Dumb speaker cab question.. Acoustic 104

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by nrandall85, Feb 8, 2012.

  1. nrandall85

    nrandall85 Member

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    I picked up an Acoustic 104 6x10 cab and 150 head yesterday. I'm trying to check all the speakers- seems like one in there is a little messed up and I was to visually inspect them, check with a multimeter, see if I can repair etc.

    Problem is, I've never owned a speaker cabinet in my life and I don't know how to take the darn thing apart. There's six screws on the baffle, but when I take those off it's not like the whole thing slides nicely out. I don't want to mangle all the cloth, yank the wire to the input jack, etc.

    Any suggestions?

    While I'm at it, the problem with the speaker is only on certain notes high up the neck (it's either F or F# on the guitar I'm testing with at the moment.) Sounds like it's distorted, or being played with a kazoo through a DS-1, or something along those lines. Is that cone cry? Something else?
     
  2. corn husk bag

    corn husk bag Silver Supporting Member

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    Send photos of (inside and out) it so we can see it then some one may be able to tell you how to get the thing apart.

    Kind Regards,
    Steve
     
  3. nrandall85

    nrandall85 Member

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    Here we go:

    No screws on the back, just the six on the front panel with the white edging that looks like it may not come off clean if I mess with it.

    I tested the ohms just using the speaker cable and got 3.9 if that helps with the speaker diagnosis.

    [​IMG]


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  4. nrandall85

    nrandall85 Member

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    I gave it a little more play tonight. It's producing kazoo-like distortion out of what sounds like only one speaker when I play F# at the 14th fret on the high E string. Out of curiosity, I ran my Foxrox Octron through it on the octave up setting and got the same result- on a lot more notes (too many to write down.)

    I'm bringing the whole cab in to a local speaker repair person tomorrow- I'm just nervous about the diagnosis since these speakers are so uncommon.

    Do these symptoms sound familiar to anyone? The amp and cab sound absolutely fantastic, so I'm hoping they can be made gig-worthy.

    Edit- I'm starting to think these may not be dumb questions....
     
  5. nrandall85

    nrandall85 Member

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    So far my research is pointing to cone cry. As far as solutions go, I've found:

    Rotate the speaker 180 degrees, the theory that the weight of the magnet can in time warp the speaker housing.

    Retention the speaker mounting screws. If over tightened, the speaker can exhibit the symptoms I'm describing.

    Add doping- sometimes works, sometimes does not.

    Repair any rips or tears in the speaker cone.

    Have the speaker reconed.

    Replace the speaker with a 16 ohm, dropping the load of the cabinet to slightly less than 4 ohms, but still close enough as to not cause damage to the amp.

    Anybody?
     
  6. OrganicTimbre

    OrganicTimbre Member

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    I think one or more of the speakers are probably shot, nothing unusual. Just a guess, looking at the thing and its advanced age, I'm thinking voice coil rub. Unless you love the speakers, I'd just replace it.
     
  7. nrandall85

    nrandall85 Member

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    Shot as in unable to be reconed/repaired? They're old Alnico Eminence's rated 24 ohms that sound (aside from issue) fantastic. Finding a suitable replacement (with aluminum dust cap) would take months.....
     
  8. OrganicTimbre

    OrganicTimbre Member

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    Not doubting you, but how do you know the impedance of the speakers?
     
  9. nrandall85

    nrandall85 Member

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    I found the original manual online.
     
  10. OrganicTimbre

    OrganicTimbre Member

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    My guess, and I have absolutely no way of knowing, is that you'll either have to recone the speaker or replace it. Once a speaker is damaged, it's damaged for good. I doubt that the frame is warped, though it's possible. If the frame is damaged, you will have to replace it.
     
  11. nrandall85

    nrandall85 Member

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    I brought the whole cab in to get looked at today. I'll post back once I know what it turned out to be.
     

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