One of the advantages of our active microphones (R-122 MKII, R-122V, SF-24) is their ability to drive long cable lengths, up to 100-200ft. without signal loss. The limiting factor would be the quality of the phantom power being supplied to the mics. A high quality phantom system should provide a solid 48 volts at level of 10 milliamps. Maximum recommended cable length for any passive microphone, including the R-121, SF-12 and SF-1, is 50-75 ft. The louder the source, the less any loss would be evident.