Projector mount sound isolation

[Esoteric]

Hey guys, so I have a client who has two Sanyo projectors mounted with Chief mounts, 1.5" pipe, and pipe flanges secured to the building steel.

The problem is that the bass drum hits on a frequency that makes the building steel vibrates and the vibration is being passed through to the projector and making the image jump.

Does anyone have any ideas on how to isolate the projector from the steel and stop the vibrations?

And yes, the projector must be rigged from the building steel in some way.

Mike

 

[sk8rsdad]

There are a few companies out there making isolation mounts. Maybe something like this would help.

Vibration Isolating Coupler - CMA347

 

[Esoteric]

There are a few companies out there making isolation mounts. Maybe something like this would help.

Vibration Isolating Coupler - CMA347

Thanks. Google is my friend.

 

[NicoDanger]

Vibration Dampening Advice?

Hello!

I am going out on a tour where we will be using a couple of 7k projectors. When possible we will be flying them on available overhead trussing/pipe but we plan to make it possible to ground-support them in the event that a particular venue does not have adequate overhead rigging.

In the past I have always tried to stay away from this. I work for touring bands that play loud music and sometimes those sub-frequencies can rattle your eyeballs. It's not a safety concern but I have had shows that were pretty much ruined because the projectors were literally vibrating. When you multiply that tiny vibration in the lens all the way down to the image hitting a surface, well, let's just say the result can make you seasick.

My question: Does anyone have advice on a material that I could use as a vibration dampener/absorber? I'm thinking of some kind of rubber mat or something that I could place the projector on so as to 'float' it off a hard surface. Has anyone done this? Am I toast any way you slice it?

Thanks very much,
Nick

 

[derekleffew]

Re: Vibration Dampening Advice?

If post #2's suggestion won't work, perhaps something from this thread: http://www.controlbooth.com/forums/...332-stabilize-bouncing-fixtures-catwalks.html .

 

[ruinexplorer]

Re: Vibration Dampening Advice?

When it is sitting on a surface, I have used Sorbothane sheets before.

Sorbothane is a proprietary, visco-elastic polymer. Visco-elastic means that a material exhibits properties of both liquids (viscous solutions) and solids (elastic materials).

Sorbothane is a thermoset, polyether-based, polyurethane material. Sorbothane combines shock absorption, good memory, vibration isolation and vibration damping characteristics. In addition, Sorbothane is a very effective acoustic damper and absorber.

 

[FACTplayers]

Re: Vibration Dampening Advice?

The reason it is vibrating is because the bass drum frequency is very close to the natural frequency of the material on which the projector is mounted. Every material has a natural frequency. Google it for more info and watch this video: Tacoma Narrows Bridge Collapse - YouTube

Anyways, to change the natural frequency, simply add some mass. Mount a piece of rubber or plastic between the projector and the ceiling. If that doesn't work, hang about 10# on the same mount as the projector.