IMAX Sonics Speakers

[Fiat1]

Does anyone know the theory behind the speakers used in IMAX cinemas? I know they are made by Sonics and are designed to simulate a point source. What I want is some information on how such a layout works. The subs used are a massive bank of subs that face into a slot, why? I have included a couple of pictures of their speakers so you can see what I am talking about.

[Fiat1]

Here are the subs.

[soongsc]

Lots of speakers are also located behind the screen. The screen actually has holes in them to let the sound pass through.

One of the reasons I can think of having bass facing the slot is to let the punch of the subs expand more evenly so that prople sitting near the speakers don't particularly feel the speakers are beside them.

[abcdelihu]

hi friends, i have a question, this is a loudspeaker???
Imax - Eminence 18" Speaker -- 1610022 | eBay
i need a sub and i wanna 1 imax sub
friends i'll wait your answer, thanks

[sreten]

Originally Posted by abcdelihu

hi friends, i have a question, this is a loudspeaker???
Imax - Eminence 18" Speaker -- 1610022 | eBay
i need a sub and i wanna 1 imax sub
friends i'll wait your answer, thanks

Hi,

Its a raw 18" driver with no specifications, so generally not a good idea.

rgds, sreten.

[abcdelihu]

ok thanks bro

[hunter audio]

Hi

For starters , you could go to the support / publication / user guide sections of jbl , ev , tannoy and read up on all they have abt installed cinema sound .

Attached here some other latest files on enclosed area sound re-enforcement to generate interest . - sorry tried uploading but the files exceed forums 195 kb limit

Plus a good book on acoustics - this is all to address ones interest in acoustics

regarding the imax , cant help much at the moment - if possible - could you get hold of the contract between imax & sonics -specially the acoustics & measurements I am posting a sample of acoustic measurements carried out prior installation in an auditorium as an sample (in the next post)

suranjan dasgupta

[hunter audio]

Hi

Sorry a sample accoustics measurement is 4.9 mb cannot be attached here

[speaker dave]

I've seen the Imax speakers up close and they have a lot of interesting details and show evidence of good design.

The first picture shows 2 concentric horns, the treble horn is in the center of the mid horn. You can see that the horns are designed to have assymetry with a downward firing directivity. The two units seem to share the same shape, one being a scaled up version of the other. This gives them identical directivity, as you would want. I assume the foam bits help with directivity and response.

Placing the horns in the center of the mid bass, and one horn in the center of the second, is just good practice for maximizing off axis performance (least variation).

Slot loaded woofers don't change performance much but do allow for a lot of cone area in a compact volume.

David S