Fig. 2.

: Control for the precision of acoustically evaluated distances. A side view of the environment (speaker – orange rectangle, microphone – orange circle). The manually measured distances: $R_{\mathit{arena}}$ is the radius of the arena. $X_{\mathit{sp}}$ is the distance of the speaker׳s membrane from the wall, due to the 35° tilt. $X_{\mathit{sp}\leftrightarrow \mathit{mic}}$ is the horizontal distance of the microphone from the loudspeaker. $h_{\mathit{sp}}$ is the height of the speaker׳s membrane center. $h_{\mathit{mic}}$ is the height of the microphone. $h_{\mathit{sp}\leftrightarrow \mathit{mic}}$ is its vertical distance of the microphone from the speaker. Using the Pythagorean theorem we calculate $d_{\mathit{sp}\leftrightarrow \mathit{mic}}^{\mathit{Empirical}}$, the distance between the speaker׳s membrane and the microphone, based on the manual measurements. $d_{\mathit{sp}\leftrightarrow \mathit{mic}}^{\mathit{Acoustic}}$ is the acoustically evaluated distance (89.8 cm), deviating 0.2 cm (0.22%) from the manually measured one (90 cm) (For interpretation of the references to color in this figure, the reader is referred to the web version of this article).