The DGRC (Digital and Geometric Radiation Control) principle enables assigning a large number of loudspeakers to a limited number of electronic channels. It was introduced in 2006, and is now used in digitally steerable column loudspeakers. In this paper, we propose a very simple and straightforward implementation of this principle in a passive column, where delays are approximated with all-pass passive circuits. As a result, the column is placed vertically (not tilted) and radiates a wave front which ensures high speech intelligibility and homogeneous SPL coverage. We present the design of this column, as well as modeling and experimental results. Finally, we discuss its advantages in terms of visual integration, acoustic performances, and cost effectiveness.
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