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
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. 
IMHO, you can't get a bigger sound than when a speaker completely disappears.   I've never heard a 15" driver that imaged well or disappeared and they sound flat & lifeless at low volumes.

Have a play with placement.

http://www.cardas.com/room_setup_rectangular_room.php