insulation as damping?

Discussion in 'Archived Threads 2001-2004' started by David Giesbrecht, Aug 16, 2001.

  1. David Giesbrecht

    David Giesbrecht Second Unit

    Joined:
    May 28, 2001
    Messages:
    306
    Likes Received:
    0
    Trophy Points:
    0
    Can you use standard insulation as damping for your sub, if so are their any disadvantages.
     
  2. Patrick Sun

    Patrick Sun Moderator
    Moderator

    Joined:
    Jun 30, 1999
    Messages:
    38,749
    Likes Received:
    480
    Trophy Points:
    9,110
    I wouldn't use the stuff in a vented sub, due to the fibers being sent through the port and into the air. No one needs their sub to make them itchy.
    For a sealed sub, I guess it'd be okay, but still not my first choice (pillow polyfill is good enough, and available at places like JoAnn's, Wal-Mart, etc).
    ------------------
    PatCave; HT Pix; Gear; DIY Mains; DIY CC; Sunosub I + II + III; DVDs; LDs
     
  3. Brian Bunge

    Brian Bunge Producer

    Joined:
    Sep 11, 2000
    Messages:
    3,716
    Likes Received:
    0
    Trophy Points:
    0
    Patrick,
    I've wondered about that myself, but it appears that SVS is using standard insulation from a picture I saw a while back. I know Chris Artman used it in his Black Hole subs.
    I also thought I heard somewhere that the fibers can be damaging to the speaker driver itself, but I don't know what the issues were exactly.
    Brian
    ------------------
     
  4. Greg Monfort

    Greg Monfort Supporting Actor

    Joined:
    May 30, 2000
    Messages:
    884
    Likes Received:
    0
    Trophy Points:
    0
    FWIW, in the good old days before the current crop of sub drivers became available, huge cabs (15+ft) were required to get 20Hz performance, and I lined them all either with R-19 fiberglass with the paper backing removed, or the backless version used to line large air ducts.
    After reading Pat's response, it made me curious enough to remove the cloth cover on a reflex vent that's been in place since I built it back in '69, and can't see any obvious FG particle residue.
    That said, if you use FG to stuff a reflex (which I don't recommend), it can literally be blown out the vent so a cloth cover is mandatory IMO. Or you can do as many have done with Aperiodic designs which is to hang a 'blanket' of FG from the top of the cab.
    WRT damaging the driver, I've loosely stapled a 'blanket' directly over the back of many drivers to lower their Q with no damage AFAIK. Indeed, this was the published standard for the final 'critically damping' of a reflex in the past.
    For smaller cab volumes where lining the walls with FG tend to overdamp them, I use 1/2" felt carpet padding.
    If handling it is a major issue for you, there's always Miraflex, which seems to work just as well, and in some cases more so since it's rated R-25.
    GM
    ------------------
    Loud is beautiful, if it's clean
     

Share This Page