Hoping to adjust subwoofer level on a Yamaha receiver, preferably with IP or RS232 command, for a customer who has a custom high powered subwoofer so she can turn it up for loud parties and not damage satellites. Can't seem to find it on any RTI driver. If not, know a level controller that can supply feedback to a control system? If not I was thinking of using a Xantech remote volume unit which seems to have preset volume levels.