An excellent organ recording. The Henry Willis organ was completed in 1926. It was considered then as the largest and most complete organ in the world. It features 146 speaking stops and several 32 foot pipes, as well as one resultant 64 foot bass stop. The resultant 64' pitch is designed as explained here:
When pure tones (sine waves) are sounded together, they combine to produce two additional tones whose frequencies are the sum and difference of the two original tones. For example, if the original frequencies are 32hz and 48hz, the resultant frequencies will be 80hz and 16 hz. While this effect occurs at all frequencies, it is most effective to the human ear at low frequencies. (This same acoustical principle is used by
celestes to produce a different effect.) This effect was discovered by Tartini around 1714 and by Sorge in 1740.
These stops use this acoustical effect to produce tones in the 32' and 64' octaves, using smaller (and thus less costly) pipes than would normally be necessary. One of these stops, labeled as 32' or 64' pitch, is comprised of two ranks which sound the 1st and 2nd harmonics of the desired pitch (that is, an octave and a twelfth above the desired pitch). For a 32' stop, the two ranks are 16' and 10-2/3'; for a 64' stop, the two ranks are 32' and 21-1/3'. This effect was first used in the organ by Abt Vogler (1749-1814). The first 64' resultant stops were probably introduced in the late 19th century. Some builders have experimented with using resultant tones in the 16' octave, but it is not an effective replacement for a true 16' stop.
If you want your sub(s) to move, this is one good recording of French organ music. It has to be played at higher than usual SPL in order to enjoy its possibilities.
