The Cinnabar (a play on "Cinema" and "Bar") project began as the result of a line of thinking that was sparked by seeing integrated home theater 'speaker bars' in large retail stores. These bars usually combine all five channels of home theater audio into a single speaker using some DSP and phase trickery to convince your ears that you're hearing real surround. However, my experience has been that you only hear 'real' surround audio from real surround loudspeakers, and unless you're in a narrow sweet spot, the surround-sound effect just doesn't 'gel'. However, it's still possible to combine the front three loudspeakers into a single bar under a large widescreen television and still maintain the speaker spacing needed to get a convincing stereo experience.

But what about bass? Most systems that integrate subwoofers into the speaker bar generate so much vibration from the mass of the cone that it can jeopardize delicate electronics and mechanisms in the TV itself, particularly in LCD and DLP projection TVs. Air, on the other hand, can transmit pressure while weighing far less. The Cinnabar loudspeaker integrates a subwoofer using a unique type of low-frequency loading, the Mass-Loaded Horn (which, I believe, is what Gemme Audio has dubbed 'Vflex' in their own products). A mass-loaded horn still operates as a quarter-wave resonant system, but a sudden constriction and an acoustic mass simulate additional 'length' to the waveguide, while delivering benefits in LF sensitivity which can be traded for additional bass extension by tuning below the drivers' resonant frequency. In the case of the CineBar, the simulated design uses mass-loaded horn loading to provide bass extension to 35 Hz (-6dB) from a pair of 4" drivers with a 55 Hz free-air resonance. The small drivers introduce very little vibration, while the horn waveguide does the work of a broadband resonator, and as simulated, the design reaches its excursion limits at 100dB at 40 Hz with 25 watts applied. The mass-loaded horn design promises to be a very effective method of incorporating subbass reproduction into the speaker bar while avoiding the transmission of vibration up into the television. The design will fit completely underneath a 40" LCD television.

The filtered full-range concept worked extremely well in the Whetstones single-driver monitor loudspeakers, so I plan to apply it to the Cinnabar as well for the midrange and high frequencies. There's no dragon's blood or other audiophile idolatry involved, just good physics.

Progress: Drivers on hand, enclosure simulation done, crossover simulation is next.