It was only a matter of time before someone put exhaust pipes on a speaker. What you're looking is French Haliaetus's Firebird speaker which shuns normal ports for what they call "acoustic nozzles." I like exhaust pipes better, but there website claims there's some actual science behind these shiny funnels, saying this of their work with the European Space Agency:
"In fact, thermo-dynamicists are well aware of the need to control supersonic flows which should have the highest speed possible in order to increase the power of a rocket engine."
European Space Agency? Rocket engines? The biggest bunch of BS ever? I have no idea. The nozzle is said to lower bass frequencies, but the Firebird is rated at a very typical 50-20k Hz +/- 3dB with 87dB and 6 ohms, so nothing really special there. Of course, the nozzle may sound brilliant, who knows. Check out their website for a lot of acoustic verbiage that is way over my head.
Below is the Firebird bookshelf sitting on top of the Booster subwoofer. The Booster appears to use the nozzle as a horn rather than a port. Bass goes down to 25Hz and fires directionally unlike a typical subwoofer that attempts to disappear. Interesting. I don't see any prices on their site (or distribution in the states, for the matter). Check out 6Moons for more discussion. Of course, if anyone out there has actually heard this thing, chime in.