684edo: Difference between revisions

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+infobox; +RTT table and rank-2 temperaments
Regular temperament properties: +semihemienneadecal
Line 55: Line 55:
| 1053/800<br>(1287/1280)
| 1053/800<br>(1287/1280)
| [[Semihemiennealimmal]]
| [[Semihemiennealimmal]]
|-
| 38
| 151\684<br>(7\684)
| 264.91<br>(12.28)
| 500/429<br>(144/143)
| [[Semihemienneadecal]]
|}
|}


[[Category:Equal divisions of the octave|###]] <!-- 3-digit number -->
[[Category:Equal divisions of the octave|###]] <!-- 3-digit number -->

Revision as of 00:06, 21 September 2022

← 683edo 684edo 685edo →
Prime factorization 22 × 32 × 19
Step size 1.75439 ¢ 
Fifth 400\684 (701.754 ¢) (→ 100\171)
Semitones (A1:m2) 64:52 (112.3 ¢ : 91.23 ¢)
Consistency limit 17
Distinct consistency limit 17

Template:EDO intro

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

Approximation of prime harmonics in 684edo
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)

Regular temperament properties

Subgroup Comma List Mapping Optimal
8ve stretch (¢)
Tuning error
Absolute (¢) Relative (%)
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, 1701/1700, 2025/2023, 2058/2057, 4225/4224, 13013/13005 [684 1084 1588 1920 2366 2531 2796]] +0.0744 0.0800 4.56
  • 684et is the first equal temperament with a lower 13-limit absolute error after 494. The next equal temperament that is better tuned is 764.

Rank-2 temperaments

Table of rank-2 temperaments by generator
Periods
per Octave
Generator
(Reduced)
Cents
(Reduced)
Associated
Ratio
Temperaments
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