Damping material for bookshelf monitors?

Discussion in 'Archived Threads 2001-2004' started by jeff lam, Dec 20, 2001.

  1. jeff lam

    jeff lam Screenwriter

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    I spent all last night assembling the GR research AV1's. There was no damping material in the kit so I need somehting good. Blackhole5 is too expensive. Are there any cheaper alternatives that work well like batting material or fiberglass insulation? Also, how much do you usually need? All interior walls? only back and sides?

    BTW, I fired them up last night without the damping material to get started breaking them in. Right from the start these babies started singing. I am very impressed with these speakers so far. They are very detailed and precise with tight defined bass and I know they will only get better as they loosen up a bit.

    I will post more reviews of these speakers and the MB1's after the new year.

    Thanks!
     
  2. Brian Bunge

    Brian Bunge Producer

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    Jeff,

    I think polyester batting should be fine but I'd ask Danny at GR about that. Since he designed the speakers he'd be the one to ask. If it requires batting but wasn't included then it doesn't exactly sound like a complete kit. At the very least they should include instructions as to what material to use and how much. But it's possible that they aren't supposed to have batting.

    Brian
     
  3. Hank Frankenberg

    Hank Frankenberg Cinematographer

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  4. jeff lam

    jeff lam Screenwriter

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    I asked Danny and he said:

     
  5. Brian Bunge

    Brian Bunge Producer

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    Jeff,
    I've heard of this method before in some Speaker Builder Magazine articles. But this is my question. Danny designed the speakers right? Well, he should be able to tell you exactly what (if anything) he uses in his speakers. You can't just say line all the walls with vinyl and then egg crate foam without nowing how it affects the entire system. If this is truly his official recommendation then I'd say run with it. But from the articles I've read, it is possible to overdo things when it comes to adding damping material.
    To me the whole point of buying kits is all of the guess work should be taken out of the equation. That's why I recommend the Emeralds to everyone. Every item needed to put together the speakers is included in the kit (excluding the cabinets of course). Every screw, every piece of batting and egg crate foam, every speaker connector, every wire, even piece gasket tape to seal the drivers. If you built (or had someone build) the cabinets ahead of time when the Emerald kit came there would be absolutely nothing else for you to buy to assemble the speakers. I guess that's the price you pay for convenience![​IMG]
    Hank,
    It being the week before Christmas things are rather slow and my lunch break has been at bit "extended" most of the week!
    Brian
     
  6. jeff lam

    jeff lam Screenwriter

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    Brian,

    I'm sure Danny uses blackhole 5 in all his enclosures. I would too except it's very expensive. He sells it for like $50. Supposedly there is nothing that can beat it.

    The kit was complete down to every screw except for the damping stuff. The kit could use better directions too though. If you are not experienced with components or speaker building you would probably be lost. I guess that goes for any speaker kit though.

    Brian, its too bad you live on the other side of the country, I would really like to meet you and talk about speaker stuff.
     
  7. Randy G

    Randy G Second Unit

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    Brian,
    You're such a whore...(inside joke)
    Just as a side note, that asphalt stuff appears to be the same as the sound barrier/anti-crack/moisture barrier stuff that I used for underneath my ceramic tile. It sells under the name of Protecto-Wrap and goes for about $1.25-1.50 a square foot. It's also 40mil thick, but I haven't bothered to translate that to inches...anybody? On a ruler, it looks pretty close to .03"....Ooops, that's only HALF as thick as the PartsExpress stuff.
     
  8. Brian Bunge

    Brian Bunge Producer

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    Jeff,

    Yeah that Blackhole stuff does seem a bit expensive, especially for the price range that the speakers are in.

    I'd love to be able to meet you too! But you know it's dangerous when to DeVry guys get together!

    Brian
     
  9. Hank Frankenberg

    Hank Frankenberg Cinematographer

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    And if this Texas DeVry guy were added, it could reach critical mass! So Randy, tell me about the real Brian before I get too involved with him in designing a B****-beater.

    The material from Parts Express seems to me to be what some companies repackage and sell for a tremendous profit to the car audio fanatics for dampening/deadining sheet metal door panels, floorboards and trunks.

    The reference to "overdoing" the dampening applies to the polyester/fiberglass/eggcrate foam issue. That material is used to "stuff" speaker cabinets to absorb airborne sound energy so it doesn't color the driver cones' vibrations, and of course it's also used to simulate a larger cabinet as "seen" by the drivers for tuning purposes. The purpose of the thin, viscoelastic material applied to the inside cabinet walls is to dampen/absorb wall vibrations induced by sound waves inside the cabinet as well as driver mounting physically-transmitted vibrations.

    Maybe ThomasW or other pros can jump in and correct/clarify my statements.

    With that, I'm headed to happy hour...
     
  10. Randy G

    Randy G Second Unit

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    Watch out for that Brian guy...I hear that he's into some weird stuff involving woofer ports. And don't forget his last name.... tells the hole tail...er, whole tale.
    he he he he he
     
  11. Brian Bunge

    Brian Bunge Producer

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    Hank,
    I don't think correspondence courses count![​IMG] Unless you're in debt for over $20K worth of student loans (over $40K in my case) you're not truly a "DeVry Guy"!
    The overstuffing comment came from a Speaker Builder article in which the author built an MTM satellite/bass cabinet design. He used constrained layers between the MDF and layers of 2 or 3 different materials (including floor tiles and eggcrate foam) in the subwoofer enclosures. Through response testing he found that he'd basically overstuffed the enclosures and actually took away from the effective internal volume instead of adding to it.
    Randy,
    I am the Great Bunge Julio! I need TP for my Bunge Hole!
    Brian
     

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