What makes speaker's sound big?


Does a speaker need to have many drivers or a large driver area to sound big and fill the room?
I am asking this question because I have a pair of tekton design double impact and would like to replace them with smaller speakers and a pair of subwoofer's to better integrate the bass into my room.
I just borrowed a set of B&W 702S. The are good but the just don't make that floor to ceiling sound that I like.
Maybe I have already answered my own question (: But again I have not heard all the speakers out there.
My room measure 15x19' and the ceiling goes from 7.5 to 12.8'

martin-andersen
Meh, that is low fi budget constrained. Everyone knows the best cables are good for at least 72 hours.
yes, but there are those fleeting moments..when that flylined anchovie is swimming beyond ability....count it down....three, two, one....flick the lever drag.....and bang ! Tuna in the can...

IF your reference is well recorded acoustic event in reverberant space and you were there, then moving the illusion ( fleeting as it may be ) is possible, all else is just arguing about which flavor you like. Any 70’s to ? multi-track from Alan Parsons will do..... 
...then for all you tube types, there's Viagra Valve Ventures (VVV to the cognoscenti...)....

It takes but a short while to warm, but once it's hot there's no stopping them...🙄

Ohms (and Walsh's in general) sound big, but placement and room clutter are major considerations...  Omnis' are Not to all's tastes.

Wide baffles seem to help.
Classic-shaped Spendor and Harbeth speakers for instance sound richer and fuller than most.
And certainly the Devore O series speakers sound way bigger and richer than their size would imply.