IB impact on screen?

[inscrutable]

I've just started thinking about details of theater construction in new house. Thinking of a single ceiling-mounted manifold versus two (either side of room) wall mounted manifolds. Haen't done any calcs/modeling yet, but I'm guess-timating 8 drivers.

If they are ceiling mounted in a single manifold four on a side opposing/facing each other, will the resulting/remaining mechanical vibrations cause any impact on a nearby ceiling mounted screen (only perhaps two feet away) or projector (about 16-18 feet away). I may end up wall-mounting a fixed screen, and that potential problem probably goes away. projector must be mounted there, but is not attached to same ceiling joists/rafters, so I'm not anticipating an issue there either.

Whaddya think? TIA!

[ThomasW]

Whaddya think?

I'm thinking I need to get the FAQ pages updated with info about how one models room modes. That way people can begin to see what happens when subs are installed in a room.

There's a current thread where 2 line arrays were installed in separate positions on one end of the room. He's having cancelations issues due to a standing wave being created by the interaction of the subs. This is to be expected when subs are placed more than 1/4th wavelength apart.

The effects of manifold IB's on the screen/projector, with be the same as those created by having a regular sub placed in a similar room position.

There's one install in the gallery where 4 manifold mounted 18's share ceiling with a CRT projection system. That install has no problems with the PJ or screen vibrating. And CRT PJ's are far more sensitive to problems assiciated with vibration than digial PJ's

[JeremyG]

Hopefully Kingdaddy can chime in on this. I've seen his HT with 4 Avalanche 18's in a ceiling manifold in a very small room with a projector and motorized screen and there is no movement, jitter or distorted image. Other than my eyeballs shaking.

Jeremy

[inscrutable]

Thanks Thomas and Jeremy. I must confess to seeing something of a response to this in the FAQ after I'd already posted it. I am leaning toward a single manifold for other reasons, in addition to the cancellation one.

One of my next posts - after some scouring and searching this time - would be to the effect of what can I use to model for design of these beasts in my room?

Tim