Specifications and Technical Data Impedance and frequency responses Architects’ Specifications LS18 Accessories Dimensions LS18 with NXAMP TD Controller Frequency Response [a] 35 Hz – 120 Hz ±3dB Useable Range @-6dB [a] 32Hz – 130 Hz Sensitivity 1W @ 1m [b] 107 dB SPL Nominal Nominal Peak SPL @ 1m [b] 137 to 140 dB Peak