why adire uses foam surrounds?

Discussion in 'Archived Threads 2001-2004' started by Ryan T, Oct 6, 2001.

  1. Ryan T

    Ryan T Second Unit

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    Hi, I’m wondering why adire audio uses foam surrounds instead of rubber, It is my understanding that rubber is much better because it is more durable and more flexible, is this correct or not?
    Ryan
     
  2. NathanP

    NathanP Supporting Actor

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    Good Question...
    [​IMG]
     
  3. Rich Kraus

    Rich Kraus Stunt Coordinator

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  4. Rick Chwiendacz

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    Rubber is more durable, but in pretty much every other aspect, foam is superior.
    1) Foam is lighter, which reduces your moving mass and increases efficency.
    2) Foam is much better at terminating the edge of the cone, to reduce the amplitude of any resonances that exist.
    3) It's easier to make a high-excursion surround out of foam. Foam also tends to be more linear at high excursions than rubber. Rubber surrounds tend to have more variance in their compliance over their usable excursion. Rubber surrounds are more commonly used in situations where ultra-high excursion isn't needed.
    4) Foam is also much better at locating the cone (keeping it centered) than rubber is. I have heard that some designs using rubber surrounds had to have larger tolerances in their magnetic gap, which reduces the motor strength, because the rubber surrounds weren't able to keep things aligned at high-excursions well enough.
    How're those for some good reasons? =)
    I'm sure Dan Wiggins will step in and set the record straight as to the exact reason why the boys at Adire decided to go with foam. Needless to say, I think that was a very good decision on their part.
    - Rick
     
  5. Dan Wesnor

    Dan Wesnor Second Unit

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    I'm willing to be "cheaper" is one of the reasons. One of the stated design goals of the Shiva was low cost.
     
  6. James W. Johnson

    James W. Johnson Screenwriter

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    I doubt cost is even a factor in using foam surrounds, I bet its just a design preference.
     
  7. Rick Chwiendacz

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    I agree 100% that cost isn't much of an issue. Many of the ultra-low end car subwoofers use rubber surrounds - I have a couple of 10's I bought with rubber surrounds for $18cdn each!
    If the entire driver is $18cdn, including retail markup, shipping from overseas, and assembly costs, I can guarantee you the rubber surround didn't cost all that much.
    - Rick
     
  8. Ryan T

    Ryan T Second Unit

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    Yeah that makes since about adire using foam surrounds instead of rubber for the shiva. I guess the only thing I don’t understand is why I see so many new speakers with rubber surrounds for their woofers and midranges is there any specific reason for this?
    Ryan
    [Edited last by Ryan T on October 07, 2001 at 03:55 PM]
     
  9. Rich Kraus

    Rich Kraus Stunt Coordinator

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    ryan, i believe its because J6P percives rubber to be better (or a better value?). its all about sales to the masses once you get away from DIY.
    ------------------
    'Till next time,
    Rich (the kite guy)
    My DIY audio page!
    Use your ashtray please, dont throw um on the street. thanks [​IMG]
     

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