-

Jump to content



Photo
- - - - -

Plate Amp displacement messes up calculations?


This topic has been archived. This means that you cannot reply to this topic.
5 replies to this topic

#1 of 6 OFFLINE   Chris A H

Chris A H

    Stunt Coordinator

  • 172 posts
  • Join Date: May 10 2002

Posted August 19 2003 - 03:23 AM

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 of 6 OFFLINE   Mika-H

Mika-H

    Stunt Coordinator

  • 78 posts
  • Join Date: Jul 14 2003

Posted August 19 2003 - 03:41 AM

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 of 6 OFFLINE   Patrick Sun

Patrick Sun

    Studio Mogul

  • 37,757 posts
  • Join Date: Jun 30 1999

Posted August 19 2003 - 03:44 AM

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.
"Jee-sus, it's like Iwo Jima out there" - Roger Sterling on "Mad Men"
Patcave | 2006 Films | 2007 Films | Flickr | Comic-Con 2012 | Dragon*Con 2012

#4 of 6 OFFLINE   Hank Frankenberg

Hank Frankenberg

    Screenwriter

  • 2,573 posts
  • Join Date: Oct 13 1998

Posted August 19 2003 - 04:42 AM

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

Yep.

#5 of 6 OFFLINE   Kyle Richardson

Kyle Richardson

    Screenwriter

  • 1,076 posts
  • Join Date: Jan 01 1998

Posted August 19 2003 - 08:48 AM

The volume displaced usually isnt enough to make an audible difference other than on the really small boxes.
Are the only options 1)make the cabinet bigger or 2) build an external box for the plate amp?
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.
Kyle Richardson
Acoustic Visions

AOL Instant Messenger Name: kyler70
MSN IM: acousticvisions@hotmail.com

#6 of 6 OFFLINE   Andrew Pratt

Andrew Pratt

    Producer

  • 3,813 posts
  • Join Date: Dec 08 1998

Posted August 19 2003 - 09:07 AM

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