Fig. 5: SPL directivity, attenuation of SPL with distance, and stability of flat and rolled loudspeakers.
From: Scalable and eco-friendly flexible loudspeakers for distributed human-machine interactions
a, b Experimental setup for SPL directivity measurement (scale bar, 5 cm). a Flat loudspeaker with a surface area of 9 cm2. b Rolled loudspeaker with a fixed projected area of 9 cm2. SPL polar plots under fixed driving frequency of 6 kHz and voltage of 17.7 Vrms, 53.1 Vrms, and 88.4 Vrms for (c) a flat loudspeaker and (d) a rolled loudspeaker. e Attenuation of SPL with distance up to 30 cm for the flat and rolled loudspeakers, under driving voltage of 70.7 Vrms and frequency of 6 kHz. f Output stability of flat loudspeakers (new one and after 108 days in lab conditions of ~ 25 °C and ~ 60%RH) and rolled loudspeaker under continuous 11 working hours, with driving voltage of 70.7 Vrms and frequency of 6 kHz.
