#1
A ten inch speaker....Hey, it sounds like a toy to me even when demo'ed by that Chris guy on Marshall Theatre. He can make every other amp sound great, except the Class 5.

Why they would put one 10" speaker into an amp is totally beyond me.
#2
Quote by axuality
A ten inch speaker....Hey, it sounds like a toy to me even when demo'ed by that Chris guy on Marshall Theatre. He can make every other amp sound great, except the Class 5.

Why they would put one 10" speaker into an amp is totally beyond me.

A lot of people prefer the sound of 10's to 12's, but that's usually with multiples. You may already know this, but if it fits it works. Just measure the cab, if it could possibly be broadened to 12 ten you're fine.
Quote by Cathbard
Quote by Raijouta
Unless its electronic drums.

BURN THE WITCH!!!!!
#3
Single 10s are probably better at sitting in a mix. If you have a bassist, you don't really need the added low end of a 12 or multiple 10s and even then you can still tweak quite a lot of low end out of some 10 inchers. Of course there aren't that many amps that are giggable with 10s, but there are quite a few if you look around.
#4
Celestion 10" G10F-15 is hardly a toy speaker, though I havent' played around much with the class 5, only heard the greasy brats at guitar-denter faux-brootz there way through some nausiating rendition of whatever blackmetal misanthrope is "top of the pops" that week...

I don't know for sure mind you, that just tends to be the case...

(rant over )

Anyway, there's lots of 10" options that may fit it's characteristics and your desired tone far better; Celestion is not the end-all be-all speaker.

And of course, an extension cab or 12" might do the trick, too...
Tube's right, get out a tape measure and see what's what; if it's close, some 12"s are smaller than others, eg, a neo might fit better than an Alnico, and certainly better than a fane or EV...