Ceiling Mounted Projector and Ceiling Mounted Infinite Baffle Subwoofer - Dustin B???

Discussion in 'Home Theater Projects' started by Kevin Deacon, Dec 16, 2004.

  1. Kevin Deacon

    Kevin Deacon Second Unit

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    Hi, I recently purchased an InFocus 4805 Projector and as of now it sits on the coffee table.

    I have an Infinite Baffle subwoofer mounted between the rafters in the ceiling between my main speakers. It consists of two 15" drivers facing each other in a 22"x22"x17" box with a grill covering the opening in the ceiling. The rear of the drivers fire into the attic.

    I never thought I would own a projector and my major concern is when I mount the projector on the ceiling I may have vibration issues with bass heavy scenes. This sub will put out a freq of 10Hz at around 90 decibels which is impossible to hear, except for objects rattling. The floor, and I have to assume, ceiling vibrate quite violently.

    Do others have issues with floor standing subs causing the ceiling mounted projector to vibrate?

    Dustin B - you have a projector and a sonotube sub. Does your projector vibrate with low freqs???

    Is there some kind of mount available that will de-couple the projector from the ceiling? I wonder if there is a DIY solution. Does any one have advice, thanks.

    BTW, removing the subwoofer is not a solution. Best bass I've ever heard.

    Kevin
     
  2. Andrew Pratt

    Andrew Pratt Producer

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    If you mount your PJ to the joists above the ceiling it shouldn't vibrate any more then it would elsewhere. I had my IB mounted to a side wall and the ceiling mounted PJ never showed any signs of vibrating...nor does it now with the Tumult pounding away [​IMG]
     
  3. ThomasW

    ThomasW Cinematographer

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    One guy has a ceiling mounted IB with a 4 BP-1804 manifold with the outlet between a ceiling mounted CRT projector, and his screen. He's not reporting any major problems.

    I also have a ceiling mounted CRT projector. My IB of course is floor mounted and there are no vibration issues.

    If you do have any issues I'm sure we can solve them.
     
  4. Kevin Deacon

    Kevin Deacon Second Unit

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    I should have been more clear. The IB is mounted as close to the center of the room as the trusses would allow. When I hang the projector it will also be close to the center of the room, thereby using one of the same trusses that the IB is mounted between. I will know this weekend if there is a problem.

    Maybe having the image vibrate will lend to the low freq effect[​IMG]
     
  5. Dustin B

    Dustin B Producer

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    I'll report the same as the others. I've had no issues with my sub vibrating my projector.

    With the drivers facing each other they'll cancel all mechanical vibration to the trusses. So all that will be left is the bass energy which from the experience of myself, and others here with significantly more powerful subs, won't be a problem.
     
  6. Kevin Deacon

    Kevin Deacon Second Unit

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    Last night I put my hand on the ceiling during parts of Lord of the Rings and there was much vibration. I don't buy into the theory that when the drivers face each other they cancel out vibration totally. Or does the ceiling vibrate just from the bass energy? My god that's a lot of energy. We'll see on Saturday.
     
  7. Dustin B

    Dustin B Producer

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    Yep, that's just the bass energy, and yep it is a lot of energy.

    Even with Saskatchewan 50s house countruction, when I turn my system up I can go outside, put my hand on the wall and feel it vibrate.
     
  8. HowY

    HowY Extra

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    If this is on the top floor
    use the roof truss instead of
    the rafter...

    The other option would be to fashon a
    suspension system for the projector
    where some type of spring system
    holds the platform the projector
    rests upon. As opposed to hard
    fixing the projector itself.

    This method is used with expensive
    servers to "isolate" the platter
    rotation of the hard drives but
    they use an oil filled dampner.

    Same theory applies 'tho allow
    the platform to move independant
    of the mounting hardware.
     
  9. ThomasW

    ThomasW Cinematographer

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    Of course. And it will do so when excited by any the energy from sub. The amount of wall/ceiling flex depends on how well the house is built.

    Ceiling mount your screen and they'll vibrate at the same frequency ......[​IMG]
     
  10. Kevin Deacon

    Kevin Deacon Second Unit

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    Thomas, Dustin said this:

    I'm using neoprene washers on the projector mount. We'll see!
     

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