81edt

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← 80edt 81edt 82edt →
Prime factorization 34
Step size 23.4809¢ 
Octave 51\81edt (1197.53¢) (→17\27edt)
Consistency limit 4
Distinct consistency limit 4

81 equal divisions of the tritave, perfect twelfth, or 3rd harmonic (abbreviated 81edt or 81ed3), is a nonoctave tuning system that divides the interval of 3/1 into 81 equal parts of about 23.5⁠ ⁠¢ each. Each step represents a frequency ratio of 31/81, or the 81st root of 3.

Intervals

Steps Cents Hekts Approximate ratios
0 0 0 1/1
1 23.5 16
2 47 32.1 36/35, 37/36, 38/37, 39/38, 40/39
3 70.4 48.1
4 93.9 64.2 19/18, 37/35, 39/37
5 117.4 80.2 31/29
6 140.9 96.3 13/12, 38/35
7 164.4 112.3 11/10
8 187.8 128.4 29/26, 39/35
9 211.3 144.4 26/23, 35/31
10 234.8 160.5 39/34
11 258.3 176.5 36/31
12 281.8 192.6 20/17
13 305.3 208.6 31/26, 37/31
14 328.7 224.7 23/19, 29/24, 35/29
15 352.2 240.7 27/22, 38/31
16 375.7 256.8 36/29
17 399.2 272.8 29/23, 34/27, 39/31
18 422.7 288.9 23/18, 37/29
19 446.1 304.9 22/17, 31/24, 35/27
20 469.6 321 21/16, 38/29
21 493.1 337
22 516.6 353.1 27/20, 31/23, 35/26
23 540.1 369.1 15/11, 26/19
24 563.5 385.2 18/13
25 587 401.2
26 610.5 417.3 27/19, 37/26
27 634 433.3 13/9
28 657.5 449.4 19/13
29 680.9 465.4 40/27
30 704.4 481.5 3/2
31 727.9 497.5 32/21, 35/23
32 751.4 513.6 17/11, 37/24
33 774.9 529.6 36/23
34 798.4 545.7 19/12, 27/17
35 821.8 561.7 37/23
36 845.3 577.8 31/19
37 868.8 593.8 33/20, 38/23
38 892.3 609.9
39 915.8 625.9 17/10, 39/23
40 939.2 642 31/18
41 962.7 658
42 986.2 674.1 23/13, 30/17
43 1009.7 690.1 34/19
44 1033.2 706.2 20/11
45 1056.6 722.2 35/19
46 1080.1 738.3
47 1103.6 754.3 17/9, 36/19
48 1127.1 770.4 23/12
49 1150.6 786.4 33/17, 35/18
50 1174 802.5
51 1197.5 818.5 2/1
52 1221 834.6
53 1244.5 850.6 37/18, 39/19
54 1268 866.7 27/13
55 1291.5 882.7 19/9, 40/19
56 1314.9 898.8
57 1338.4 914.8 13/6
58 1361.9 930.9 11/5
59 1385.4 946.9 20/9
60 1408.9 963
61 1432.3 979 16/7
62 1455.8 995.1
63 1479.3 1011.1 40/17
64 1502.8 1027.2 31/13
65 1526.3 1043.2 29/12
66 1549.7 1059.3 22/9
67 1573.2 1075.3
68 1596.7 1091.4
69 1620.2 1107.4
70 1643.7 1123.5 31/12
71 1667.1 1139.5 34/13
72 1690.6 1155.6
73 1714.1 1171.6 35/13
74 1737.6 1187.7 30/11
75 1761.1 1203.7 36/13
76 1784.6 1219.8
77 1808 1235.8 37/13
78 1831.5 1251.9
79 1855 1267.9 35/12, 38/13
80 1878.5 1284
81 1902 1300 3/1

Harmonics

Approximation of harmonics in 81edt
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) -2.5 +0.0 -4.9 +7.9 -2.5 -11.1 -7.4 +0.0 +5.4 +4.8 -4.9
Relative (%) -10.5 +0.0 -21.1 +33.7 -10.5 -47.1 -31.6 +0.0 +23.2 +20.5 -21.1
Steps
(reduced)
51
(51)
81
(0)
102
(21)
119
(38)
132
(51)
143
(62)
153
(72)
162
(0)
170
(8)
177
(15)
183
(21)
Approximation of harmonics in 81edt
Harmonic 13 14 15 16 17 18 19 20 21 22 23
Error Absolute (¢) -2.6 +10.0 +7.9 -9.9 +2.6 -2.5 -2.2 +3.0 -11.1 +2.3 -4.2
Relative (%) -11.2 +42.4 +33.7 -42.1 +10.9 -10.5 -9.2 +12.7 -47.1 +9.9 -17.8
Steps
(reduced)
189
(27)
195
(33)
200
(38)
204
(42)
209
(47)
213
(51)
217
(55)
221
(59)
224
(62)
228
(66)
231
(69)