Do you know of small speakers that sound ''BIG'' ?

LS3/5a's sound much bigger than they are (which is tinny).
VSA VR-1 sounds big in a small to medium size room.
NHT SB3 gives great low end for a reasonable size bookshelf.
I think that most small speakers that sound big have a pronounced mid-bass bump that makes them more difficult to integrate with a sub. But if you are talking about a simple near-field set up it can be very pleasing.

Harmonic Precision Caravelles distributed by Star Sound Technology. Zu Audio Tones.

Silverline SR-17's. You won't believe you're listening to a monitor.

No, never heard anything small that even remotely sounded big....unless it came with a sub woofer

Zu Tones, on robust stands, driven by a forceful tube amp. Try to find a pair of used Osiris stands. It will be large and sensation, and when you have the cash, a Mini Method Subwoofer will complete the illusion.

Phil