FC104 4" Loudspeaker 10W @ 8 by Atlas Sound.
This compact, full-range, 4" loudspeaker is fully equipped with a damped, high-compliance cone and results in an excellent low frequency reproduction and smooth extended response. It also offers a wide dispersion angle which reduces the number of loudspeakers necessary to achieve total coverage in low-level distribution systems. The 10-watt, 8-ohm model (without transformer) offers a frequency response range of 150 Hz to 17 kHz, sensitivity of 94dB (at 1 watt, 1 meter) and a dispersion angle of 135 (-6dB, 2 kHz octave band). The unit contains a 10 oz. (283g) ceramic magnet with a flux density of 10,500 gauss.