9ed5/2
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| ← 8ed5/2 | 9ed5/2 | 10ed5/2 → |
(semiconvergent)
9 equal divisions of 5/2 (abbreviated 9ed5/2) is a nonoctave tuning system that divides the interval of 5/2 into 9 equal parts of about 176 ¢ each. Each step represents a frequency ratio of (5/2)1/9, or the 9th root of 5/2.
Theory
9ed5/2 can function as a generator chain for the tetracot temperament.
Harmonics
| Harmonic | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | +33.8 | +36.9 | +67.6 | +33.8 | +70.7 | -19.9 | -74.9 | +73.7 | +67.6 | +78.9 | -71.8 |
| Relative (%) | +19.2 | +20.9 | +38.4 | +19.2 | +40.1 | -11.3 | -42.5 | +41.8 | +38.4 | +44.7 | -40.7 | |
| Steps (reduced) |
7 (7) |
11 (2) |
14 (5) |
16 (7) |
18 (0) |
19 (1) |
20 (2) |
22 (4) |
23 (5) |
24 (6) |
24 (6) | |
| Harmonic | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | -34.1 | +13.9 | +70.7 | -41.1 | +30.2 | -68.7 | +13.9 | -74.9 | +16.9 | -63.6 | +35.7 | -38.0 |
| Relative (%) | -19.3 | +7.9 | +40.1 | -23.3 | +17.2 | -39.0 | +7.9 | -42.5 | +9.6 | -36.1 | +20.3 | -21.6 | |
| Steps (reduced) |
25 (7) |
26 (8) |
27 (0) |
27 (0) |
28 (1) |
28 (1) |
29 (2) |
29 (2) |
30 (3) |
30 (3) |
31 (4) |
31 (4) | |
Intervals
| # | Cents | Approximated ratios |
|---|---|---|
| 0 | 0 | 1/1 |
| 1 | 176 | 10/9, 11/10, 21/19 |
| 2 | 353 | 11/9, 16/13 |
| 3 | 529 | 15/11, 19/14, 27/20 |
| 4 | 705 | 3/2 |
| 5 | 881 | 5/3 |
| 6 | 1058 | 11/6, 24/13 |
| 7 | 1234 | 45/22 |
| 8 | 1410 | 9/4 |
| 9 | 1586 | 5/2 |