Appendix E. Modal Frequency Ratios

Contributed by Scott Lindroth

John Bower, a student of Scott Lindroth, compiled this list of modal frequencies for various objects and materials. Some modes work better than others, and most need to be in a particular frequency range to sound plausible. Caveat emptor.

In general, wooden objects will not sound "wooden" unless a stochastic component is present in the sound (try banded waveguides). Nonetheless, some of the wooden objects make wonderful metallic instruments as well.

This ratios can be useful together with opcodes like mode or streson.

Table E.1. Modal Frequency Ratios

Instrument Modal Frequency Ratios
Dahina tabla [1, 2.89, 4.95, 6.99, 8.01, 9.02]
Bayan tabla [1, 2.0, 3.01, 4.01, 4.69, 5.63]
Red Cedar wood plate [1, 1.47, 2.09, 2.56]
Redwood wood plate [1, 1.47, 2.11, 2.57]
Douglas Fir wood plate [1, 1.42, 2.11, 2.47]
uniform wooden bar [1, 2.572, 4.644, 6.984, 9.723, 12]
uniform aluminum bar [1, 2.756, 5.423, 8.988, 13.448, 18.680]
Xylophone [1, 3.932, 9.538, 16.688, 24.566, 31.147]
Vibraphone 1 [1, 3.984, 10.668, 17.979, 23.679, 33.642]
Vibraphone 2 [1, 3.997, 9.469, 15.566, 20.863, 29.440]
Chalandi plates

([62, 107, 360, 460, 863] Hz +-2Hz)

[1, 1.72581, 5.80645, 7.41935, 13.91935] ratios

tibetan bowl (180mm)

( [221, 614, 1145, 1804, 2577, 3456, 4419] Hz) 934g, 180mm

[1, 2.77828, 5.18099, 8.16289, 11.66063, 15.63801, 19.99 ratios

tibetan bowl (152 mm)

([314, 836, 1519, 2360, 3341, 4462, 5696] Hz) 563g, 152mm

[1, 2.66242, 4.83757, 7.51592, 10.64012, 14.21019, 18.14027] ratios

tibetan bowl (140 mm)

([528, 1460, 2704, 4122, 5694] Hz) 557g, 140mm

[1, 2.76515, 5.12121, 7.80681, 10.78409] ratios

Wine Glass [1, 2.32, 4.25, 6.63, 9.38]
small handbell

([1312.0, 1314.5, 2353.3, 2362.9, 3306.5, 3309.4, 3923.8, 3928.2, 4966.6, 4993.7, 5994.4, 6003.0, 6598.9, 6619.7, 7971.7, 7753.2, 8413.1, 8453.3, 9292.4, 9305.2, 9602.3, 9912.4] Hz)

[ 1, 1.0019054878049, 1.7936737804878, 1.8009908536585, 2.5201981707317, 2.5224085365854, 2.9907012195122, 2.9940548780488, 3.7855182926829, 3.8061737804878, 4.5689024390244, 4.5754573170732, 5.0296493902439, 5.0455030487805, 6.0759908536585, 5.9094512195122, 6.4124237804878, 6.4430640243902, 7.0826219512195, 7.0923780487805, 7.3188262195122, 7.5551829268293 ] ratios

spinel sphere with diameter of 3.6675mm

([977.25, 1003.16, 1390.13, 1414.93, 1432.84, 1465.34, 1748.48, 1834.20, 1919.90, 1933.64, 1987.20, 2096.48, 2107.10, 2202.08, 2238.40, 2280.10, 0 /*2290.53 calculated*/, 2400.88, 2435.85, 2507.80, 2546.30, 2608.55, 2652.35, 2691.70, 2708.00] Hz)

[ 1, 1.026513174725, 1.4224916858532, 1.4478690202098, 1.4661959580455, 1.499452545408, 1.7891839345101, 1.8768994627782, 1.9645945254541, 1.9786543873113, 2.0334612432847, 2.1452852391916, 2.1561524686621, 2.2533435661294, 2.2905090816065, 2.3331798413917, 0, 2.4567715528268, 2.4925556408289, 2.5661806088514, 2.6055768738808, 2.6692760296751, 2.7140956766436, 2.7543617293425, 2.7710411870043 ] ratios

pot lid

[ 1, 3.2, 6.23, 6.27, 9.92, 14.15] ratios