Technology Overview

Sound travels at roughly 340m/sec, or equivalently 340mm/msec. So a 1000Hz or 1KHz sound wave has a wavelength of ~340mm. Loudspeakers smaller than a wavelength are practically omnidirectional and send sound in all directions. So a 50mm speaker is hardly directional below 6 or 7KHz. If however an array of such small speakers is driven with the same signal, it is the size of the array, not the individual speakers, that determines the directivity, and a tight beam can be produced. Moreover, if a slight delay is applied to the signal between each successive pair of speakers, the beam can be steered off the axis of the array. Varying the size of the delays also allows focusing of the beam to a point.

Loudspeakers, being nominally linear devices, allow multiple such beams to be impressed upon them, each separately steerable and focusable, and each beam carrying different sound information. This technology, implemented in custom electronics and software, is the basis of the 1... Digital Sound Projector, where 5 or more such beams are focused and directed to walls and ceilings to reflect around the listening room so as to come towards the listeners from all sides, providing a true physical surround-sound experience, almost independently of where in the room the listeners are, and the orientation of their heads.

CML has highly developed knowledge of loudspeaker arrays, and the electronics and software needed to drive them, and to do so at the lowest possible cost, or to create the highest possible quality. Commercial Digital Sound Projectors have been produced with BOM costs lower than $50 in LCD TVs, through hundreds of dollars in Yamaha's hugely successful YSP-series, right up to several thousand dollars (and much more) for Pioneer's PDSP-1 and Professional Audio arrays.

Most recently CML has applied its array expertise to the Dynasonix 3D sound system, by focusing a pair of sound beams on each of several listener's ears while tracking their positions in real-time with a camera, and delivering cross-talk cancelled 3D audio to each listener using their partner Princeton's patented BACCH XTC technology.