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Ampeg B15 Cabinet damping ??

Discussion in 'Amps and Cabs [BG]' started by superfly, Feb 9, 2005.


  1. superfly

    superfly

    Aug 4, 2004
    Anyone here know what inside panels of a vintage Ampeg B15 cabinet are suppossed to be lined with damping material?

    Were all the surfaces inside lined? or just the back? or ?
     
  2. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    As I recall they used rigid fiberglas on at least the back, chances are it was insufficient. I'd redo it in user-friendly inch thick polyester batting (furniture upholstery), completely lining the cabinet, which would clean up the midrange considerably.
     
  3. superfly

    superfly

    Aug 4, 2004
    Is the batting material preferred over say 1/2" -1" thick flat surface foam? (like cushion or bedding foam) ? Or will the foam do the same thing?
    I ask because I have some foam lying around.
     
  4. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Foam is OK, especially if you already have it about. I use poly as it's cheaper and just as effective.
     
  5. superfly

    superfly

    Aug 4, 2004
    Line ALL the surfaces? speaker baffle too? (inside front)
     
  6. I know this is old, but I am very interested in this as well as it is next weekend's project for me.

    So poly? Where's the best place to source that? How thick? Every surface? back, sides and baffle?

    Thanks!
     
  7. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    The originals came with a back wall covered in fiberglass insulation, but the Heritage B-15's use a much more friendly foam padding of some sort. Only the back wall is covered. I've experimented with lining all the walls of the cab with foam and it makes no difference to the sound, so lining the back wall is sufficient to kill standing waves inside the cab.
     
  8. I suppose I can just experiment too. It's a '65-'66, and while I don't want to kill the original sound, it still has the original material in there.
     
  9. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    You could experiment but I'd just leave it. If Ampeg thought it could be improved by adding more padding, the Heritage B-15 would have more padding.
     
  10. True, but it's pretty ragged from years of road life, smoke, etc.
     
  11. stiles72

    stiles72

    Mar 20, 2009
    Albany IL
    When I restored my B15, the local uphostery shop gave me some yellow foam that is a little over 1" thick to use for lining the cab. I used it on the back wall and also on the floor since there were some rough spots that I wanted to conceal that weren't real pretty.


    [​IMG]
     
  12. Here's the inside of my old one...

    [​IMG]

    I was regluing the baffle - it was a bit loose and buzzing.