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Auralex Gramma For Removing Excess Rumbling?

Discussion in 'Amps and Cabs [BG]' started by PolkaHero, Sep 2, 2002.


  1. PolkaHero

    PolkaHero Supporting Member

    Jan 5, 2002
    Michigan
    My bandmate discovered this product when he was at Sweetwater in Indiana. It is a board with acoustical foam underneath that you set your speaker cabinet on.

    He A/B'd a bass amp with and without the Gramma and said the difference in sound was rather remarkable. He said it removes the "boominess" one confronts with hollow stages and certain halls without taking away from the overall lows.

    Anybody here use or have tried this product? Is it worth the $50?
     
  2. Couldn't you just build something like that for about 20 bucks?
     
  3. BFunk

    BFunk Supporting Member

    I use a pair of these under my 8x10 Megaliath. They are excellent. They really do a great job tightening up the bottom end and making everything sound clearer in the low-mids. This is especially useful if you find yourself on a stage that is essentially a big, hollow box.

    Sure, you could built something like this. But don't think for a second that this is some kind of cheap mattress foam. This stuff is made of special high density material specifically designed for this purpose. Aurelux is a leader in studio sound isolation systems.

    To me it was definitely worth the $50 a pop.

    You can also get them at www.zzounds.com.
     
  4. Tsal

    Tsal

    Jan 28, 2000
    Finland, EU
    It's no 'miracle product', though. How it works is it isolates the cab from the floor preventing the floor help to bounce the lows out better. On some stages, it's probably very handy preventing muddy tone.
     
  5. RevGroove

    RevGroove Commercial User

    Jul 21, 2002
    Burlington ON Canada
    Manager, Account Services: Long & McQuade Ltd. (Burlington); MTD Kingston Basses International Emerging Artist; Bartolini Electronics Emerging Artist
    I posted about 3 weeks ago asking if anyone knew anything about the GRAMMA. There are only 3 AURALEX dealers in all of Canada, but luckily 2 of them are in the GTA (Greater Toronto Area). I had to order them by the case though, but a buddy/co-worker of mine wanted to try three of them, so I lucked out! The price is really not that bad, and if it does what everyone says it does, including reducing room resonance/rattling, then it's perfect for my needs!!!:D :D :D
     
  6. I just built myself an isolation platform.

    3/4 high grade plywood
    Black Paint or Carpet
    Big Rubber Feet (2 5/8" and FAT)

    Cost = next to nothing.

    Option: Removeable 3" wheels (that clear the Feet) to do double duty.
     
  7. ganttbos

    ganttbos The Professor Supporting Member

    Dec 18, 2001
    New Orleans area
    I built one too! 3/4" plywood with outdoor carpet glued on top (you can find small scraps at a carpet place - a guy gave me a large piece gratis). For the foam on the underside I bought a $10 sleeping pad at Walmart - one of those roll-up camping pads about 5/8" thick - very dense foam. I glued one thickness onto the whole bottom area of the plywood using Weldwood contact cement (the kind you can brush on from a can). Then I laminated "feet" for the four corners and one for the center (about 5 X 5") using two additional cut thicknesses of the pad - again glued with contact cement.
    The improvement in sound is really good on hollow wooden stages as mentioned above, but you can tell the difference in an A/B comparison on nearly any floor, even a concrete slab in my workshop. The caster idea is cool - I didn't do that.
    G
     
  8. PolkaHero

    PolkaHero Supporting Member

    Jan 5, 2002
    Michigan
    You get pretty good results from your homemade job, Donne?
     
  9. You bet.
     
  10. PolkaHero

    PolkaHero Supporting Member

    Jan 5, 2002
    Michigan
    Donne, Where did you find those rubber feet? I looked all over Stewmac and AllParts and couldn't find anything.:(
     
  11. PolkaHero

    PolkaHero Supporting Member

    Jan 5, 2002
    Michigan
    I'm thinking of using Donne's idea but also buying two 1'x1' sections of Auralex's Studiofoam(for a measly $6) and gluing those to the bottom of the board, then using a staple gun for carpet on the top.

    The last wedding I played had a huge wooden stage. I had the bass control on my amp rolled off ALL THE WAY and the bass response was still more than the P.A. was producing!
     
  12. I got mine at the local Hardware Store.

    When you start getting large they are known as
    "Bumpers" and are manufactured for Trucks, Trailers, Cabinets, and other industrial app.'s.

    PolkaHero's Idea is Excellent:

     
  13. jokerjkny

    jokerjkny

    Jan 19, 2002
    NY / NJ / PA
    YowZa!

    this could be just what the doctor ordered! a friend of mine has been having huge problems with boom, and he's using a pair of 2x10's.

    nice. :D
     
  14. Fuzzbass

    Fuzzbass P5 with overdrive Supporting Member

    Excellent point. On some stages it may improve tone, on other stages it might degrade tone (sometimes it's better for the cab to couple w/the floor). But heck, it wouldn't be a huge inconvenience to carry one of those things around.
     
  15. RevGroove

    RevGroove Commercial User

    Jul 21, 2002
    Burlington ON Canada
    Manager, Account Services: Long & McQuade Ltd. (Burlington); MTD Kingston Basses International Emerging Artist; Bartolini Electronics Emerging Artist
    Wow, picked mine up today, and it ROCKS! Excellent improvement in tonal quality!!! I'll be jamming tomorrow night, so we'll see if it passes the test in a group setting...:D
     
  16. PolkaHero

    PolkaHero Supporting Member

    Jan 5, 2002
    Michigan
    Let us know how it performs on your gig, Groove M.D. I've given up on my project of building my own simply because I can't find the rubber feet to go on the bottom. I'll probably buy the real thing but just want to be sure I'm not wasting $50.
     
  17. RevGroove

    RevGroove Commercial User

    Jul 21, 2002
    Burlington ON Canada
    Manager, Account Services: Long & McQuade Ltd. (Burlington); MTD Kingston Basses International Emerging Artist; Bartolini Electronics Emerging Artist
    yo Polka, go get one! This thing definitely lives up to the hype! There's a door that usually rattles where we play when I hit certain notes...with the GRAMMA under my rig, we didn't hear it even once!!!:D
     
  18. PolkaHero

    PolkaHero Supporting Member

    Jan 5, 2002
    Michigan
    Thanks for the report, Doc! I'm playing a bunch of weddings in the near future in various halls, and this might make a big difference in the acoustical problems that I'll face.:)