Blew a speaker at our last jam

hywelg

Plexi 1987 combo with a G12-m Heritage/Anniversary whatever (the 20w one) and a gold. Obvoiusly an imbalance of power handling and I always intended getting an H to go with the M.

I am assuming its the M thats blown, (we are loud but not that loud)  i didn't get chance to check it over and I leave the combo at the studio, since my OTS is with @DJH83004 for a service.  I have a new Creamback M thats waiting for a job so I am thinking to get a Creamback H to go with it. Anyone care to talk me out of that plan? Not that fussed about the Gold TBH so that'll end up back in its box.

ICBM

You've almost certainly blown the G12M - a 20W speaker in a pair driven by a 50W amp is not a good idea regardless of the other speaker. The power rating of the cab is twice that of the lower-rated speaker, not the sum of the two.

Creamback G12M-65 & G12H-75 is a great combination - very like a G12M-25 and a G12H-30, but slightly tighter and darker, and obviously with a lot higher power handling - 130W, so completely safe with a 50W amp.

I think @rockmonster may have a G12H-75 for sale...

hywelg

ICBM said:

You've almost certainly blown the G12M - a 20W speaker in a pair driven by a 50W amp is not a good idea regardless of the other speaker. The power rating of the cab is twice that of the lower-rated speaker, not the sum of the two.

Creamback G12M-65 & G12H-75 is a great combination - very like a G12M-25 and a G12H-30, but slightly tighter and darker, and obviously with a lot higher power handling - 130W, so completely safe with a 50W amp.

I think @rockmonster may have a G12H-75 for sale...

I was aware of that, but I do have Powerscaling installed and very rarely have it anywhere near max.

Winny_Pooh

hywelg said:

ICBM said:

You've almost certainly blown the G12M - a 20W speaker in a pair driven by a 50W amp is not a good idea regardless of the other speaker. The power rating of the cab is twice that of the lower-rated speaker, not the sum of the two.

Creamback G12M-65 & G12H-75 is a great combination - very like a G12M-25 and a G12H-30, but slightly tighter and darker, and obviously with a lot higher power handling - 130W, so completely safe with a 50W amp.

I think @rockmonster may have a G12H-75 for sale...

I was aware of that, but I do have Powerscaling installed and very rarely have it anywhere near max.

Get the pair anyway. Most tube wattage ratings are Before clipping... and there are very little speakers between 35 and 60 watts (wattage a speaker can handle is in ways really how much heat it can dissappate rather than just the cone only being thicker.)

hywelg

Well thats a pisser. Just set about dismantling the 2x12 combo to start moving speakers around and I find its the Gold that has blown!!!. Both I and @ICBM would have lost money on that bet.....

Changes plans somewhat.

Will a G12H-30 be ok with a G12M (anniversary 20watt) for a 50 watt 1987? My gut says no.

All my plans for moving/pairing speakers and what I was going to buy are now needing a rethink.

ICBM

hywelg said:

Well thats a pisser. Just set about dismantling the 2x12 combo to start moving speakers around and I find its the Gold that has blown!!!. Both I and @ICBM would have lost money on that bet.....

Yes - although with one small caveat.

I've come across two UK-made Celestions (both Heritage G12H-30s) with a manufacturing fault that has caused them to go open circuit, where the cone braid joins the voice coil. Unfortunately this can't be got at to repair without destroying the cone, and I only discovered it because I have a habit of 'post-morteming' things which have failed unexpectedly, in case there is an outside cause which needs to be investigated so that the replacement part doesn't just go the same way.

I've never seen that on any Chinese-made Celestion. And as far as I know at least the earlier Golds were UK-made...

hywelg said:

Will a G12H-30 be ok with a G12M (anniversary 20watt) for a 50 watt 1987? My gut says no.

I would also say no, really - unless you're attenuating it to below 40W with the power scaling, in which case it should be fine.

I'm also not totally convinced that the G12M-20 isn't actually a relabelled G12M-25, for purely historical reasons! Although even then, 50W Marshalls are capable of blowing Greenbacks in a pair.