Don't know what trailer you have or what year, but our front Dometic A/C in our 2013 Columbus was noisy and Dometic sent me a kit consisting of Some rubber bushings, a bracket, and a different designed compressor motor designed to reduce the noise and vibration. It helped a lot, but it still takes some getting use to as it is a few feet from you when you're in bed, as already mentioned.
2013 Palomino Columbus 320RS
2007 Dodge RAM 2500 6.7 Cummins
Reese 15K manual slider
M.I.L. in Florida for good!!