Constant-beamwidth-transducer speaker arrays hold stable loudness across listening distance

Evidence

JBL Professional has a series of innovative free-standing CBT products that have found use in sound reinforcement as well as high-end cinema and home theater surround applications. The stability of both sound quality and sound level as a function of listening distance is striking, which makes such designs generally attractive and especially for use as side surrounds (see Section 8.5.4). I have experienced several CBT designs and they all deliver on the promise. One is able to start at a large distance, walk towards the loudspeaker, finally stand adjacent to it, and the sound level hardly changes. It defies instinct. — Toole, Floyd E, Sound reproduction- the acoustics and…, 1294

Categorization

• XREF: Connects to the earlier CBT/Legendre shading material at 1293 and to general psychoacoustic loudness-distance invariance literature.