Subwoofer enclosure made of plexiglass

Discussion in 'Home Theater Projects' started by Nick_C, Sep 3, 2004.

  1. Nick_C

    Nick_C Auditioning

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    Hopefully I picked the correct forum.
    Anwyays, a friend of mine has an 18" movie theater subwoofer (8 ohms). He was thinking of getting rid of it but I talked him into keeping it and using it as a new HT sub. It will most likely be powered at 240 watts (at 8 ohms).

    He would like the box to be made of plexiglass. I'm not too thrilled on that idea, but it's his HT sub. So I was wondering what kind of box design would be best for this subwoofer, what kind of glue would be needed to put it together, and what would be a good way to attach the sub to plexiglass?
     
  2. Dave Milne

    Dave Milne Supporting Actor

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    Material doesn't affect the box design. Determine the design type, volume and port dimensions (if used) with your favorite simulation software and just build it out of Plexiglas instead of plywood or MDF. Plexiglas can be worked like wood, with sharp, fine-toothed tools and slow feed rate to prevent burning/melting. The tricky part is polishing all of the edges. Otherwise they look rough and milky-opaque. This is a lot of work!

    You'll want to use 1/2" or thicker plexiglas and let me warn you in advance, this stuff is not cheap. I'm guessing roughly 10 X compared to 1" MDF.

    There is a company in California that specializes in custom Plexiglas sub enclosures for the autosound market. You could probably get their link from one of the car audio forums like sounddomain.com. Of course, this will be even pricier than the DIY route. Probably $300-$600 for an average sized enclosure.
     
  3. Darren_T

    Darren_T Second Unit

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    I think bracing is going to be key here...plex flexes quite a bit. 1" or more material might be sufficient to eliminate major flexing though.
     
  4. Dave Milne

    Dave Milne Supporting Actor

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    You'd be surprised. 1/2" and thicker plexiglas is quite rigid. I don't have modulus numbers on hand, but I would guess that it is actually stiffer than MDF or plywood.

    Oh, and outlets that sell thick plexiglas (plastics supply wholesalers mostly) have special glues that you can buy for this
     
  5. Cam McFarland

    Cam McFarland Supporting Actor

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    Edges ARE alot of work & if not done properly can
    really affect the look of the product. There are also
    ways of polishing the edges with a torch, but it takes
    a little practice.
    As far as the glues, it more or less melts the edges together, & you should be able to get it where ever
    you buy the plexiglass.
    As far as attaching, I presume you would just make a baffle out of plexiglass with holes cut for the driver & bolts.

    Mixing clear & colored plexglass would make quite an
    interesting enclosure......
     
  6. Mark gas

    Mark gas Second Unit

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  7. RobLJ

    RobLJ Stunt Coordinator

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    If you're looking into plexi, I'd get a quote from GatelyAudio. He's real experienced and makes beautiful enclosures.
     
  8. Christpher_S

    Christpher_S Stunt Coordinator

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    Do you know the TS parameters for the driver your friend has? If not, I would suggest getting rid of it and picking up a driver that you can model with one of the box design programs.

    This has nothing to do with the material you use for the enclosure but the potential is pretty high for building something that sounds like crap if you just build a big box and stick the driver in it.

    My apologies if I'm stating the obvious and you do know the specs on the driver.

    -Chris
     
  9. Mark Hayenga

    Mark Hayenga Supporting Actor

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    Find the nearest custom aquarium builder...
     

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