Low frequency audio input isolator specially designed transformer in this unit provides unparalleled low frequency response while providing over 100dB of common mode isolation, to solve even the most difficult sub-woofer installation problems. The zero dB insertion loss also prevents carefully calibrated system levels from being disturbed. High-grade nickel-iron-molybdenum alloy cores for extremely low distortion. Faraday shielded windings for maximum common-mode and RF interference rejection.