Audison Prima ASD BYPASS Plug&Play harness takes the ASD module inputs/iDrive outputs and bypasses them into the HiFi/ HK(674) OEM amp inputs. For the older MOST/digital HK OEM amp, the bypass harness prevents the ASD module from sending a signal into the system but keeps it powered and operating. (Active Sound is BMW’s designation for “artificial exhaust sounds”). NOTE: Not required or compatible with cars using AF BMW ReAMP3.