Trio15

The model that made PureAudioProject's name, and the clearest statement of what an open baffle is: two 15-inch woofers and a mid/high module bolted to three slats of oak, bamboo or HDF, with nothing behind them. No box means no box colouration and no port — but also no boundary reinforcement, which is why the brand asks for 60 to 120 cm of clear space behind the panel. The 15-inch drivers are PureAudioProject's own, made with Eminence and specified for dipole loading; the module in the middle is picked at order from a wooden horn, a Voxativ or AER widebander, or a 10-inch coaxial, so two Trio15s can sound quite different. It arrives flat-packed and you assemble it with an Allen key, and the first-order crossover sits on gold screw terminals so its components can be swapped by ear. 96 dB, so a few valve watts will do.