geoffkait:
If tonearms and cartridges are engineered to have resonant frequencies circa 10-12 Hz, then it's absolutely illogical to conclude that isolating the turntable from seismic frequencies will reduce vibration of the tonearm and cartridge. Whatever hocus-pocus you apply to your turntable, you won't alter the resonant frequency of the tonearm and cartridge.
Good rule of thumb: Don't listen to your vinyl during an earthquake.
If tonearms and cartridges are engineered to have resonant frequencies circa 10-12 Hz, then it's absolutely illogical to conclude that isolating the turntable from seismic frequencies will reduce vibration of the tonearm and cartridge. Whatever hocus-pocus you apply to your turntable, you won't alter the resonant frequency of the tonearm and cartridge.
Good rule of thumb: Don't listen to your vinyl during an earthquake.