Is speaker blown if it is "scratchy" when you push on cone?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by kingsxman, Aug 29, 2005.


  1. kingsxman

    kingsxman Silver Supporting Member

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    One of my new Carvins (sale) didnt seem to make my "burn in" period. It is scratchy when I push in on the cone (back and forth).
    I heard a "break up/crackling/floppy" noise once from the speaker...but didnt hear it again.

    FYI, these seem like ok speakers. Very dark sounding. I dont think they are too much like a V30 however. They're thier own sound.
     
  2. Reeek

    Reeek Member

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    Well, in the best case, it's plain old cone rub and that alone makes it a bad speaker.
     
  3. Scumback Speakers

    Scumback Speakers Gold Supporting Member

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    Yep, that's voice coil rub, alright. Felt enough of 'em to know. How were you "breaking in" these speakers?

    To clarify my answer, while the speaker now has voice coil rub (and will sound like A$$), it's not technically "blown" which is when it has no ohm reading on a multimeter. But it will eventually blow from the heat caused by the voice coil rub, since the extra heat will overheat the wires running to the coil, and then it will read "O" or "open" (no reading) on a multimeter.

    Take it out, get it reconed, or replaced, cuz it's going to sound bad (and get worse) from here on out...sorry!
     
  4. kingsxman

    kingsxman Silver Supporting Member

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    Break in was something that someone here recommended in another Carvin thread (amps and cabs forum). It was something suggested by Ted WEbber.
    Spray fabric soften on the cone (keeping the dust cap dry). Wipe off...repeat. Then pump rap music throgh the speaker for a few hours. Supposedly this works. I hadnt tried it before...but since these speakers are going in a cab that doesnt get used a ton...it will take a YEAR to get them broken in otherwise. I wish I'd have tested it better before starting the break in period. It may have had cone rub from the start.

    In any event, they're still in thier initial 10 days. I hope I dont have issues returning if the smell a little..well...."april fresh"!
     
  5. aeolian

    aeolian Member

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    Don't know about the fabric softener, but getting a paper cone wet is a good way to warp it. A warped cone will twist the voice coil around some way, and there you go. Voice coil rub.

    I can see, lightly applying something (very evenly) to the surround, but not the whole cone.
     
  6. kingsxman

    kingsxman Silver Supporting Member

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  7. KCblues

    KCblues Member

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    I think the failure mode caused by voice coil rub is that the coil wire gets rubbed and worn until it breaks, and then you have an open coil.

    In any event, I agree the speaker is already "toast"
     

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