Recessing Subs

Systems Posts: 14,872
edited December 2002 in Custom Fabrication
Building a custom glass box, and was wondering how you make the cut out around the hole to recess the sub into the material for a more finished look. I have a router and some bits, but it would seem to me to become difficult to make a perfect circle. Any help greatly appreciated.

Also a side question. I am trying to use fiberglass jelly instead of the resin. Is there a downside to doing this for a MOMO enclosure?. It seems to not be as smelly and not nearly as messy. I don't see a downside to final drying but I figured i'd ask because you guys know what you are doing..:)
Post edited by Unknown User on


  • PoweredByDodge
    PoweredByDodge Posts: 4,185
    edited November 2002
    well i'm definately no expert on glassing, however i can tell you this... every glass box i've seen has had one thing in common, there was an mdf or plywood "ring" that the sub was screwed to...

    it was a ring that had the center cut out so the sub dropped in, and then was maybe 2 inches "wide" ... the sub was screwed to the ring and then the glass was built up about 1/2 - 3/4 inch all around it so that it came out "flat" and the subs look recessed.

    i'm sure somebody who does this more often could give u a much better answer, but if nobody gives you any heads up then check out and look at their demo car install in the blue Acura Type R --- they have detailed pictures of what they did to build their subwoofer boxes, and those boxes came out "recessed" / flush mounted.

    good luck
    The Artist formerly known as PoweredByDodge
  • Josh
    Josh Polk Woodpecker Posts: 792
    edited November 2002
    Select products sells MDF ring templates. You can use those in conjunction with a flush trim bit to get a perfect circle. If you want to flush your subs, cut out a ring made of one inch MDF and then use a rabbit bit to flush the subs. I suppose fiberglass jelly would be okay. I've personnaly never used it, but if it makes the 'glass hard, then it works.
  • djsSHO
    djsSHO Posts: 36
    edited November 2002
    Thanks for the info. I will probably order those rings. I work at a hardware store, you'd think i woulda saw the router bit to do it....oh well..:)

    Do you just use the ring templates to trace new circles in mdf or is there some other use to them????

    I have always used a Roto-zip tool with a circle cutter. It cuts perfect circles every time. Was just wondering what was special about the mdf rings.

    I am checking out that alpine site and I want to learn how to do all of that crazy stuff. I'd love to do that for a living. I have done some custom things for my car, but that's just insane!!
    Derek S.
    1994 MTX SHO
    Polk MOMO 12"
  • PoweredByDodge
    PoweredByDodge Posts: 4,185
    edited November 2002
    ya alpine's got a helluva good / insightful install team... but they lose a lot of credit in my eyes --- most of their vehicles are NOT street legal -- and they tell u that.

    while the fabrication is never easy -- and dont get me wrong, i'm not discounting the artworkthey do -- it is still more important to me to see someone do that same wild / in depth / awesome install, but do it in a manner that is street legal --- that preserves the original safety equipment and bolts / braces / installs everything in a manner that is perfectly safe and enjoyable..

    i mean --- think of it thisway, car audio is not for looking at -- its not for sitting still --- it is for driving down the highways and backroads of the world blasting tunes that make the trip enjoyable.

    maybe that's why ALpine Type R coaxials are built in the most retarded way i've ever seen a speaker built (the crossover is plain black basic piece of junk that's OUTSIDE the speaker --- off a 3 foot length of wire --- I mean yes u can bi-amp them, but there are better ways to integrate that system)... they're concept of reality is flippant if not worse.
    The Artist formerly known as PoweredByDodge
  • Keske944
    Keske944 Posts: 134
    edited December 2002
    Another thing that you can do is use acrylic instead of glass. It is stronger, lighter, easier to work with, cheaper and all around better. You can usually find custom acrylic dealers in the yellow pages under plastic. I am haveing a custom cut 41" x 27" 1/2" piece of clear arcylic cut to fit my trunk perfectly for about $135 If you are using acrylic and want that "Perfect" look talk to an acrylic dealer. They are usually willing to work with you and can get you just about anything you want. They would be a great source for more info on your fiberglass jelly too.
    Patience... patience...

    Screw patience... Crank the volume and floor it you panzie.