MERIT, Benoit, and Guy LEMARQUAND. “Ironless Lowfrequency Loudspeaker Working Under Its Resonance Frequency”. Archives of Acoustics 33, no. 4(S) (December 1, 2008): 59–64. Accessed June 15, 2025. https://acoustics.ippt.pan.pl/index.php/aa/article/view/836.