31ed7/4

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← 30ed7/431ed7/432ed7/4 →
Prime factorization 31 (prime)
Step size 31.2524¢ 
Octave 38\31ed7/4 (1187.59¢)
Twelfth 61\31ed7/4 (1906.4¢)
Consistency limit 2
Distinct consistency limit 2

31 equal divisions of 7/4 (abbreviated 31ed7/4) is a nonoctave tuning system that divides the interval of 7/4 into 31 equal parts of about 31.3 ¢ each. Each step represents a frequency ratio of (7/4)1/31, or the 31st root of 7/4.

Intervals

Steps Cents Approximate Ratios
0 0 1/1
1 31.252
2 62.505 26/25
3 93.757 18/17, 19/18
4 125.01 14/13, 15/14
5 156.262 23/21
6 187.515 19/17
7 218.767 17/15, 25/22
8 250.02 15/13, 22/19
9 281.272 13/11, 27/23
10 312.524 6/5
11 343.777 11/9, 17/14
12 375.029 21/17
13 406.282 19/15
14 437.534 9/7, 22/17
15 468.787 17/13, 25/19
16 500.039
17 531.292 15/11, 19/14, 23/17
18 562.544 18/13, 25/18
19 593.797
20 625.049
21 656.301 19/13, 22/15
22 687.554
23 718.806
24 750.059 17/11
25 781.311 11/7
26 812.564
27 843.816 18/11
28 875.069 5/3
29 906.321 22/13
30 937.573 19/11
31 968.826

Harmonics

Approximation of harmonics in 31ed7/4
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) -12.4 +4.4 +6.4 -4.8 -8.0 +6.4 -6.0 +8.9 +14.0 +5.3 +10.9
Relative (%) -39.7 +14.2 +20.6 -15.5 -25.5 +20.6 -19.1 +28.4 +44.8 +16.8 +34.8
Steps
(reduced)
38
(7)
61
(30)
77
(15)
89
(27)
99
(6)
108
(15)
115
(22)
122
(29)
128
(4)
133
(9)
138
(14)
Approximation of harmonics in 31ed7/4
Harmonic 13 14 15 16 17 18 19 20 21 22 23
Error Absolute (¢) -2.7 -6.0 -0.4 +12.9 +1.7 -3.5 -3.4 +1.6 +10.9 -7.1 +9.7
Relative (%) -8.6 -19.1 -1.3 +41.2 +5.4 -11.3 -10.8 +5.1 +34.8 -22.9 +30.9
Steps
(reduced)
142
(18)
146
(22)
150
(26)
154
(30)
157
(2)
160
(5)
163
(8)
166
(11)
169
(14)
171
(16)
174
(19)