Dimensional room symmetry does not guarantee acoustic symmetry

Evidence

Figure 5.2 gives us more insight into this topic. Here, using an expanded frequency scale, high-resolution frequency-response measurements are shown from each of the five loudspeaker locations in a surround-sound system at the prime listening position. The room is dimensionally symmetrical, but differences in the curves reveal that it is not acoustically symmetrical. A door in one end wall causes it to flex more than the other one at certain frequencies, and a concrete wall behind, but not touching, one of the side walls gives it more stiffness than the opposite wall. The result is asymmetry in the standing wave patterns. — Toole, Floyd E, Sound reproduction- the acoustics and…, 479