1984edo
| ← 1983edo | 1984edo | 1985edo → |
1984 equal divisions of the octave (abbreviated 1984edo or 1984ed2), also called 1984-tone equal temperament (1984tet) or 1984 equal temperament (1984et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 1984 equal parts of about 0.605 ¢ each. Each step represents a frequency ratio of 21/1984, or the 1984th root of 2.
1984edo is consistent in the 7-odd-limit and is a mostly sharp system, with 3, 5, 7, 11, and 17 all tuned sharp. Harmonics 9 and 15, though, are tuned flat, which results in inconsistencies, that is, their direct approximations are not the same as the sum of their constituent odd harmonics' direct approximations: 9/1 is 6289 steps while 3/1 is 3145 steps (and 3145 + 3145 = 6290, ≠ 6289), and 15/1 is 7751 steps while 5/1 is 4607 steps (and 3145 + 4607 = 7752, ≠ 7751). 1984edo does, however, approximate the 2.9.19.31.33 subgroup well.
In the 7-limit the equal temperament tempers out the wizma (420175/419904), the garischisma (33554432/33480783), and the pessoalisma (2147483648/2144153025).
Odd harmonics
| Harmonic | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 17 | 19 | 21 | 23 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | +0.263 | +0.178 | +0.126 | -0.079 | +0.295 | +0.198 | -0.164 | +0.287 | +0.068 | -0.216 | +0.153 |
| Relative (%) | +43.4 | +29.5 | +20.8 | -13.1 | +48.8 | +32.8 | -27.1 | +47.4 | +11.2 | -35.8 | +25.3 | |
| Steps (reduced) |
3145 (1161) |
4607 (639) |
5570 (1602) |
6289 (337) |
6864 (912) |
7342 (1390) |
7751 (1799) |
8110 (174) |
8428 (492) |
8714 (778) |
8975 (1039) | |
Subsets and supersets
Since 1984 factors into 26 × 31, 1984edo has subset edos 2, 4, 8, 16, 31, 32, 62, 64, 124, 248, 496, and 992.