Distortion free bass?

Discussion in 'Home Theater Projects' started by James W. Johnson, Aug 20, 2004.

  1. James W. Johnson

    James W. Johnson Screenwriter

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  2. Mary M S

    Mary M S Screenwriter

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    Reminds me of something my son told me this week. Have no idea if the salesperson was telling the truth.
    He was in “Car Toys” looking at subwoofers and noticed two holes lined up about ¼” apart in the cone of JL W7 on display. He commented to the Sales person. “Looks like you had some vandalism” the salesperson replied; No, - the unit was running a demo and a kid placed two rigid fingers against it to feel the cone excursion, just as the demo material hit a high pressure note. He said it broke both fingers.

    Don’t know if this is possible but your download reminded me of it

    will promptly pull over to let you out [​IMG]
     
  3. Owen Bartley

    Owen Bartley Second Unit

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    Holy crap, that poor sub. [​IMG]
     
  4. Chris Brock

    Chris Brock Second Unit

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    for real. that is an awesome driver and it is totally destroyed. What the heck happend to it though? i have never seen a driver behave that way.
     
  5. Cam McFarland

    Cam McFarland Supporting Actor

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    Dang.....I cant view it......[​IMG]
     
  6. Dennis Gardner

    Dennis Gardner Stunt Coordinator

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    Thats a 60 hz AC signal put through it by plugging it into a wall socket. I've seen speakers blow across a room when this is done.
     
  7. ThomasW

    ThomasW Cinematographer

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  8. Chris Brock

    Chris Brock Second Unit

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    hmmm that driver should have taken that like a champ though. We are "only" talking about 3000 - 4000wrms. I personally ran one of those exact drivers in some car audio SPl competitions with four 2kw+ amps. So basically over 8000wrms total. im not saying i could have cruised around town for an hour playing a test tone at max volume but it was obvious the driver would not have done what that driver did haha.


    my vote goes that the spider tore and there was a complete loss of cone control?
     
  9. Andrew S-

    Andrew S- Stunt Coordinator

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    Thats too much excursion for it to be the wall socket. Not unless he has like a 100hz tuning.

    Nice vid though.
     
  10. Scott Simonian

    Scott Simonian Screenwriter

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    [​IMG] Yikes! Is that what happens to a XBL^2 based woofer when it goes past its Xmech?
     
  11. Andrew S-

    Andrew S- Stunt Coordinator

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    After closer look it looked to be caused my the camera's frame rate and i ended up finding a thread on sounddomain's forums talking about it and thats all thats going on.
     
  12. Brian Tatnall

    Brian Tatnall Stunt Coordinator

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    Looks like the triple joint came loose, but the guy says the sub still plays fine.
     
  13. Seth_L

    Seth_L Screenwriter

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    That's why you don't use a digital still camera to shoot videos. You will get exactly what you see there.
     
  14. James W. Johnson

    James W. Johnson Screenwriter

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    So its basically an illusion then? Wow , I had no idea a camera could distort something that much.
     
  15. Seth_L

    Seth_L Screenwriter

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    I'm pretty sure it's an illusion. I've seen similar videos of other woofers taking by digital still cameras that look the same (where the cone appears to be moving in and out at an angle).

    I think it has something to do with the way the CCD/CMOS chip is scanned.

    However, the visual distortions seem a bit extreme to only be from the camera. However, it's really hard to say. If the owner says it plays fine... who knows...
     
  16. Yousaf

    Yousaf Second Unit

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    Heh when I saw that video I figured pretty quickly that it was the camera doing it...by the way, that's called "aliasing". [​IMG]
     
  17. Seth_L

    Seth_L Screenwriter

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    That wouldn't be aliasing.

    That would be the result of the cone moving while the imager is being scanned.

    You can see a similar effect with the shutter in most SLRs when they move a slit across the film plane.
     

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