I doubt this will directly answer your question, but...
Our rear A/C on high fan, creates a thrumming sound / vibration. It is due to the fan cage being just a tad out of balance. That said, the first step should be to inspect the fan and ensure there is no debri in it that might cause an imbalance.
Regarding compressor noise... I really don't have a suggestion, unless you can identify a better means of isolation mounts (rubber mounts). Even then, it is still a pretty straight and open shot for noise to come down into the coach through the intake (very noisy!) or dump panels.
Hmmm.... maybe a little judicial application of sound deadening mat???
Tina + Dutch and Bell, Bobo, Harley, Buddy (the dogs)
2011 F350 Lariat 4x4 DRW SuperCrew 6.7L (B&W setup w/Air Lift 5000 Ultimate)
2014 Columbus 365RL (Airflex and Voyager package)
Nights Camped 2014 - 154
, 2015 - 32, 2016 - 4