The 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. * Eliminates the inherent ground noise coupling mechanism. * Common-mode ground noise rejection of 105 dB at 60 Hz. * Extended low frequency response: -1dB at 0.4Hz, -3dB at 0.15Hz.