(SCPC) Audio signals are transmitted via satellite either in conjunction with the video or as separate signals in a variety of formats including audio subcarriers, single channel per carrier and digital sound-in-sync audio.ndreds of single channel per carrier (SCPC) audio signals with individually assigned center frequencies can be transmitted over each satellite transponder. In contrast, a single 36 MHz wide transponder can manage at very most 10 to 15 audio subcarriers because these are relayed at the expense of the associated video power and bandwidth. Each SCPC carrier may occupy from as little as 5 kHz of bandwidth for voice-grade messages to as much as 250 kHz for high fidelity audio.me satellite services occasionally relay the audio portion of their television broadcast is independently of the video in a SCPC format. In a few instances, this SCPC signal may not even be relayed on the same transponder. In these cases, a separate audio FM scanner is required for reception of both the video and audio signals.