Help! Subwoofer is crackling.

Discussion in 'Archived Threads 2001-2004' started by Allen Longcor, Sep 5, 2002.

  1. Allen Longcor

    Allen Longcor Supporting Actor

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    That's the best way I can describe it. Ok I first noticed this when watching LOTR. I had watched it a couple times previously with no problems. So I am watching the last hour of it at lower levels than I have listened to it at when I notice a sort of crackling noise. Like something is garbled in the bass. I figure something is rattling so I don't worry about it. I'm watch Blade 2 last night at low levels and it's doing the same thing. It's not every bass scene, just some. In fact the low bass still plays clean but the higher bass makes crackling or popping sounds. Does anyone know what the problem could be? I'm guessing that it has something to do with the driver. I have a custom built sub from acoustic-visions with an Adire Shiva driver. Any help is appreciated and I would be happy to provide more info if I can.

    edit: I ran the LFE frequency sweep from Avia to make sure that it was the subwoofer that was the problem. It was never completely consistent in the distortion on the upper bass, but the low bass never distorted or crackled. Sorry for the lack of technical terms.
     
  2. Kyle Richardson

    Kyle Richardson Screenwriter

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    Thats odd that it only does it on upper bass when the driver is moving the least amount (except at the tuning point)?

    Try CAREFULLY pushing the driver inward on the center of the driver's dustcap. Make sure you push straight back. Do you hear a scratching sound? If so then the driver is more than likely "blown" since the voice coil is deformed. If not, then try taking the driver out of the enclosure and making sure all wires are still hooked up and nothing is rattling in the sub enclosure or driver itself.
    If everything looks in order then you should test it with a different power source to rule out the amplifier. Try testing it with another amp if you have one laying around. If not, and IF YOUR RECEIVER IS RATED TO 4 OHM then you could always try using one channel from it. If you use a lower wattage amp then don't push it as hard as you're used to. Try the same demo material to see if it still presents the same problems.

    If everyting points to the driver as being at fault then contact me to arrange for shipment back to Adire for further testing.

    PS. LOTR and BLADE 2 are recorded quite loud and have massive bass. If you are listening to them at the same volume level on your receiver as most other movies then you may just be pushing the driver too hard. There have been quite a few posts about these two movies recently.
     
  3. Ryan Peddle

    Ryan Peddle Second Unit

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    Two words.....VOICE COIL.

    My Paradigm PW2200 had the same problem. I took it into my dealer and they replaced the driver.

    There is no easy way to fix it. And it will only get worse.
     
  4. John F. Palacio

    John F. Palacio Supporting Actor

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    I wonder if somebody responsible for the mastering of LOTR has stock in a subwoofer manufacturer.

    It seems that more subs have been destroyed by this movie than by all others put together.

    IMHO I don't think that the bass was that low, it is just that the whole track was recorded "hot" and those that set their proc at a certain # are in for a surprise. I know I was. I mean even the dialog was way too loud!
     
  5. Allen Longcor

    Allen Longcor Supporting Actor

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    Well after some advice my problem "seems" to be fixed. the very helpful Kyle sent me an email taht is also posted above. I actually pressed too hard on the dust cap and bent it in a little bit. I didn't hear or feel any scratching. I power it back up and it's working fine again. So it just has an indentation on the driver but seems to work fine. This weekend when I put it through its paces I'll know for sure. [​IMG]
     
  6. Kyle Richardson

    Kyle Richardson Screenwriter

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  7. Allen Longcor

    Allen Longcor Supporting Actor

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    Well it is downward firing so the only one who would notice is a mouse. [​IMG]
     

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