celestion blackback speakers

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by majicmerlin4, Apr 20, 2016.

  1. majicmerlin4

    majicmerlin4 Silver Supporting Member

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    today I purchased a old Mojotone 4x12 cab off the local c/list. The speakers look like 70's blackbacks.
    G12m 25w 8ohm 55hz. 444 cone and t1871 stamped. I have not had time to really test drive them yet but they did sound nice and look in mint condition.
    Any body know something about them???
    I want to pair the cab up with my Marshall 1987 smallbox 50watt clone.
     
  2. drbob1

    drbob1 Silver Supporting Member

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    You've pretty much told us everything there IS to know about them: they're mid to late 70s speakers, and they'll sound killer with your Marshall head.
     
  3. Steppin' Wolfe

    Steppin' Wolfe Member

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    From the History of Marshall....section on Celestion speakers.
    "T1871...G12M, 8 ohms, SA3422 coil, SP444 cone, SP651 suspension, resonance 50Hz max to match
    Jensen 1 1/2" coil"

    IF you are looking for a darker sound than the 75hz G12, this will do it.
    There must be a date code on the speaker...two letters----first letter is the month and the second letter is the year for the 1968-1991---- followed by two a number indicating the day of the month. The only Blackbacks I have seen were from 1980...'N" for the year.
     
  4. majicmerlin4

    majicmerlin4 Silver Supporting Member

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    Thanks.....what I was wondering after doing some research they are consider bass cone speakers...In fact the guy I bought the 4x12 from is a bass player who said he bought this rig years ago but kept in storage and till we opened it up was surprised to find these speaker in it. He is in the process of selling off a lot of equipment to move out of state.
    I can see a K code???
     
  5. Steppin' Wolfe

    Steppin' Wolfe Member

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    IF the second letter is a 'K', that indicates 1977. IF the 'K' is the first letter, that is the month of October. Celestion didn't use the 'I' in their dating schemes.
     
  6. Jeff West

    Jeff West Member

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    Yes, I accumulated quite a few of those years ago and quite enjoy using them, they have a pretty good G12M sound IMO. Eight ohms, as you said. They have 55c/s res cones, and the spiders have the fewer, deeper corrugations, unlike a T1221, with greater compliance, the original T list says they were matched to a 50hz resonance. Pretty loud for a G12M, crunchy, and with mids, not scooped. Like many if not all similar Celestions, they seem to change significantly as they get more and more broken in, feel looser and maybe a little louder with use. This T# particularly so, IME.

    When I asked the original Dr. Decibel at Celestion, many years ago, he looked up and determined that T1871 had debut in late 1971, which means that there could be some greenback versions out there, although I've never seen one. I have seen several creamback specimens, all from '74 if memory serves. I think some of these had "444", some R/C cones. Would be cool to find a "4" or "102/14" piece! But most are blackbacks, 1975-79, with K-M "444" cones.

    There is a 16 ohm type, T2633, which appears to have all the same specs except for nominal impedance. These weren't made until the second half of the '70s, all are blackbacks. I've got a couple of these too, I'd say they sound about the same, possibly a little darker but maybe that's the specific ones or my imagination! In direct comparison to T1221, I'd definitely call them darker, but still good for lead. Compared to earlier G12M25 T1511, I'd say they're slightly louder and maybe a touch more aggressive when driven hard.
     
  7. majicmerlin4

    majicmerlin4 Silver Supporting Member

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    Oh...now become clear....1977! I am amazed I stumbled into these speakers in such great condition. And thanks for all the insightful replies quite a history lesson.
     

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