Unfortunately it’s not really a question of "microphonic immunity." There is nothing you can do to make a component - any component - immune to low frequency seismic type vibration, I mean other than isolate it from those vibrations using some type of low pass mechanical filter. That’s because the entire building is shaking, so anything connected to it is shaking right along with it.
Obviously some steps can be talken (but usually aren’t) inside the component to guard against vibration with higher frequencies, you know, using damping techniques,including those produced by the component itself such as transformer hum, CD transport mechanical noise, motor noise, etc.