Class, come to order! As much as I dislike being contradictory seismic noise actually encompasses all of the various types of very low frequency, low frequency and higher frequency vibration that can be transmitted via the floor or any other building structure.
Thus, seismic noise producers include - but are not lmited to - earth crust motion, other earth vibration, wind, footfall, traffic, subway, ocean wave action, local construction, large fans and speaker feedback. Thus, seismic frequencies should be considered to be primarily in the range 0 Hz to 30 Hz but extending also to higher frequencies. Which is why the Townshend isolation data showed 88% and 97% or whatever isolation effectiveness at 20 Hz and higher frequencies like 150 Hz. Hel-loo!
Thus, seismic noise producers include - but are not lmited to - earth crust motion, other earth vibration, wind, footfall, traffic, subway, ocean wave action, local construction, large fans and speaker feedback. Thus, seismic frequencies should be considered to be primarily in the range 0 Hz to 30 Hz but extending also to higher frequencies. Which is why the Townshend isolation data showed 88% and 97% or whatever isolation effectiveness at 20 Hz and higher frequencies like 150 Hz. Hel-loo!