Appendix
E – LS-77 in OptiArray configurations
E.1 Introducing AMR's OptiArray® scalable acoustic system
Above and beyond the role of an exceptional quality midfield monitor, the AMR
i. The larger a room the louder must a speaker play for a given sound level at the listening position.
iiThe larger a room the more and to lower frequencies must the speaker directionality increase to maintain the same ratio between direct sound (that of the recording - wanted) and indirect sound (reverbrations in the room, - unwanted).
Large listening spaces invariably require more acoustic power applied to the air volume in the room to excite the same amount of pressure change (a bottle of beer will nearly fill a pint glass, however in a large bucket it will barely moisten the bottom), this much is quite obvious, so the need for more output from the speaker as rooms get larger is simple and intuitive.
However, large listening spaces are invariably also less well damped, in an acoustical sense, than small ones. This and the much longer dimensions with the thus increased delay between reflections lead to much longer reverb times in the room. The room reverbrant field (that is sound radiated and
For a striking example compare the sound of a portable radio in an equal size empty room and one well furnished. In the empty room the sound will be clattery, echoy, phasey and indistinct as well as subjectively too bright. In a normally furnished room with carpeted floor the sound will be much more natural. Ideally we wish to keep the unavoidable contribution of the room sound over the direct sound below the threshold where the room influenced sound overwhelms the direct sound.
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