Subwoofer rattle...bottoming out?

Discussion in 'Speakers & Subwoofers' started by Joe Wong, Jan 25, 2004.

  1. Joe Wong

    Joe Wong Second Unit

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    Hi all,

    I have a dual SVS 20-39CS+ setup, with one in each corner at the front of my HT (see http://forum.av123.com/photopost/sho...er=374&thumb=1 for some pix).

    This afternoon I put on the re-issued DTS Jurassic Park (with the massive LFE) just to have some fun. During the T-Rex attack scene, I can hear something rattling in the left sub. I have my LFE level at -3db, on my Outlaw 950 pre-amp, with a usual listening volume of -15db (though I only had it at -20db this afternoon).

    Could this be the sub bottoming out or is there something loose? If it is bottoming out, wouldn't both subs be bottoming? Also wondering if maybe I should move the left sub next to the right, to get the "stacked" effect.

    I've heard it rattle before, when playing Attack of the CLones, but I thought it was just bottoming and lowered the LFE level. But during JP, even at -24db master volume, the sub rattled.

    Any advice would be appreciated! (BTW, the bass on this DTS version is enormous.)

    Thanks!

    Joe
     
  2. Joe Wong

    Joe Wong Second Unit

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    Just as a follow-up, I did have both subs next to each other in an upstairs bedroom (in an earlier HT setup) that was probably of similar volume to the current HT room albeit different shaped. I think I recall I had the subs at about +3db (as is recommended during calibration) and don't think they ever rattled.

    Joe
     
  3. Edward J M

    Edward J M Cinematographer

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    Best to check with SVS tech support. If you never outright bottomed the woofer (that you know of), chances are it's OK.

    It could also be something in that area rattling that you are unaware of. I've lost count of the number of people who swore their sub was making noise and it turned out to be a loose piece of wood molding, or a potted plant nearby, or a drywall rattling against the stud, etc.

    Finally, swap the subs and see of the noise follows the sub.

    But do give tech support a buzz and see what they have to say - they are open 24/7 and you can expect a quick response.

    Regards,

    Ed
     
  4. ScottCarr

    ScottCarr Second Unit

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    I ran into a similar problem and it ended up beng the calibration.

    I was running too hot and the phase was significantly off.

    but still check with SVS.
     
  5. Joe Wong

    Joe Wong Second Unit

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    Thanks guys.

    Joe
     
  6. terence

    terence Supporting Actor

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    Hi Joe,

    I would defitnatly e-mail SVS on your issue. I have the 1st DTS JP dvd. What is the difference between the oringinal and the re-issued version?
     
  7. Joe Wong

    Joe Wong Second Unit

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    Hey Terence,

    The original DTS DVD of JP had a bass-deficient soundtrack, which is remedied by the re-issue. I believe Universal still operates an exchange program if you send your original to them.

    Cheers,

    Joe
     
  8. Mike_Skeway

    Mike_Skeway Second Unit

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    The sound of a sub bottoming out is like a slap or clack, not sure if this is what you heard or not so it is hard to say if it was that or not. But as others have said you may want to contact SVS.
     
  9. terence

    terence Supporting Actor

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    Thx Joe, and good luck.
     
  10. Lin Weiwen

    Lin Weiwen Stunt Coordinator

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    Edward is right. At one stage,whenever I was watching scenes with deep bass like Sauron's demise in FOTR or the opening ship sequence in Star Wars Ep1...I used to hear a slight rattling sound which seemed to emerge from the area around my subwoofer. After closer inspection, I realised that it was the old cabinet (which was placed beside my sub due to space constraints) from which those rattles were emanating from. I soon found out that by opening one of the cabinet's doors and leaving it ajar solves that 'rattle' issue. Now I can peacefully watch those intense scenes without any external noise. [​IMG]

    Nowadays...the only possible rattle I might hear is the neighbours coming over to 'rattle' my front gate. [​IMG]
     
  11. Doug_NHT

    Doug_NHT Stunt Coordinator

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    I had a clacking sound in on of my NHT sub2i subs but it only happened during Balins tomb or SWII during the beginning scene with the flyby of that silver ship. I could only get it to do this when I played a 20Hz test tone. I pushed on the driver and heard a slight crunchy rubbing sound. Turns out that the voice coil was burned. It took forever to find that but I guess I should have pushed on that driver first and saved myself some time.
     

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