MIL-DTL-25547 Loudspeaker, Permanent Magnet Ls-211/Aic-13This specification covers one type of loudspeaker, designated loudspeaker, permanent magnet, LS-211/AIC-13. This loudspeaker is a horn type unit with a frequency response of 200-7,000 Hz, nominal 16 ohms voice coil impedance, and a 20 watt peak power output \(see 6.1\).