Just wondering; if I have a small speaker with not a lot of bass, and I have another small speaker with not a lot of bass and run them together, will there be a percieved increase of bass frequencies? Since 4x12s usually sound enormous compared to a 1x12 even.
we seriously have no idea what you're asking or what species of speakers you speak of.
I have a ZT Lunchbox. They just made a Lunchbox Cab which gives you another 6.5" speaker you can shove under it giving you the world's smallest giggable stack. I'm wondering if having more speakers also helps fill out low end; say I have 2 10 inch speakers, would that igve me as much bass as a 12 inch speaker, etc.?

Keep in mind the speaker doesn't work like a normal speaker before people come in with 6.5" NO WAY CAN THAT PUSH AIR.
No Way Can That Push Air
LTD Alexi-600 White & Black
LTD Alexi-200 Black(Death Adder pickup & Gold OFR)
Agile Interceptor Pro 727 7-string
Jackson JS30RR rhoads
Jackson DKMGT
Squire telecaster

Bugera 6262 212 loaded with WGS veteran 30's