Density of MDF, pine- and birchply

Discussion in 'Amps and Cabs [BG]' started by jock, Sep 17, 2005.

  1. jock


    Jun 7, 2000
    Stockholm, Sweden
    Anyone got any figures of these materials average weights?
    Im gonna build a 87 liter (3,07 ft^3) 2x12 and will most likely go for pine since it´s cheaper and lighter. I will also try a 12mm plywood and insted use a lot of bracing.
    What do you think this will weigh if the drivers weigh 13 kg together?

    BTW Im going for a vertical alignment of the speakers.
  2. I don't know the answer to your question but I think I would stay away from a solid wood like pine. The cab resonance would likely be strong causing it to diminish sound quality. That is bad. :(
  3. jock


    Jun 7, 2000
    Stockholm, Sweden
    Oh, I ment pine plywood. 12 or 15 mm thick. I was not clear enough, sorry. :bag:
    I wont use anything else than good plywood.

    BTW How thick is the plywoods used in normal cabs like Eden, SWR etc?
  4. Crockettnj


    Sep 2, 2005
    North NJ

    i have heard this many times. has / does anyone have actualy experience with cabs made from solid woods? thiing is, i have a great source of solid woods i can get for a great price (favor owed to me). I am considering using them for a 1.5 ft3 full range cab, but keep hearing baout how bad they woudl be.

    isnt it possible that it woudl enhance the sound? better yet, oculd someone educate me as to WHY a good solid wood, properly chosen (?) WOULDNT enhance the sound?

    thanks a ton.

    (lastly, what is generally considered the very best wood to use for bass cabs? MDF?)
  5. Monomer


    Jul 22, 2005

    the cab would:

    -weigh a ton

    -warp/crack during season changes

    Birch ply would be my pick.
  6. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Solid wood doesn't have the rigidity or strength that plywood does. Splitting is a concern. It's fine for small hi-fi cabs but not so good for pro-sound.
    Most manufacturers use 3/4" (19mm) plywood. Properly braced 1/2" (13mm) works better and is far lighter but the differential in the cost of 3/4 versus 1/2 is slight, while the increased labor cost involved in building a well braced versus barely braced cab is major.

  7. Yup.

    Hardwood ply is the best option in terms of the compromise between density, strength and weight. MDF is great if you don't have to move it. Material density and rigidity is important in cabinets because you want to limit resonance in the wood. If the wood resonates it will manifest itself as ringing and have a negative effect on the cab's sound. Another thing to consider is a something-other-than-rectangular shape to help limit standing waves inside the box.

  8. Properly finished MDF won't warp or crack. We use it for our cabinets and the climate here is erratic and has some extremes to say the least. We also have them shipped by sea from Denmark with no problems.

    It would weigh a ton though...:D
  9. MDF is 49 pounds per cubic foot, or 98 pounds for a 4x8x3/4" sheet.

    Baltic Birch is 32 pounds per cubic foot.
  10. Petebass


    Dec 22, 2002
    QLD Australia
    Yep. I also MDF for anything that doensn't have to be portable, and braced 12mm ply for anything that does.