Lexicon CP-1 Theory Of Operation page 14

This works extremely well when the room is well damped and the listener's
head is correctly positioned. The first order devices described earlier
required the listener to sit on the center line between the loudspeakers, and
to arrange the angle between the speakers to correspond to the modeled
delay. Although the processor provides adjustments to compensate for off-
center listening and for varying speaker angles, maintaining a consistent
listening position is still important and becomes more so with increasing
frequency. With wide speaker angles, a movement of as little as 1 inch can
make a perceptible difference. Fortunately, the effect is usually fairly good
everywhere within a zone about one foot wide.
To achieve the fullest Panorama effect, your main loudspeakers should
have good imaging. The smaller speakers that tend to be used with video
systems may have an inherent advantage here but the most important
requirement is that the two speakers have identical frequency response and
symmetrical dispersion. It is not necessary, or desirable, to turn your
listening room into an anechoic chamber but moving the speakers away
from the walls can be helpful, as can adding absorption (as provided by
carpets, curtains and/or sound-absorbent panels) to reduce the reflectivity
of the floor, walls and ceiling.
In a well-damped room with loudspeakers mounted on stands away from
the walls, the Panorama effect can be very exciting, giving the closest
possible approximation to the actual hall used for the recording. With true
binaural recordings (made with a modern dummy head with accurate
external ears and proper equalization) the playback can be uncannily
realistic. And, unlike previous versions of this technique, the Panorama
mode adds virtually no coloration to the original signal.
Multi-Channel Music & Cinema Systems
Imagine a click in the left speaker . . .
Sound from speaker L travels to the left
ear and also to the right ear, a time t
later.
If we supply a negative delayed signal to
the right speaker, this crosstalk can be
canceled.
Theory and Design
11