Identify Altec Voice of Theater speaker

[tony359]

Hi guys

Recently I was at a theater that has - the owner says - Altec VOT speaker behind the screen.

The left and righe channels are what I recognize as A6, with normal horn. The center channel has something I cannot recognize and I'd like your help.

I saw it only by side. The shape from the top is like the picture I'm attacching. The back of the speaker is open and inside I can see two cones facing the BACK of the speaker. I know that this speaker should not have ALTEC components anymore since they should have been replaced with cheaper ones once they broke .

The horn is a multicellar one.

And another question: since this speaker is open on the back, would be correct to install it in some kind of "sound wall" so that the back part of the speaker is in another room than the front side of it?

Thanks for your help.

Ciao