Source at these higher frequencies and is designed to be able to produce enough
SPL to match the output capabilities of the Sage Cinema series.
This high frequency module uses 2 basic concepts to achieve high SPL for short term
peaks, long term power handling for extended use, extended high frequency
response past 20kHz, and excellent on and off axis response that easily blends with
the Sage Cinema line source loudspeakers.
The first concept is power shaping: By configuring the 3x6-Bar PMD in an “MTM”
(mid-tweeter-mid) arrangement and using a passive contour network between them a
novel approach to increasing high frequency section power handling and maximum
SPL, without sacrificing dispersion, was developed. This approach encompasses both
power shaping and frequency response tapering to maintain the 6-Bar PMD off-axis
response whilst increasing the power handling by at least a factor of 2.
The second concept is heat wicking: Iterative heat-sink configurations were
developed for the 6-Bar motor, until an iteration was developed that passed the CEA
426B test with no measured effect on performance. The final heat sinks were
standard horizontal fins attached to the rear motor structure with a large heat
spreader to increase thermal mass, and a black aluminum grate installed in close
proximity to the front of the diaphragm and in contact with the front magnet, with
ridges bent into the mesh to aid in heat dissipation (the technique is called “heat
wicking”). The entire thermal assembly is assembled with the PMD as a sandwich
including a large front plate of aluminum that acts as both a structural member, to
hold the motor structure and magnets in place, and also a heat sink to allow the heat
generated by the magnets to be dissipated out from the enclosure and into the room.
The above design choices give the Hybrid Line Source loudspeaker three primary
features for easy integration within a Sage Cinema install with a hard screen.
•The 24” planar panels combined with the high frequency planar MTM give the
same detailed, low-distortion clarity of sound as the Sage Line and Point
Source modules.
•The large length of the dual 24” Line Source PMD panels help to minimize
room interaction/influence just as in the Sage Line source loudspeakers down
to the lower midrange frequencies.
•The high frequency MTM is used to create a wider horizontal coverage than a
rotated Line Source at higher frequencies and is designed to create enough
SPL with high power handling to match the power of the Sage Cinema series.