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Celestion Greenback Speakers – An Overview
Ceramic speakers (aka ‘greenbacks’) first appear around late 1964 to early 1965. They have a slightly more aggressive tone compared to the alnico magnet speakers. Amp manufacturers switched to ceramic speakers, mainly because they were cheaper than alnicos, but they also proved to be a perfect match for the edgy, over-driven guitar sound that was emerging at the time. Think Cream era Eric Clapton and Jimi Hendrix.
The ceramic magnets used on Celestion greenback speakers came in four main sizes. The larger magnets have a higher power handling because they can absorb more heat.
- G12H – Heavy magnet (50oz) – rated 30w or 25w depending when made*
- G12M – Medium magnet (35oz) – 5 watts less power handling than G12H
- G12S – Small magnet (28oz) – 5 watts less power handling than G12M
- G12L – Light magnet (20oz) – 5 watts less power handling than G12S
Generally speaking, the bigger the magnet, the louder and bigger the sound will be. The G12H and G12M speakers are the most popular models.
*Power handling increased by 5 watts around late 1967 due to a change in the voice coil design.
Shown below are some of the most commonly found greenback models from the 1960’s & 1970’s.
Note – the speakers evolved through the years, so any small details shown such as the cone stamps, labels, and magnet covers, may be different depending on when the speaker was made.
T1134 (15 Ohm)
The T1134 model was probably the first ‘G12H’ speaker Celestion ever made.
According to the Celestion log book, it was first introduced in Nov 1964 and has an impedance of 10-12 Ohms. However, all the ones I have seen have been 15 Ohm.
They were mainly used by Selmer, probably as a successor to the T731 alnico. The T1217 quickly superseded the T1134, so they may have only had a production run of about 12 months or so. As such they are quite a rare speaker model.
They usually have pulsonic cones stamped H1777 or 003 with the welvic doping on both sides of the cone. Rated 25 watt, with the hammered/oyster paint finish to the chassis.
Notice the unusual solder terminals. The lead wires come through a pair of rubber grommets below and then upto the metal solder points above, very few Celestion guitar speakers were made like this. The change in chassis design is probably the only noticable difference between T1217 and T1134. The log book entry for T1217 does confirm this: “as T1134 but with new type pressure housing”.
T1221 (15 Ohm) & T1220 (8 Ohm)
T1221 is Celestion’s most legendary speaker – the classic G12M speaker with the 75Hz cone. Known simply as “the greenback” ever since its reissue in the 80’s.
The T1221 was the stock speaker in Marshall lead guitar 4×12 cabinets (1960 model cabs) from the mid 1960’s up until the late 1970’s and was also used by many other brands at the time. As such it is an absolute classic speaker and can be heard on countless albums. Famously used by Angus Young and an important ingredient in Van Halen’s “brown sound”.
The date of entry into the Celestion log book is 6th May 1966 – see ‘Michael Doyle – History of Marshall’ – p137, however they were definitely made earlier than this. Marshall were using them in 4×12 cabs by late 1965, and I once owned one dated March 1965.
After a few years of non-production in the 1980’s – what were they thinking? – Celestion re-issued this speaker in the late 1980’s and they are still making them today, available as G12M Greenback.
A popular speaker with classic rock and blues guitarists. People often describe the tone as ‘woody’. This is a tighter sounding speaker than the G12H and compresses nicely when pushed hard enough, with a warm and ‘juicy’ sounding mid-range, and a little more character to the tone than the G12H.
Other variants include the T2168, which is the same as the T1221 but without the plastic magnet cover.
The T1221 went through a lot of changes through the years. The original speakers had a power handling of 20w and had no doping at all on the cones, really great sounding speakers and it is very rare to find those first ones nowadays.
Over time Celestion made small changes to the specification, probably to make the speaker more durable. This included; more doping on the cone edge, and increased power handling. As a result the speaker had more warmth and loudness, but at the cost of other desirable traits such as responsiveness and clarity, in my opinion.
Unfortunately Celestion recently ceased production of their ‘Heritage’ greenback line. Their recreation of the late 1960’s pre-rola period speakers. Look out for them on the second hand market! However, at time of writing the EVH G12M is still in production, and is apparently the same speaker with a different label on it 😉 Grab them while you still can!
T1217 (15 Ohm) & T1234 (8 Ohm)
T1217 is easily the most common G12H Celestion greenback model from the 70’s. It was the stock speaker with many UK brands in the 1970’s, such as Orange and Carlsbro.
Very nice sounding speakers – louder than the G12M and more ‘boomy’, but less compressed and more fluid. Strong in the upper mid range.
To my knowledge the T1217 was never a stock speaker with Marshall. Watch out for the fake T1217’s with white Marshall labels on the back!
Similar speakers are the T1862; as T1234 but no plastic cover, and T1279; as T1234 but with the VOX/JMI colouration and label
The date of entry into the Celestion log book shows 6th May 1966, however I have owned several examples earlier than this, and I have recently seen one example dating back to Dec 1965. Originally they looked very similar to the T1134 with just the gold Rola Thames Ditton labels on the back, but with the standard solder terminals. The familiar green covers appear very soon after this around March / April 66.
The first T1217’s had a power handling of 25 watts and had welvic doping on both sides of the cone. Around late 1967, the doping on the back of the cone was phased out, roughly the same time the voice coils were upgraded by 5 watts.
T1281 & T1534 (16 Ohm) & T1460 (8 Ohm)
I am including T1281 and T1534 together here because they are basically the same speaker. According to ‘dr.decibel’ at Celestion.com, the T1281 is the Marshall labelled version, and T1534 is the standard Celestion label version. These are the G12H model with the 55Hz cones.
The T1281 first appears around September 1966, and was an exclusive model to Marshall. They were used in the 100 logo 4×12 cabs (model 1982). It is regarded by many as “the Hendrix speaker” because he can clearly be seen using these cabs in old footage.
Loud and bassy, with the thick sounding lower mids. Also used by countless other pioneering guitarists back in the 60’s such as Jimmy Page and Ritchie Blackmore. The T1281 is probably the most sought after greenback model of them all!
The original T1281 was a 25w speaker with the white voice coil fomer and the pulsonic cone usually stamped ‘SP444’. Like most G12H of the period it also came with the welvic doping on both sides of the cone.
Quite a different sounding speaker to the more commonly seen 30w version made late 67 onwards. They are tighter sounding and less boomy. It is this 25w version that Jimi Hendrix was likely to be using in his iconic tall pinstripe Marshall stacks, most notably during his legendary Monterey performance in June 1967.
Very rare speakers to find in usable condition thesedays. Surprisingly, Celestion have never reissued this classic 25w G12H used by Hendrix. Come on guys!
T1511 (16 Ohm)
T1511 is the 55hz version of the G12M speaker. It was the stock speaker in Marshall bass cabs (model 1935) from around mid 1967 until the very late 1970’s. They were not exclusive to Marshall as I had originally thought, but are pretty rare to find in anything other than Marshall.
Notice the wide band of doping on the front edge of the cone compared with the T1221.
Note – Pre-rola speakers always have 75hz printed on the labels, and this applies to all 55hz speaker models, not just the T1511. Always look for the white ‘102 014’ stamp on the cone and this verifies that it is the 55Hz cone. Only the later ‘Rola Ipswich’ labels have 55hz printed on them.
T1511 was designed for bass but is a popular speaker with guitar players due to the different tonal characteristics compared with the T1221. It has less mid-range, and more of a scooped tone.
This is another classic Celestion greenback model crying out to be reissued.
T1417 (16 Ohm) & T1416 (8 Ohm)
T1417 is the most commonly found ‘G12S’ model. It was used in various PA cabs and 1×12 combos in the 1970’s, and is apparently dr.decibel’s favourite speaker.
The G12S range are very mis-understood and under-valued speakers in my opinion. They are excellent speakers.
The T1417 is basically the same speaker as the T1221 G12M apart from the 7oz smaller magnet. It has a little less bass, and a little less volume, with a slightly warmer mid range. Ideal for playing at home or smaller venues.
‘Pre-rola’ period speakers can be identified by the small red sticker in the center of the magnet (see first photo).
T1517 is a similar speaker often found in Selmer gear and usually has a G12M sized plastic magnet cover.
T1976 (16 Ohm)
T1976 is a G12H Celestion greenback model often found in old Laney supergroup, Laney klipp, and Dan Armstrong cabinets. It has a 75Hz cone and silver dust cap.
Early examples (circa 71 to 73) with the pulsonic cones tend to have the four ridge spider support, and a solid dust cap.
Later speakers usually have the 6 ridge spider support, and a slightly different dustcap with a small black circular mesh in the center.
The four ridge spider is made from a softer material than the 6 ridge spider. It allows for more cone movement and this results in a louder speaker, with a looser feel.
T1977 (16 Ohm)
Quite a rare speaker model. G12M magnet with the low resonance 444 cone and silver cap. 50Hz bass resonance on the label.
T1886 (16 Ohm)
Quite a scarce G12H model with 55Hz cone and four ridge spider. Usually found in Marshall ‘Artiste’ combo amplifiers from the early 70’s. By the late 70’s they found their way into certain 4×12, and 2×12 Marshall cabs, usually Artiste or bass cabs.
T1886 sounds looser with more fluidity compared to the T1281, perhaps better suited to bass than guitar.
These have a different cone stamp to most other Celestion greenback models. Expect a ‘102/30’ stamp or just a single ‘5’ on pulsonic cone speakers, and ‘5011’ or ‘1105’ on blackback period speakers.
T1871 (8 Ohm)
The T1871 is an 8 Ohm G12M speaker with 55Hz cone, similar to a T1511, but has the softer four ridge spider. Resulting in a more ‘open’ tone and a little more volume. Very nice sounding speakers.
Apparently made as early as 1971, but definitely much more common during blackback era (late 70’s). Probably a speaker designed for Vox, as they seem to turn up in late 70’s AC30’s quite a lot.
The Celestion log book entry suggests they were aiming for the Jensen sound: “SA3422 coil, SP444 cone, SP651 susp, res 50 max to match Jensen 1 1/2″ coil”
T1440 (16 Ohm)
T1440 are probably my favourite Celestion greenback model, partly due to their rarity, but mainly because they just sound so awesome! These are a G12S model with 55Hz cone, and have just a thin band of doping at the cone edge.
They are punchy sounding speakers, with tight bass and clear highs, without the warmth and strong mids of the T1417. Try a pair of these with a 20w or 18w amp and crank that sucker!
‘Pre-rola’ period speakers usually come with a G12M magnet cover and the label ammended with a little red ‘S’ sticker. Another example of Celestion being short of labels during the 60’s.
A similar model is the T1449 which is basically the same speaker as far as I can tell. The Celestion log book entry for T1449 mentions a change in the doping, but having owned both models I could not see or hear a difference between them.
T2115 (8 Ohm)
An 8 ohm G12H model with silver dust cap and 75Hz cone. Often found in front loading ‘Maine’ cabinets and combos. Most commonly found as blackbacks from the late 70’s, and as such the cone is typically the ‘1777’ stamped Kurt Mueller.
T2114 is a similar speaker with an M sized magnet.
Thank You Sir! Fine articles and very valuable information that could have been lost forever.
Hi, many thanks, glad you are finding the info useful.
I have a pair of the T-2168’s.
Thank you so much for that info on them.
I’ll echo Spiders’ comment that you have compiled and saved facts that would have been lost forever.
Another speaker that I love are the Celestion/Vox alnico Silver Dogs.
Hi Dave, and thanks, glad people are finding this information useful. I think the T2168’s are pretty rare, I haven’t seen many of those. The silver alnicos are great speakers too indeed. More info on those here:
Hi, I have a t1221 from the mid 70s its marked 8 ohms but tests at 13 ohms so is this a common misprint?
Hi, yes sometimes they put the wrong labels on. Previous owners could have swapped the backs around too. T1221 is a 16 Ohm /15 Ohm speaker. 8 Ohm would be a T1220.
Thanks for confirming that Brian, great site
Hi Brian, thank you so much for this great site! I’m sure your well versed in sensitivity of all these old speakers. I got two T1511 (1976 Blackback, Mueller Cone) and two T1534 (January 1973 Greenback, Pulsonic Cone) Mixed ’em in a 4×12 and they all seem to have the same sound level. That’s great for my 4×12 mix but shoudn’t the G12H be much louder than the G12M? I’ve just compared the G12H (pulsonic) to my new G12H Heritage (55c/s) which should be the “same” speakers but those are much louder than the pulsonics. Maybe something is wrong with the old ones? Thank you in advance and greetings from Germany
Hi Stefan, sorry for late reply. Not sure the G12H should be massively louder, but you should be able to hear a difference yes. It sounds as though those older G12H might have lost some strength in the magnets. I have heard this can happen, but am definitely not an expert on things like that. Hopefully someone else will read this and maybe offer another opinion.
Brian, is the place of manufacture any form of dating the speaker, for instance, Thames ditton surrey compared to ipswich on the label, thanks , great site for info Tom
Hi Tom, yes and no. The label can help date a speaker, but you need to be careful because the label transition dates can overlap massively. You need to look at the other features of the speaker as well such as the chassis style, date stamp style, cone stamp, colour of the magnet cover. All of those features combined should help date the speaker more accurately. This page should help:
Also be very careful with the whole pre-rola / rola thing, and Thames Ditton versus Ipswich. The truth is they were called Rola Celestion from 1947 onwards when British Rola and Celestion merged. Also they were making speakers from both the Ipswich factory and the Thames Ditton factory from late 1968 to 1975. The labels do not necessarily show this. More info here:
Hope that helps, Brian.
Brian, were there any reissue greenbacks made with solder terminals !
Hi Tom, yes some of the heritage range came with solder terminals. Not sure if they still do though, or if it’s optional.
Thanks, after I asked you the questions I read all of your info on them about the both factories making them until 1975, should have read the info on them first, really great site, thanks again!
Hi Brian, thank you for this treasure of knowledge. Do you like people to send pics? I have a quad of T1927 Red dot 10″ with 1973 date code MF13. Also a quad of T2348 date code LK1 which is 1977. Both quads came from higher end GBX powered cabs with Celestion logos on them. One cab is a bass cab and one is a guitar cab. They sound warm and rich, not flabby at all. Really sweet speakers for clean or overdriven tones.
Hi Bruce, thanks for the info. Yes you can email me some pics no problem: firstname.lastname@example.org. Sounds like some nice speakers. I’m less familiar with the T2348, but I know the T1927 was used in the old Marshall PA cabs quite a lot in the 1970’s. I’ve had a few of those in the past. I agree, they are nice speakers and work very well with guitar, especially if they are the early ones with pulsonic cones.
Saw a pretty uncommon type on ebay:
No mention of this T number on your list, and I have never seen that extra cone on the dustcap.
If this is an original, maybe it is worth adding to the list.
Thanks for your great site, btw!
Hi Thomas, thanks for the info. I will add it to the list.
I need some help and advice about an oddball speaker.
Recently I stumbled across a 1969 T1252 G12L Speaker, still with its original Pulsonic cone.
It seems in fair condition, although I couldn´t hear it, yet.
I am quite familiar with the ususal suspects, own a few G12H ans G12M Pulsonics, mainly 55Hz, but also at least on 75Hz (I usually prefer the 55Hz ones with the amps and playing style I use).
I am not sure what to expect and if to pull the trigger.
Surely, a G12L won´t barely have any bass. I read the treble being kinda dull. Usually 75Hz Greenbacks (namely the RIs) seem to be a bit harsh for MY playing (I don´t consider them harsh speakers per se) and the T1511 is about the most beloved type in my regard. The T1511 has subdued treble itsef. But will the T1252 be even mellower? I learned to like lighter, less bass heavy speaker recently and tend to like mellow speakers as well. But there´s a point when a speaker gets (by design) mushy and inarticulate. How is the G12L in that regard?
Thanks for helping me out before I lay down the money. The seller wants to see more of the upper side of the price range (in my opinion).
Hi Heiko, sorry for the late reply. Yes if you are used to playing G12M and G12H speakers, then a G12L will definitely be missing a big chunk of bass in comparison for sure. To be honest it’s been a long time (several years) since I had a G12L speaker here, so my ears have long forgotten what the tone is like compared to other speakers, but I don’t remember the treble being dull last time I tried one, or the tone being mushy. I think some of that mushy sound you are referring to is often down to the ageing and condition of the cone itself rather than the speaker model, but I understand what you mean. Price wise I would be cautious about spending the big money on G12L model speakers unless you are a Vox collector and see a big collector value in them. The non Vox model G12L’s would be worth a fraction of the price of a similar period G12M or G12H in my opinion.
Hope that helps anyway,