New Sonotube Material

Discussion in 'Archived Threads 2001-2004' started by Fred Seger, Jun 18, 2001.

  1. Fred Seger

    Fred Seger Stunt Coordinator

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    A customer of mine came in today with a piece of PVC pipe that was 16" in diameter. Maybe some of you have seen PVC this big, but I never have. The walls were 1/2" thick and he said that it also came in larger sizes. Price was about $10/ft.
    Any reason why this wouldn't work great as a sub tube. It would be slightly heavier than a sonotube but finishing would be easier - the smooth surface would just have to be painted. I don't know what the resonant freqency of this stuff is though.
    If he has some sections left over form the job I think I might try making a sub or two.
     
  2. Jin E

    Jin E Second Unit

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    I'm no expert... but I would definitly worry about resonance. Take a peice and hit it with your nuckles. What type of sound does it make? I imagine you would want a dull thud. Any echoing down the tube I would guess would be bad. I would also guess it would be hard to dampen one of these things. I would love to get a piece of that and give it a try. I've been itching to build a 16-18" diameter Shiva similar to my world's cheapest $81 sono-sub (as seen in my Sig).
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    -Jin
    My Theater
     
  3. Andrew Pratt

    Andrew Pratt Producer

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    actually I'd think it would do very well. Once you get the end caps on it should stiffen the tube quite a bit. just add in some fiberglass around the outside and its worth a try. The added weight might help it a bit too [​IMG]
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    http://www.attcanada.ca/~itisi
     
  4. Greg Monfort

    Greg Monfort Supporting Actor

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    Actually, you want it to ring like a ten penny nail struck with a ballpeen hammer. [​IMG] This ensures that the driver can't excite its resonance modes. I do recommend that at least 1/2 the wall gets lined with some acoustic damping material to quell any spurious HF resonances. Mostly though, you want to make sure there's no standing wave pipe resonances along its length.
    BTW, some years ago I saw 36" PVC drain pipe being installed under a parking deck construction, but don't know if it's still available. I imagine that pricing would be pretty steep for DIY.
    GM
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    Loud is beautiful, if it's clean
     
  5. John Morris

    John Morris Guest

    I wonder if this is similar to the new tubing that SVS is using in their new Ultra subs. Here is how SVS describes it:
     
  6. Julian Data

    Julian Data Second Unit

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    I recall ChrisA used some 9" black ports from some company. Cubic something..
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  7. Jack Gilvey

    Jack Gilvey Producer

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  8. Julian Data

    Julian Data Second Unit

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    That's the "earl". [​IMG]
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  9. John Morris

    John Morris Guest

    Hi Jack:
    Hmmmm... I am just wondering. Are you the new 3rd partner in SVS?
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    Take Care,
    merc
     
  10. Brandon B

    Brandon B Second Unit

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    16" PVC retails for about $25/ft, 18" $35/ft. You can probably get it cheaper, and 4 foot or maybe even 6 foot pieces might be considered "scraps" for where this stuff is generally used and available even cheaper.
    But as mentioned above, while stronger than sonotube, it is not acoustically dead by any standard, and due to its plastic nature, is extremely hard to deaden. And most glues that stick to wood do not stick to it. Some will, like methacrylates and epoxies. You can also weld other PVC pieces to it, so you could actually make your caps PVC and then weld in a port.
    My reason for not using it would be, however, PVC gives off toxic fumes (chlorine gas) when burned, and if you should suffer a housefire I'd hate to have a family killed by my sub.
    BB
     
  11. Jack Gilvey

    Jack Gilvey Producer

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  12. Greg Monfort

    Greg Monfort Supporting Actor

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    >I recall ChrisA used some 9" black ports from some company. Cubic something..
    ====
    IIRC, they are black only because he painted them.
    GM
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    Loud is beautiful, if it's clean
     
  13. John Morris

    John Morris Guest

     
  14. Jack Gilvey

    Jack Gilvey Producer

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    I know, John, hence my smart-ass alternate answer. [​IMG]
    (I wouldn't call my experience vast, though, when compared to the others who post here, some way out of my league. I'm just very interested in it. [​IMG] )
     

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