You may want to 'go naked', that is put the turntable out of the room where the speakers are. At least try it to see exactly what differences are produced. Coupling and de-coupling still does not eliminate the acoustic engery that hits the base, arm and cartridge, only complete isolation of the entire rig does. An alternate is to put a screen/box over the rig.
Monaco TT with Halcyonics
I was wondering if anyone was using one of the Halcyonics active vibration control devices with their Monaco TT. This question is specific to the Monaco as I know others have used the Halcyonics to good effect with other TT's. I have no obvious vibration issues which appear to be affecting the performance of the Monaco but vibration will be getting through and its minimization may indeed have a sonic benefit. A lot of money to spend on a hunch that it may do something and an improvement with this TT may be very subtle so if anyone has experience positive or negative I would be pleased to hear it.