The new line of modular speakers from Artcoustic is designed to take care of that.  Each speaker in the line can be purchased with a custom baffle that takes up far more space than the speaker itself would.  You can pick it up in black to create the illusion of larger speakers, or with an art print to hide the speakers entirely.

The Modular One is the smallest speaker yet from Artcoustic, coming in at 9.8 inches high, 3.1 inches wide and just 2.1 inches deep.  It's also the cheapest of the new line at $680. Also available are the Modular L+C+R, a smaller version of the DF-Multi and starts at $1,130, and the $1,220 Modular Cinema, which resembles a sound bar in both style and function.