3ed11/9
| ← 2ed11/9 | 3ed11/9 | 4ed11/9 → |
(semiconvergent)
(semiconvergent)
3 equal divisions of 11/9 (abbreviated 3ed11/9) is a nonoctave tuning system that divides the interval of 11/9 into 3 equal parts of about 116 ¢ each. Each step represents a frequency ratio of (11/9)1/3, or the cube root of 11/9.
11 steps of this temperament is an extremely close approximation of 92:132, having only 0.5% relative error. 6 steps is exactly 92:112 (since 3 steps is 9:11), so 92:112:132 (81:121:169) is well approximated, which represents the approximate 2:3:4 created by overtones of chimes.[1]
92:112:132:172:232 is also very well approximated, as is 152:192:212.
Approximation of odd square harmonics relative to 92
ratio | steps | relative error | absolute error
12:92 | -66 | -30.4% | -35.2¢
32:92 | -33 | -15.2% | -17.6¢
52:92 | -18 | -42.5% | -49.3¢
72:92 | -8 | -48.6% | -56.3¢
92:92 | 0 | 0% | 0¢
112:92 | 6 | 0% | 0¢
132:92 | 11 | -0.51% | -0.59¢
152:92 | 15 | -27.4% | -32.1¢
172:92 | 19 | -1.6% | -1.8¢
192:92 | 22 | -34.2% | -39.5¢
212:92 | 25 | -33.4% | -38.7¢
232:92 | 28 | -5.4% | -6.3¢
9ed11/9 is a possible correction for 15, 19, and 21.