Plate Amp displacement messes up calculations?

Discussion in 'Home Theater Projects' started by Chris A H, Aug 19, 2003.

  1. Chris A H

    Chris A H Stunt Coordinator

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    So I get finished determining the size, shape and volume of my DIY Shiva, and now I find out that most plate amps are 4" DEEP! This displaces about 9% of my volume making the box much smaller!

    Are the only options 1)make the cabinet bigger or 2) build an external box for the plate amp?

    Anyone else have to re-do their box for the plate amp?
     
  2. Mika-H

    Mika-H Stunt Coordinator

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    Does this amp have a "box" containing the components or is it open (you can see all the components from the backside). If it is open, the only component that is really 4" deep is the transformer, but it is usually only a few inches wide, so in the end the amps components don't really take up any "real" volume.
     
  3. Patrick Sun

    Patrick Sun Moderator
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    Well, yes, if you want to stick to the tried-n-true designs, it's best to account for anything that would rob internal volume from the enclosure. If it's going to bother you, build a separate box for the amp and get on with enjoying your new DIY subwoofer.

    You could compensate for the loss in internal volume with some extra polyfill inside the enclosure, but that's a minor guessing game (as to how much to stuff inside the enclosure).

    Or just roll with the punches and hope that the added internal volume of the amp doesn't do too much to affect the sound quality. Also remember that at least 3/4" of the amp's depth will be volume not taken up inside the box, so the space it takes up inside is less than what you think it'd be.
     
  4. Hank Frankenberg

    Hank Frankenberg Cinematographer

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    Yep.
     
  5. Kyle Richardson

    Kyle Richardson Screenwriter

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    The volume displaced usually isnt enough to make an audible difference other than on the really small boxes.
    Or add a bit more polyfill which will make the enclosure just a bit larger to the driver than it really is.
    My suggestion is to not sweat it and try it out as is. If you want to add more poly after its built it is an easy 10 minute modification.
     
  6. Andrew Pratt

    Andrew Pratt Producer

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    Run the sims on the two box sizes and you'll likely not see much if any difference...esp considering if its sealed as you can always add a bit more stuffing. If its ported adding a bit of stuffing will help as well but as others mentioned you'd likely never hear the difference. Remember these box sizes are all determined by the TS parameters of the driver...and they're never perfect either so a little fudging here or there own't amount to much in the real world
     

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