Mirror Sources and Wedge Space Field

Abstract

Shadow-casting convex corners are problematic in the mirror source procedure. In Chap. 21 the problem of shadow-casting convex corners in the mirror source method was resolved through the application of the principle of symmetry-superposition (PSS), which reduces the field evaluation in convex room corners to two field evaluations in concave room corners, each between one of the original flanks and the central plane of the original wedge space. If the original wedge has two absorbent flanks with different absorptions, i.e., the admittances of the flanks are G ₁ ≠ G ₂, the problem must be “symmetrised” prior to application of the PSS. Two methods for this sub-task are described in Sects. 21.1 and 21.2. According to that description, the task with unsymmetrical absorption of the flanks is reduced to the solutions of two symmetrical problems with same absorption at both flanks. Until one can apply the mirror source method on concave wedge spaces with one absorbent and one “ideal” flank (hard or soft) one must subdivide the original task into two or four sub-tasks (Fig. 22.1).