Scaling Rules for Organ Flue Pipe Ranks

The scaling problems involved in designing a rank of organ flue pipes which is satisfactorily coherent in tonal balance and matched in loudness level are investigated from the viewpoint of acoustical theory. The suggested solution from the viewpoint of tonal balance, that the pipe diameter should vary as the 5/6 power of pipe length, leads to a rank which is too loud in the bass. The usual practical solution, which is to make the diameter vary as the 3/4 power of length and to make further voicing adjustments, is seen to give an approximately balanced loudness and an increase in harmonic development towards the bass of the rank. Such a solution is similar in effect to that adopted for other musical instruments.