Exhaust sound with remote valve on BMW E38 740 M60 4.0 V8

This is a legal cat back setup.
Switched valves are installed in 2012 between X pipe and mufflers and working fine til today.
Giant Exhaust resonator removed and replaced with X pipe in 2013 to improve the sound. Original mufflers are intact.
Wireless remote is added in 2023 for convenience.

[@DurianGarage]

See description for setup detail