684edo
Theory
684edo divides the steps of 171edo into four. It is consistent to the 17-odd-limit, tempering out 2401/2400, 3025/3024, 4225/4224, 4375/4374, and 32805/32768 in the 13-limit; 1089/1088, 1225/1224, 1701/1700, 2025/2023, 2058/2057, 2500/2499, 8624/8619, and 14875/14872 in the 17-limit.
Prime harmonics
| Harmonic | 2 | 3 | 5 | 7 | 11 | 13 | 17 | 19 | 23 | 29 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | +0.000 | -0.201 | -0.349 | -0.405 | -0.441 | -0.177 | +0.308 | +0.733 | -0.204 | +0.247 | +0.578 |
| Relative (%) | +0.0 | -11.4 | -19.9 | -23.1 | -25.1 | -10.1 | +17.5 | +41.8 | -11.6 | +14.1 | +33.0 | |
| Steps (reduced) |
684 (0) |
1084 (400) |
1588 (220) |
1920 (552) |
2366 (314) |
2531 (479) |
2796 (60) |
2906 (170) |
3094 (358) |
3323 (587) |
3389 (653) | |
Subsets and supersets
Since 684 factors into 22 × 32 × 19, 684edo has subset edos 2, 3, 4, 6, 9, 12, 18, 19, 36, 38, 57, 76, 114, 171, 228, and 342.
Regular temperament properties
Template:Comma basis begin |- | 2.3.5.7.11.13 | 2401/2400, 3025/3024, 4225/4224, 4375/4374, 32805/32768 | [⟨684 1084 1588 1920 2366 2531]] | +0.0994 | 0.0558 | 3.18 |- | 2.3.5.7.11.13.17 | 1089/1088, 1225/1224, 1701/1700, 2025/2023, 4225/4224, 13013/13005 | [⟨684 1084 1588 1920 2366 2531 2796]] | +0.0744 | 0.0800 | 4.56 Template:Comma basis end
- 684et is the first equal temperament past 494 with a lower 13-limit absolute error. The next equal temperament that is better tuned is 764.
Rank-2 temperaments
Note: 11-limit temperaments supported by 342et are not shown.
Template:Rank-2 begin
|-
| 18
| 271\684
(5\684)
| 475.44
(8.77)
| 1053/800
(1287/1280)
| Semihemiennealimmal
|-
| 38
| 151\684
(7\684)
| 264.91
(12.28)
| 500/429
(144/143)
| Semihemienneadecal
Template:Rank-2 end
Template:Orf