10" speakers vs. 12" speakers

I've always wondered why (for vintage rock tone), 10" speakers seem so popular whereas guitar cabs are primarily loaded with 12" speakers. is there a theory behind "less is more" when it comes to bass cab speakers?

the reason why i ask is that the guitar player in our band and me are switching instruments for a lot of songs, and i'd rather not play through his rig (which i currently do) and just have my own setup where i can play bass or guitar through.

i'm thinking about using a 4x12 guitar cab and a radial headbone head switcher. but i guess i could also use my bergie 6x10. apart from checking it out and using my ears (which i will do), does anyone have any well formed opinions on the matter?

 

too funny...thanks for the edumacation!

at home i play my bass through the clean channel of a Peavey 5150 II half stack and it sounds fine. just for ****s and grins i'm going to see if i can dial in a nice guitar tone through my SVT rig to see if i could get by with that. I mean SRV often played through a fender bassman, so why not?