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acustic material (in cabs)

Discussion in 'Amps and Cabs [BG]' started by srbguitar, Oct 4, 2002.


  1. srbguitar

    srbguitar Guest

    Jul 19, 2002
    Fremont CA
    my question is if i should put acustic material in a 2x15

    i just bought a 2x15 and there is no aucustic material in it. if i do put acustic stuff in it will it make it sound deeper with better lows? also if i do what kind and were do i get it? also were should i put it inside the cabinet?

    thanks for the help.
     
  2. A lining of the inside surface reduces the amount of high frequency reflection bouncing around inside the cabinet. I doubt you will hear the difference for electric bass.

    Stuffing the entire cabinet with fiber fill material at the ratio of 1 pound of material per cubic foot of volume, will make the cabinet appear larger than it actually is, by about 30%. This is a nifty trick that is very useful for making small sealed cabinets perform like cabs that are 30% larger.

    If you have a vented cabinet, stuffing will screw up the tuning by moving the tuning frequency lower. The exact amount cannot be predicted in a vented box, and must be determined by measurement.
     
  3. srbguitar

    srbguitar Guest

    Jul 19, 2002
    Fremont CA
    thats just what i want(elimenat the extra highs produce by the 2x15 cabinet) because i have a seperate cab for the highs.

    so how do i determin how much stuffing to use if it is vented? the demensions of the cab are 34.5 inches wide 17 inches high 12.5 inches deep
    thanks alot. the two vents have a diamiter of 4 inches
     
  4. Ok, given the measurements of your cab, the internal volume would be approximately 2.96^3ft(cubic feet) not counting speaker displacement and any bracing that the cab may have on its interior. Like mentioned in the post above, it is rule of thumb to use 1lb per cube. that would mean you need three pounds of stuffing layed loosely throughout the cab. I tend to pay close attention to the back wall of cabs, for that is a trouble spot for standing wave interference, especially if the cab has no angled surfaces. And most of the time, they don't.

    Hope this helps,

    KERM
     
  5. srbguitar

    srbguitar Guest

    Jul 19, 2002
    Fremont CA
    ok i think i almost got it

    so i would use 3 pounds of stuffing but what kind and were to i get it.
     
  6. My wife works in a fabric store, and she gets it for me in 1 pound plastic bags.
     
  7. patrickj

    patrickj

    Aug 13, 2001
    Baltimore, MD

    What's the advantage of stuffing a vented cabinet?

    actually, nm, misconclusion (word?) your above post

    http://nightshift.net/speaker_filling.htm
     
  8. If you have test equipment and a lot of patience, you can reduce the required volume by about 30% by completely stuffing the cabinet. This technique is well documented for use in sealed boxes, but is very sketchy with vented ones. Vented cabs are far more complex in their behavior, so the effect cannot be estimated with any accuracy.

    My approach is start with an optimum sized and tuned cabinet. Reduce the internal volume by placing 1 cubic foot non-compressible filler inside the box. Stuff the remaining volume at 1 pound per cubic foot, then measure and record the system tuning and response. Be sure to not block the internal vent opening. This is strictly a trial-and-error approach using many iterations. Once the optimum is identified, a second cabinet of reduced size is constructed and filled with stuffing.