if you find any info on the sheffield speakers, would you let me know? I have the same cab, I've asked on the peavey forums and here, and elsewhere, and no-where can I find any useful information about the speakers. I'm thinking of doing a straight swap out for 2 x celestion G12K-100 and 2 x Eminence Wizard. If I do this any time soon I'll be sure to report back here with the difference!
Roo