The stand-mounted CDM1 NT for the rear/side channels is a two-way, vented-port system with the Nautilus tweeter and one 6.5" woven Kevlar bass/midrange driver. The Kevlar mid-bass cone seen in many of B&W's more expensive speakers contributes to the open midrange and full, clear bass produced by the CDM1 NT. B&W's Nautilus tweeter-on-top technology ensures that the sound remains open and time-coherent, and that the stereo image is presented with unparalleled three-dimensional accuracy.