The Gentle Giant

The 32 ft. open wood pipe produces an effect of which the King of Instruments alone may boast. It cannot be reproduced by any other means, as far as I am aware, save that of a wood or metal pipe thirty-two feet long and of adequate scale. Not even the diaphone can produce the characteristic "seething, bubbling" effect of the traditional pedal pipe. Any attempt at imitation by means of an oscillating valve or any other electronic system must inevitably fail owing to the sheer incapability of a loudspeaker diaphragm to handle such a sound wave without "frequency doubling." There is no acoustic system of tone-production that can vie with the aerial mechanism of a 32 ft. pipe of wood measuring, say, 29 in. by 25 in. at CCCC (the scale adopted by Mr. Willis at Liverpool Cathedral). True, the actual fundamental frequency of sixteen vibrations per second cannot be distinguished by human ears : the lowest frequency in the audible range is twenty vibrations per second. But it does not follow that the sound emitted by the CCCC pipe is lost on the listener : far from it ! It has a psychological effect on the listener that no other sound is able to produce, and only a 32 ft. flue pipe
can do it.

Quoted from "The Modern British Organ" by Noel A. Bonavia-Hunt, M. A.