Pair of BishopSound Gamma 10 Passive 350W RMS 8 Ohm Speaker Posted on November 11, 2023 by admin 350w RMS – 55Hz to 20KHz – 125dB SPL! For installation, the Gamma Series in its 6″ 8″ and 10 formats gives you all the British weather protection and the best of British full-range, sweet sound.