Question about pre rola G12H speakers

Discussion in 'Amps and Cabs' started by gnugear, Jun 9, 2006.


  1. gnugear

    gnugear Member

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    I picked up a quad of what looks to be 55hz G12H30s from 1970. There are no lables and the frame has T1281 stamped on it.

    Aren't G12Hs louder than G12Ms? Mine have the same volume as my Greenbacks and a similar tone. Did Celestion ever use the T1281 frame on G12Ms?
     
  2. Scumback Speakers

    Scumback Speakers Gold Supporting Member

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    Not likely, sir. But you have to understand that the magnet determines the sensitivity of the cone. Celestion used 102 003 cones in both the T1221 G12M and the T1217 G12H30's, difference was the magnet and suspension used. M's have 96/97 db sensitivity, H's have 99/100db sensitivity, which should be about 50% louder than the M's.

    You can't fairly compare M's with 1777 cones to 003 Pre Rola cones, as 1777's are louder than 003 cones. You also can't compare 444 bass cones used in the T1281's to 014 cones in the Pre Rola's for the same reason.
     
  3. gnugear

    gnugear Member

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    Okay, let me throw this curve ball at you ...

    The auction said it had reconed H30s. When I opened the cab, the cones looked original, but the white printing had these numbers ... 017 014.

    Do you think they were reconed with pulsonic G12M cones on a T1281 frame? I'm not sure if Celestion had recone kits and the guy said they were done a long time ago but didn't give a date.

    Regardless, they sound great ... I'm just very curious about the origins!
     
  4. Scumback Speakers

    Scumback Speakers Gold Supporting Member

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    Well, from what I know of Celestion Pre Rola recones, they had 102 014, 102 003 and 102 002 (10") Pulsonic recone kits. These were available in the 70's, and for all I know there are still some around. I bought two 10" Pre Rola's that were reconed with the 102 002 10" kits just a year ago, but you could tell they weren't installed that long ago, as they still had the "new smell" going for them. Old recones don't smell much, if you know what I mean.

    As for newer recones from Celestion, in the late 80's/early 90's they had their 6402 recones (sound great, I have some in both G12M and G12H's), then their current offerings in H1777 (75hz Reissue in both the G12m and G12H Anniversary type speakers), and 444 55hz cones used in the Vintage 30's. These are, obviously, the same as the G12M's and H's made in China today.

    So, while it's possible that you got some real Pulsonic recone kits (and bully for you if you did!), with the cone #'s you've posted, I doubt it. Unless you read the cone #'s wrong, or someone has gotten "artsy" with a white stamp, and faked them.

    Best bet is to refer to that Celestion Greenback thread I did last year. Here's two pics of an orginal:
    [​IMG]
    [​IMG]
    This one is a repaired cone, but you can see how the cone # is supposed to look. Take a gander inside at yours and let us know...
     
  5. 908SSP

    908SSP Member

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    I was comparing speaker cabs a couple nights ago I was surprised to find that the H's were no louder then the M's. My M's are all pre-rola 1970 date code 012 003 cone codes the the H's were all transition speakers 1972 with 012 014 cone codes. The M's are very warm smooth with no peak to speak of. The H's were warm had a slightly more low bass and a peak in the upper mids still a smooth textured sound. I use an A/B switch to make very quick comparisons.
     
  6. gnugear

    gnugear Member

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    I'll post a pic tonight because the suspense is killing me.
     
  7. gnugear

    gnugear Member

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    That's exactly what I'm hearing!
     
  8. Scumback Speakers

    Scumback Speakers Gold Supporting Member

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    I'm surprised to hear that you guys think the volume is the same between yours, as there's a definite difference in the volume of my H's to my M's.
     
  9. gnugear

    gnugear Member

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    Yeah, I used a hot plate (set my amp to 8ohm) and switched back and forth. I've got some blackback 55hz H30s and they're DEFINITELY brighter and louder. I'm going to take pics tonight and reference the ones you posted because I'll be able to look at things like the magnet size, etc,.
     
  10. Scumback Speakers

    Scumback Speakers Gold Supporting Member

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    Much as I hate to say it, if your H's are the same volume as your M's, that probably means they were "beat to death", or you have the world' LOUDEST M's.

    Whenever I play out with my old G12M's I have to turn my master volume on my Super Goldtone up to 6, but with my G12H's I set it at 4.

    I've had really tired G12M's and G12H's I've bought...so I know what you're going through.
     
  11. carbz

    carbz Supporting Member

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    Quit foolin around with those ragged ole celestions and do yourself a favor and get some scumbacks. Jim is the man!:D
     
  12. gnugear

    gnugear Member

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    Ooh, that bums me out. What else do you notice with spanked speakers? The volume doesn't bother me.
     
  13. Scumback Speakers

    Scumback Speakers Gold Supporting Member

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    The definition and articulation are less on speakers that have been beat. Generally this is due to having too much power presented to them, like the guys who think it's safe to run an old Plexi 100 watt on 10 with an overdrive into four 25watt G12M's...or G12H's.

    I always try to recommend that people give themselves 25-50% more headroom on their speakers than what the amp says it is. Which means if you're diming a 100 watt (that might put out as much as 180 if it's real healthy) into four 30 watters, you're already running it real hard if not over the limit. Marshall built those 100 logo 4x12's to be run in PAIRS with their 100 watt Plexis.

    But, there are those who like to play "on the edge" and risk it...that's why alot of old Pre Rola's are sold in pairs or threes, depending on how they're wired, they blow one or two when they go past the point of no return on the wattage.

    The other thing you'll notice is what seems like a really attenuated high end, some mushy low end, and the mids get mushy, too.
     
  14. gnugear

    gnugear Member

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    Okay, here are some detailed pics. The larger magnet cover definitely looks like an H30. Let me know what you think about the rest.

    [​IMG]


    [​IMG]


    [​IMG]


    [​IMG]

    [​IMG]
     
  15. Scumback Speakers

    Scumback Speakers Gold Supporting Member

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    Dude, that's the right cone there. Date codes of June 24, 1970, Pre Rola for sure. They just didn't stamp your cone code completely, but you've got the best cone they made. I think I'd go try them one by one with a low watt amp and see how they are individually. That's what I do when I get them, then I take them to OCSR for a professional test, just to make sure.

    As far as originality, they look original to me, as far as looks from the back are concerned. If they look like this from the front, you've either got original cones, or some of the best cones in a recone I've seen yet (or the best fakes).
    [​IMG]

    Time to test them out individually. It only takes one bad speaker to interfere with the other 3...take my word for it. Maybe only one is beat, but the volume thing worries me. They should be quite a bit louder than the G12M's. Even accounting for age, H's should be at least 25% louder than M's, but 50% is more like it, in my experience. Good luck. Email me or post again if I can help you out with this further.
     
  16. gnugear

    gnugear Member

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    Okay, I rewired the cab like all my others just to make sure everything is apples to apples. The cones look like yours from the front and actually look pretty darn new to me. The cab has average wear but the inside was pristine. I did some speaker swapping and put my pulsonic G12Ms in my 68 straight, played that next to this '70 straight, and next to that played my JCM800 straight (with basketweave grill) which has the blackback 55hz H30s.

    The blackback cab is the loudest/brightest/crunchiest by far. The 68 with greenbacks the quietest, and the '70 falls right in between the two. They're definitely a warm speaker. More like a richer greenback than what I'm hearing from it's blackback cousin.

    Maybe that's the way they're supposed to sound and I was just expecting something different. I can hear "Machine Gun" in there for sure! :)
     
  17. Topcat

    Topcat Member

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    Just for the hell of it-What is the stamp # on your blackback cones?

    As Jim said, those H's look to me to be the original goods. For my taste, the best sounding speakers out there!

    I also agree there should be a bit of a volume difference but the difference you are describing in your last post fits the 'bill' for the sound variance bt. the two types.

    Sounds like you have some killer equipment-have fun!

    Terry
     
  18. gnugear

    gnugear Member

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    You know, I think I'm just being totally anal and neurotic. After flipping back and forth, the two H30 cabs are pretty close in volume ... it's just that the blackbacks are a lot brighter so it gives the impression of increased loudness (lots of boom and sizzle). :crazy

    I've been messing around with all the cabs and these things sound great! They're like a relaxed pair of jeans where the blackbacks are like a new pair of jeans. I was using my Les Paul earlier and just switched over to my strat and the speakers just LOVE the strat. I'm just going to shut up and play my damn guitar!
     
  19. gnugear

    gnugear Member

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    That's the only one that still screwed shut ... and my wrist hurts from all this speaker swapping!
     

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