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OBC115 - What should I use for damping material?

Discussion in 'Amps [BG]' started by negativefx, Nov 26, 2013.


  1. negativefx

    negativefx complete hack Gold Supporting Member

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    Was thinking about replacing my OBC115 with another 410 but decided to dampen it first and see how I like it. What material/product should I use?
     
  2. will33

    will33

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    Quilt batting, mattress pad foam or any type of insulation, though that stuff is itchy.

    One layer of the mattress pad foam will do it, or layer up the quilt batting to somewhere between 1" and 2" thick.

    If you use matrress pad, make sure it's the regular cheap stuff you can easily blow through, like an air filter. Not memory foam or any other type of "closed cell" material. If it can't pass air easily, it loses it's damping properties and actually takes up space, effectively shrinking the size of the box inside.
     
  3. P-oddz

    P-oddz Supporting Member

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    If you do this, let me know your results. I've got an OBC115 sitting at home, and would be curious if this affects in a positive/negative way.
     
  4. negativefx

    negativefx complete hack Gold Supporting Member

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    If I would have asked this question 30 minutes earlier I would have had an old mattress pad on hand. Garbage was picked up 15 minutes ago. :p
     
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  6. negativefx

    negativefx complete hack Gold Supporting Member

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    Will standard gray egg crate foam work?
     
  7. steve_rolfeca

    steve_rolfeca Gold Supporting Member

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    If you're going to line it, be sure to keep the lining at least an inch or two away from the inside mouth of the port. Otherwise, you'll mess up the port performance.

    Try huffing through the foam that you're thinking of using. If it passes air freely (like a microphone windscreen), then you can use it. If you can't, then it's closed-cell foam, and it won't work correctly.

    Fiberfill is generally easier to work with than glass or eggcrate foam. Don't forget to glue or staple here and there, so it stays put.
     
  8. negativefx

    negativefx complete hack Gold Supporting Member

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    Since I'm not sure if it's going to be an improvement (not to discredit anyone's opinions I've seen on the issue... just not sure for me), I want to be able to remove it easily if I don't like it. I was thinking of using some spray adhesive to attach velcro to the material and then velcro it to the cab. There won't be 100% surface attachment in that case though. Any concern? I'll go huff some foam and if not I'll go get a mattress pad.
     
  9. will33

    will33

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    The difference would be smoother midrange and a less boxy or boomy sound. You may percieve it to be slightly less loud after the lining, but what it's really doing is smoothing off peaks and dips in the response.

    All speakers should have some amount of damping, at least on the back wall. You can however experiment with more or less on the other surfaces for slighter changes in tone. Don't put any lining where it could get in the way of the port opening inside the cab. Also don't put any over any crossovers or circuit boards that may be in there as those need to dissipate heat.
     
  10. wcriley

    wcriley

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    Why bother with the Velcro?
    Just use the spray adhesive. You'll still be able to remove the damping material later, if you want.
     
  11. negativefx

    negativefx complete hack Gold Supporting Member

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    Understood. Any comment on not having 100% attachment of the surfaces? I guess it would be similar to stapling.
     
  12. WingKL

    WingKL

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    May 12, 2007
    You may also find substantial improvement in tone if your cab is not already cross braced and you add it.
     
  13. BassmanPaul

    BassmanPaul Gold Supporting Member

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    Glue i would agree with Steve, but not staples. They can easily vibrate loose, I found this out the hard way :( , and get caught in the driver(s) magnetic field.
     
  14. will33

    will33

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    Any of this lining is really lightweight stuff. You don't have to smear the whole thing full of glue or use a ton of staples...doesn't take that much to hold it up.

    I've used staples in all mine and never had a problem....not saying it couldn't happen though.
     
  15. negativefx

    negativefx complete hack Gold Supporting Member

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    I think I'll try staples and if it sounds good, I'll go back through with glue. The egg crate I had isn't closed cell but it is around 3.5 inches thick so I'm going to pass on it. I got a roll of Morning Glory High Loft Batting from gov-mart for $8. I'm going to do up my 410 as well if the 115 sounds better.

    Thanks for all the tips everyone... much appreciated.
     
  16. steve_rolfeca

    steve_rolfeca Gold Supporting Member

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    So how did it sound lined vs unlined?

    My experience has been that it made a positive difference to the mids on cabs that were unusually shallow front-to-back, but less so on others.
     

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