769edo

From Xenharmonic Wiki
Jump to navigation Jump to search
← 768edo 769edo 770edo →
Prime factorization 769 (prime)
Step size 1.56047¢ 
Fifth 450\769 (702.211¢)
Semitones (A1:m2) 74:57 (115.5¢ : 88.95¢)
Consistency limit 9
Distinct consistency limit 9

769 equal divisions of the octave (abbreviated 769edo or 769ed2), also called 769-tone equal temperament (769tet) or 769 equal temperament (769et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 769 equal parts of about 1.56 ¢ each. Each step represents a frequency ratio of 21/769, or the 769th root of 2.

Theory

769edo is consistent to the 9-odd-limit, despite of a large error in its harmonic 5. As an equal temperament, it tempers out 2401/2400, 359661568/358722675 and [8 14 -13 0 in the 7-limit.

Odd harmonics

Approximation of odd harmonics in 769edo
Harmonic 3 5 7 9 11 13 15 17 19 21 23
Error Absolute (¢) +0.256 +0.682 +0.225 +0.511 -0.473 +0.565 -0.622 -0.404 +0.536 +0.480 +0.594
Relative (%) +16.4 +43.7 +14.4 +32.8 -30.3 +36.2 -39.9 -25.9 +34.4 +30.8 +38.1
Steps
(reduced)
1219
(450)
1786
(248)
2159
(621)
2438
(131)
2660
(353)
2846
(539)
3004
(697)
3143
(67)
3267
(191)
3378
(302)
3479
(403)

Subsets and supersets

769edo is the 136th prime edo. 1538edo, which doubles it, gives a good correction to the harmonic 5.

Regular temperament properties

Subgroup Comma List Mapping Optimal
8ve Stretch (¢)
Tuning Error
Absolute (¢) Relative (%)
2.3 [1219 -769 [769 1219]] -0.0807 0.0806 5.17
2.3.5 [8 14 -13, [103 -43 -15 [769 1219 1786]] -0.1517 0.1202 7.70
2.3.5.7 2401/2400, 359661568/358722675, 1224440064/1220703125 [769 1219 1786 2159]] -0.1338 0.1086 6.96

Rank-2 temperaments

Table of rank-2 temperaments by generator
Periods
per 8ve
Generator* Cents* Associated
Ratio*
Temperaments
1 202\769 315.215 6/5 Parakleismic
1 220\769 343.303 8000/6561 Raider
1 225\769 351.105 49/40 Newt
1 334\769 521.196 875/648 Maviloid

* octave-reduced form, reduced to the first half-octave, and minimal form in parentheses if it is distinct