Interesting. Shades of the old DBX 100 sub-harmonic synthesizer...Interestingly, the bass note here is 65.3 Hz. Divide that by 2 and you get 32.65 Hz.
That raises an interesting question: Was there a bass pedal track on the master tape that was never used before? Or did Mr. Guthrie use a bass extension plugin during the remix to add those notes in an octave lower?