Suspensions on turntable...really effective?

Sorry for the newbie question, but just wanna make sure I get it right...resonant frequency is the frequency that passes thru the whole suspension and gets transferred to or received/absorbed by the plinth, platter or whatever is above the suspension?

So, frequencies other than that resonant frequency gets isolated/inhibited/blocked?

Or only frequencies above the resonant frequency gets blocked?

Frequencies above the resonant frequency get attenuated at a rate determined by the low pass filter so that if the resonant frequency is 3 Hz the effectiveness of isolation at 5 Hz is very poor say 5-10% but at 20 Hz the effectiveness is up around 95%. The iso system acts like a classic mass-on-spring mechanical low pass filter.

Thank you, geoffkait. 

Hate to put these tables on the spot, but these 2 are reasonably priced (for me)...anybody have an opinion on Michell GyroDec and SOTA Satellite's suspensions? 

GK, Gases are compressible too.  Air is a mixture of gases; would it be so wrong to think of air as a gas?  If so, are the physics of compressing a gas the same as compressing a liquid?  Which is to say, do liquids obey Charles' and Boyle's Laws?  I cannot recall what I undoubtedly learned in college.