M. NIEWIAROWICZ and H. ŁOPACZ, “Directional properties of the loudspeaker systems with analog and digital crossover networks”, Arch. Acoust., vol. 33, no. 4, pp. 541–551, Jan. 2008, Accessed: Jan. 18, 2026. [Online]. Available: https://acoustics.ippt.gov.pl/index.php/aa/article/view/551