My SVS wasn't bottoming, it was jumping!

Discussion in 'Archived Threads 2001-2004' started by Lanny Hoff, Mar 23, 2002.

  1. Lanny Hoff

    Lanny Hoff Stunt Coordinator

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    Since I got my 16-46+ about a month ago, I've been happy with it, but I was surprised how easily it bottomed out. Seems like whenever we got the joint jumping, it was running out of steam.

    Well, it turns out that the joint was jumping-literally!

    What I thought was a bottoming subwoofer turns out to be a subwoofer that was jumping straight up and down, and as it clattered against the floor, it sounded like it was bottoming out.

    I slipped a piece of carpet padding under it, and now it sounds beautiful! Louder, deeper and better. Of course, I'm not saying the carpet pad made the sub sound better, it just plays a lot louder before it sound stressed out.

    By the way, the movie Joy Ride has some wonderful low-end. It's a really well done sound design.
     
  2. Dave Schofield

    Dave Schofield Second Unit

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    Not to be the pessimist, but is this even possible? Can a 16-46, which probably clocks in at 50+ lbs develop enough momentum in its driver to lift itself off the ground?

    Rattle...maybe, shake...maybe, jump...no
     
  3. Lanny Hoff

    Lanny Hoff Stunt Coordinator

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    hy·per·bo·le n.

    A figure of speech in which exaggeration is used for emphasis or effect, as in I could sleep for a year or This book weighs a ton, or my subwoofer is jumping around.

    OK. I may not have been "jumping around", but it certainly was rattling (what is a rattle but little, tiny jumps?). And now it's not, which i s great news for me.

    I thought perhaps this "leaping subwoofer" condition, which was quite loud and very distracting, may have been an issue for others as well.
     
  4. Dave Schofield

    Dave Schofield Second Unit

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    Sorry, perhaps that came across too negatively. What kind of floor do you have in your HT? I'm moving to an apartment with hardwood floors and I'm worried about rattle. I thought of picking up a few "treadmill mats" that you'll see at any sporting goods store (a high density rubber) to combat this. I would think that carpet pads would absorb a good deal of the energy of a downfiring sub... Thoughts?
     
  5. Brian Owens's BPD1803 sonosub will jump 1" off of the floor!..He is going to be adding a heavy base plate soon=) He just had legs before
     
  6. Lanny Hoff

    Lanny Hoff Stunt Coordinator

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    The carpet pad doesn't absorb any sound at all. It just sits between the base of the sub and floor and acts as a simple buffer. The sub is very stable on top of it, and there is absolutely no loss of sound. Think of it as sitting on top of carpet-lots of people do that with no ill effects

    I have vinyl tile flooring, but the problem would be the same with hardwood, so give it some thought if that's what you are going to do.

    I can believe that a sub can actually jump. Why not?
     
  7. Walt N

    Walt N Second Unit

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    I tried my 16-46's spiked through the carpet and padding at first, (do they even come with spikes anymore?) and they tap danced on the concrete subfloor like Mexican jumping beans. When you consider that the mass of moving parts is rather light being just the cone and the attached sleeve into the voice coil, it's quite impressive!
     
  8. Ian Fan

    Ian Fan Auditioning

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    "Supporting disk isolators" and vibration suppression pads (VSPs) are also an option. VSPs are designed for telescopes and are quite expensive, and while I don't think they would work well for subwoofers, I would like to know if anyone has ever tried doing that. (FTR, I've tried neither, but they might be the kind of thing you're looking for.)
     
  9. Bob_L

    Bob_L Supporting Actor

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    Sounds like a marketing opportunity:

    "SV Subwoofers: You will believe a sub can jump!"
     
  10. MarkO

    MarkO Second Unit

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    I cant see how a sub can jump 1 inch off the floor. Its not possible. The driver moves in and out when producing sound. In an ideal situation where the amp was clipping badly and the driver is violently pulled from full stop to full excursion is even far fetched. Dont the SVS subs have adjustable feet? If they do and they are adjusted evenly the sub shouldent vibrate.
     
  11. Joe Cole

    Joe Cole Second Unit

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    Well,
    On my wood floors my dual 16-46CS(old drivers) were jumping and even bent a spike. I put them on stone circles and it helped some. But during some movie, I forget which one of them fell off the circle and gave me a fright during a dramatic moment on screen.[​IMG]
    So far the new drivers are not doing this. The bass is tighter and quite noticably more powerful with no hint of bottoming out at high volumes.
    Yeah.[​IMG] [​IMG] [​IMG] [​IMG] [​IMG]
     
  12. Joe-T

    Joe-T Stunt Coordinator

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    Just be glad the SVSs are bottom-loaded subs. Imaging if they were a front-firing design. They would be hopping all over the place running into your furniture and walls [​IMG] .
     
  13. Ron Alcasid

    Ron Alcasid Stunt Coordinator

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    SVS has invented a fueless propulsion system! Someone call NASA! [​IMG]
     
  14. jeff lam

    jeff lam Screenwriter

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    MarkO,
    You don't know what a Blueprint 1803 is do you? I don't believe an SVS can jump 1" but if the enclosure isn't heavy enough and with enough power, you can get a blueprint 1803 to hop around a little I'm sure.
    Direct quote from Pat Morrissey of Blueprint Drivers:
     

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