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: Apr. 26, 2025. [Online]. Available: https://acoustics3.ippt.pan.pl/index.php/aa/article/view/551