Analyses of Tones of Wind Instruments and of Resonating Strings
Frank A. Saunders · The Journal of the Acoustical Society of America · 1944
In the course of studies of violins, it became of interest to find out how much their tone analyses differed from those of certain wind instruments. Analyses were made of flute, clarinet, oboe, English horn, and French horn, rather softly blown, over their whole range. The results show no such violent variations in volume of tone as in violins, though a weak spot appears in the oboe and the clarinet. For low tones in oboe, English horn, and French horn the upper partials are strongest. These die off progressively on the way up the scale until at the top the order of prominence is the order of the partials, as in high violin tones. The order of appearance of the even-numbered partials in the clarinet is interesting; 6, 4, and 2 are absent in the lowest tones, and they appear progressively, in that order. The second passes the third one octave below the top; the fundamental is nearly always loudest. The violin family includes the viola d'amore, in which seven or more extra wires which are not fingered are added for resonance. Some writers and many musicians believe that the extra wires increase the loudness, though wires were once supposed to kill the sound in an auditorium. To test the matter, analyses were made of A-440 tones from each of two violins played on the D string, with or without allowing the open A string to resonate. The results show no effect unless the tuning is exact, but clearly show that the resonating string weakens the output of the fundamental without appreciably affecting the upper partials. If the energy supply given to the bowed string is constant, it is clear that the roundabout process of producing sound from the violin box by way of the resonating string must involve a loss of energy. The peculiar quality of the viola d'amore, if it exists, must be due to some cause other than the presence of the extra wires.