Not only that, but also their many variations, such as the 55hz “bass” cones and etc. The bottom line is: be careful when using the name “Greenback”.
G12M Early 20w G12M 25w 75hz Celestion first introduced the G12M (medium 35oz ceramic magnet) around 1965 with a power handling of 20w, with options of 8ohms or 15ohms and a resonance frequency of 55hz (bass cone) or 75hz (lead cone).
Most of you probably already know, but it’s worth to clarify this to the “newbies”, alright? ; P) G12M Greenback The old Celestions from the late 60s and early 70s had a green plastic back cover and this is why they were nicknamed “Greenbacks” (no sh*t, Sherlock!
), but “Greenback” does not refer to any specific model.
And this is the point: bass speakers will give you a different tone. It just means it will deal with lower frequencies better.
In other words, bass speakers will give you a “rounder” low end, although many still say they are really… I contradicted myself, but it’s really what some people say), but I would describe them as “deeper” instead.
G12M Blackback 25w 55hz The sound of the G12M tends to be very pronounced on the midrange, with a sweet, woody, warm and smooth sound.The G12M speakers were mostly found in the old Marshall 1960A and 1960B cabs.1969 Marshall 1960A cab with G12M 25w 75hz The 55hz version was used in the 1935A and 1935B cabs (same measures as a 1960 cab – they usually came with a “Bass” logo on the upper corner until the early 70s).1970 Marshall 1935A cab with G12M 25w 55hz and the “Bass” logo G12H An early G12H 25w Note how bigger the magnet is when compared to the G12M The G12H (heavy 50oz ceramic magnet) was introduced as a heavy-duty speaker to handle more powerful amps (in a similar way to the G12M, the G12H’s first versions handled only 25w and then they were powered up to 30w in 1968 – Yeah.It can be a bit confusing – the labels are even more unreliable in this transitional period, so you have to be careful).This is also why the G12H has a certain “bright” character, since the mid frequencies won’t mud it out. The big magnet provides a very strong attack and aggressive sound.I’d say even “percussive”, depending on the situation.Al Ni Co Blue 15w (as used by VOX) It wasn’t until the 1950s that Celestion developed their first guitar dedicated speaker: the G12 Al Ni Co T530 (a.k.a.“Blue”), basically a modified version of the CT3757 radio speaker.It’s simply a “generic” name that was given to the speakers of this period, similar to how “Plexi” is a name to all the pre-1969 Marshalls.In other words, both the G12M and G12H can be called “Greenbacks”.