... intelligibility and tonal clarity in a highly directional beam, even with significant ambient noise. The directionality ... principle, the large acreage transducer array generate narrow acoustic beam, so that the acoustic power source directed ... 1mMain Frequency3.6k HZExtend audio inputMicrophone,MP3LoudspeakerBuilt-inside-3dB Beam width15 degree +/- 5 degreeBeam shapeSymmetry coneDistortion<10% ...