Mirror-image rooms let engineers locate exactly which wall patches to treat

Evidence

Figure 7.25 shows one method of working out where absorption should be placed in a room to control early reflections. By imagining the relevant walls to be mirrors, it is possible to create “image rooms” that show the direction of the early reflections. By defining a reflection-free space around the listening position and by drawing “rays” from the image speaker sources, one can see which portions of the wall need to be made absorbent, as shown in Figure 7.26. This is very straightforward for rectangular rooms but a little more complicated for rooms with angled walls. Nevertheless, this technique can still be used. It is applicable for both stereo and surround systems, the only real difference being the number of sources. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2299

Categorization

• QUESTION: The image-room technique is spatial/aesthetic in nature — does it generalize to other spatial design problems, e.g. light or heat reflection placement?
• SEED: Could frame an essay on ‘the mirror trick’ as a general design heuristic: imagining mirror-images to place absorbers, doors, windows anywhere in a designed space.