Constant beamwidth transducers deliver uniform sound levels over large areas

Evidence

Professional audio engineers are constantly seeking loudspeaker designs that provide controlled coverage of large audiences. Traditionally, this has been done using large horns with varying directivities, line sources and now computer designed, digitally controlled line arrays. One of the clever innovations, the constant beamwidth transducer (CBT) was described by Keele and Button (2005). It is capable of delivering remarkably uniform sound levels over large areas and large distances. I have experienced walking from the far end of a large room up to the loudspeaker, ending up standing close to it, and hearing very little sound level variation along the way. It seemed to defy physics, but in fact it is a clever application of physics. — Toole, Floyd E, Sound reproduction- the acoustics and…, 840

Categorization

• DEFINE: Introduces and defines the CBT (constant beamwidth transducer) concept.
• XREF: Connects to line arrays and horn directivity designs familiar in pro-audio and cinema work.