@atmasphere, isomerically isolated? Does that mean rubber feet? A suspension requires a resonance frequency in and around 3 Hz. Dohmann I think uses 1 Hz vertically and 1.5 Hz laterally.
Put your stylus down on a stationary record, close the dust cover and turn up the volume. Then go look at your woofers. Keep an eye on the woofers as you walk around and even tap on things. With my old Sota I could hit the plinth vertically with a hammer and the woofer would not even twitch. Most woofers will be fluttering from the environmental rumble which is due to anything from the washing machine in the other room to the truck running down the street. Mass might change the amplitude a little but it will not stop it like a suspension will. How much does it really matter? Most people would never know it was there. None of us could hear it directly over the music. However if you have subwoofers and room correction with a lot of power it can cause the drivers to bottom out and can increase distortion. For me it is important because I run my subwoofers up to 120 Hz where the distortion would be obvious. I doubt any of us could hear it under 40 Hz. Of course there is the psychological benefit of knowing nothing can get to your turntable.
