture of the layout of the room including seating and podium.

[ia9]

Hi Cal,

I've attached rough scetch. The hall does not have podium. Just straigt rectangular.

The wiring is done for a 100v system.
We are thinking of having the hall on a separate 8ohm system and have the rest of the school on the 100v system.

Really confused about what to do....

Thanks

[Cal Weldon]

I am hoping that those with more experience than me will step in here. I was getting things started by having you post the layouts. Are we looking at two different rooms?

[ia9]

Thanks Cal,

There is 1 hall. The pictures may look different because they were taken during and after refurb.

The rest are classrooms.

[simon7000]

No, he is showing the entire school. He just wants "Better" speakers for the main assembly hall. The problem of course isn't the speakers, it is the room. Without any acoustic treatment, nothing will work.

Wavey will suggest long column speakers which would be the best normally except the ceiling height is way too low. The other problem is they don't ceiling mount.

When using ceiling mount loudspeakers the only issues are coverage and volume. With a 9 foot ceiling and people seated you have a 5 foot speaker to ear distance. So that would require a maximum spacing of speakers 10 feet apart. So at 54 x 20 feet you would do two rows of six speakers each.

Now as to volume at a maximum distance of about 11 feet to any speaker, even if you designed for NHL Arena volumes that would require 115 dba peak levels. Allowing for thermal compression you would design for 118 dba. Typical ceiling speakers are at least 90 db/w. Room "gain would add at the very least 3 db back so you would require 300 watts or 25 watts per speaker if you really wanted to be that silly. Dropping 10 db would require 2.5 watts. So a 100 volt speaker system makes sense.

Even with real acoustic treatment you would require 5 watts per speaker. To get better LF response out of the speakers you would use a 10 or 15 watt rated transformer but only at the 5 watt tap. Of course better LF in a room like this is not really a good idea.

So the request for advice on speakers is, what is there is not as bad as it seems. The room is worse than most.

[ia9]

Sorry, there are no speakers in at the moment. The diagram just shows where there is wiring done for speakers. Nothing has actually been fitted. So you advise having 100v system throughout instead of hall 8ohm and rest 100v.

Also, what brand ceiling speakers are best?

Thanks

[simon7000]

JBL :: Product

Use the 15 Watt taps.

[ia9]

Simon , thanks a lot.