Since you define "small" as having up to a 6" mid-woofer, I'll assume you will consider small monitors. I recommend you look at the Krix Equinox. It's reasonably small (front dimension is about 7" x 11"), but is an outstanding little monitor. I have been using a pair in my office for about 6 months, and I think they are terrific! They sell new for $600, but I bought mine used on Audiogon for $300.
really small speakers less than 500
I am looking for a really small speaker the smaller the better something like the old ads speakers with a maxium whoofer of 6 inches yes I know bose has some really small speakers but lets talk at least in the league of paradigms to start, thanks Nick