/ Register

Building a "sealed" box for 12" driver

Discussion in 'Amps and Cabs [BG]' started by BluesMan845, Dec 7, 2005.

  1. Dec 7, 2005 #1
    BluesMan845

    BluesMan845

    Oct 6, 2003
    Suffern, NY USA
    Hey guys,

    Does anyone have any experience with doing this ? When I was using my MB150S for gigs, I had an extra 12" driver from Carvin which was rated at 200watts RMS. I decided I would take the dimensions of the MB150's enclosure and build a box to put that extra speaker in. I built it out of 5/8" birch ply and glued and nailed the box together. The results were suprisingly good, actually very good. I've done some reading on the subject of cabinet building , but nothing serious. What I have found out is that building a sealed box is much easier than a ported one because you don't really have to worry about tuning the box to match the driver... (?)


    I would now like to build a new box for the same driver, but with 3/4 cabinet grade ply and use high strength epoxy adhesives and a protective grill to cover the speaker. Does anyone have any opinions on how to maybe build a better sealed box ? Does the size or depth of a sealed box effect the way the driver sounds ?

    john
     
  2. Dec 7, 2005 #2
    xyllion

    xyllion Commercial User

    Jan 14, 2003
    San Jose, CA, USA
    Owner, Looperlative Audio Products
    Sealed boxes tend to be less efficient than ported boxes. Ported boxes really aren't that hard to build. It all depends on how picky you are about the frequency response of the cab.
     
  3. Dec 7, 2005 #3
    BluesMan845

    BluesMan845

    Oct 6, 2003
    Suffern, NY USA
    Bob,
    The amount of volume I am getting out of the 700RBII/112 NEO combo which will power the homemade cab is more than enough to fill the size rooms we play. The efficiency of my homemade cab in this case isn't really a major concern as this cab is mainly for the guitar players benefit on the other side of the stage.
     
  4. Dec 7, 2005 #4
    smo

    smo

    Nov 3, 2005
    A Sandgropers' City, Australia
    Yep.
    Get a copy of WinISD - i used this to make a pair of 1x15's not too long ago. The program is a great tool, only take the results with a grain of salt - its not 100% accurate.(but very close in my experience. :)
    Whatever you do - DON'T make a cube! Standing waves will tend to bounce around inside a cube cab and interfere with the speakers' output - lessening clarity. (this may be marginal, but noticeable)

    The ideal shape ratio (does anyone actually adhere to this?) 'apparantly' is 1.6 (height) : 1.0 (width : 0.6 (depth). There is a way to get around this tho - I'd use just a little wadding in there, about a 1/2" thick, just to kick those standing waves - any cotton-like quilting material stuff will do, or even insulation batts since its a sealed box! :smug:

    At the end of the day tho - any shape other than a cube would be fine, just get the model no. on the speaker - plug it into winISD and work the curve till it's nice and smooth.

    Good Luck
    smo