Ver 2.1 November 2009
23
interference from these surfaces is created (as in virtually all other
kinds of speakers).
A second great advantage of the line source is that the vertical
spectral content of music is virtually the same throughout the length
of the line source. Hence, the seating height does not matter with
this speaker; unlike point source speakers where it is important for
the ears to be aligned in relationship with the tweeter.
The third important advantage of a line source is that it attenuates
at –3dB with a doubling of distance whereas a point source
attenuates at –6dB with a doubling of distance.
For example, with a sensitivity of 91dB/watt at 1m, the Genesis 2 is
about average for large loudspeakers. At 2m, the G2 line source
can deliver 89dB/watt, at 4m 86dB/watt, and at 8m 83dB/watt. For
the equivalent point source loudspeaker, it will be 85dB/watt at 2m,
79dB/watt at 4m, and 73dB/watt at 8m. Hence, for a listening
distance of 5m (about 15ft) the line source will appear to be more
than twice as loud as a point source loudspeaker. This is the great
advantage that a line source loudspeaker will have over a point
source loudspeaker in a large room.
As a result the change in loudness of the line source is much less
over a small change in distance. Hence, it results in a much larger
sweet spot as small side to side changes in seating position result
in less of a sonic change than with the point source loudspeaker.
The Genesis 2.2 is also a dipole radiator. The midrange and
tweeter drivers are mounted on a rigid acrylic panel with no
enclosure. This has two advantages: firstly, it eliminates any
enclosure or boxy colorations caused by cabinet vibrations or
resonance.
Secondly, the dipole creates a cardioid radiation pattern (like a
figure-eight), which has its maximum output at the listening position
and behind the speaker itself, and minimum output to the sides in
the plane of the loudspeakers. This very effectively minimizes the
bounce from the sidewalls.
Hence, in conjunction with the line source, the G2.2 has no first
reflection from the floor, ceiling or sidewalls. The net result is that
there are far fewer detail-robbing room reflections from the room
than other types of loudspeakers. With fewer spurious reflections to
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