Cleaner Bass By Accident from My PB12??

Discussion in 'Speakers & Subwoofers' started by WilliamG, Nov 29, 2003.

  1. WilliamG

    WilliamG Supporting Actor

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    In the haste of cleaning up the house for Thanksgiving Day company, my wife set seven LARGE books on top my JBL PB-12. When I demoed my system last night using Jurassic Park III something unusual happened. I went to the part where they're taking off in the plane (towards the beginning of the movie) and it crashes, breaks apart, etc. Then a dinosaur appears and the fun starts.[​IMG] Lots and lots of LOW bass. OK, here's the deal: NOTHING on the walls rattled. Everything sounded "tighter". Crisper, cleaner bass.
    I've had the NSP1's for a year and a half with absolutely no complaints. Then this 'accidental' occurance.
    Do I need to stuff my PB12 with polyfil? If so, with what kind and exactly how is it done?
     
  2. Tom Vodhanel

    Tom Vodhanel Cinematographer

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    Man, there's a lot of variables that can enter into the process here...

    1)the books could just have been resonanting a little...throwing off their own harmonics.

    2)the calibration levels may have changed? I can't imagine a scenario where just setting the books on the subwoofer will lower a certain frequency/output so much that all the pictures would suddenly stop rattling? Could she have move the subwoofer too?

    Tom V.
    SVS
     
  3. WilliamG

    WilliamG Supporting Actor

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    Tom,
    No, she didn't move it, but, come to think of it- I did. But only by as little as 6 inches. Along the same wall, though. It's hard for me to fathom a change that drastic, too. Well, we watched LOTR:TTT last night and nothing rattled. I guess I can do this by trial and error and move the books off the sub to see what happens! That may give me something more to go on.
     
  4. Ken Custodio

    Ken Custodio Second Unit

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    Maybe the extra weight just braced the cabinet a little more to help keep it from flexing as much??

    I had a JBL sub and it did have a good amount of polyfill in it but it had bunched up to one side, I guess during shipping. Just unscrew the front screws and carefully remove the speaker, watch out for the the speaker wire. Then either even out the polyfill or add more, you can get it at any craft store, its what they use to stuff dolls and pillows. Its pretty cheap.

    Ken
     
  5. John_Bilbrey

    John_Bilbrey Stunt Coordinator

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    The PB12 is bottom firing. It's pretty tight in there, too. I had to take apart the thing to retrieve a small screwdriver the least one of the bunch had hid in there for me. In doing so I found the long-lost Dish remote! Anyway, I don't know that the stuffing will help with this one. Perhaps just the placement will. It makes a big difference in my sound.
     

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