618edo: Difference between revisions

From Xenharmonic Wiki
Jump to navigation Jump to search
BudjarnLambeth (talk | contribs)
mNo edit summary
Rework; cleanup; +subsets and supersets; -redundant categories
Line 2: Line 2:
{{EDO intro|618}}
{{EDO intro|618}}


== Theory ==
618edo is [[consistent]] to the [[7-odd-limit]], but [[harmonic]] [[3/1|3]] is about halfway between its steps. Nonetheless, as every other step of [[1236edo]], 618edo is excellent in approximating harmonics [[5/1|5]], [[7/1|7]], [[9/1|9]], [[11/1|11]], [[13/1|13]], and [[17/1|17]], making it suitable for a 2.9.5.7.11.13.17 [[subgroup]] interpretation, where the equal temperament notably [[tempering out|tempers out]] [[2601/2600]], [[4096/4095]], [[5832/5831]], [[6656/6655]], [[9801/9800]], and [[10648/10647]]. With a reasonable approximation of 19, it further tempers out 2926/2925, 5985/5984, and 6175/6174.  
As every other step of [[1236edo]], 618edo is excellent in the 2.9.5.7.11.13.17 subgroup, where it notably tempers out [[2601/2600]], [[4096/4095]], [[5832/5831]], [[6656/6655]], [[9801/9800]], and [[10648/10647]]. With a reasonable approximation of 19, it further tempers out 2926/2925, 5985/5984, and 6175/6174.  


=== Odd harmonics ===
=== Odd harmonics ===
{{Harmonics in equal|618}}
{{Harmonics in equal|618}}


[[Category:Equal divisions of the octave|###]] <!-- 3-digit number -->
=== Subsets and supersets ===
Since 618 factors into 2 × 3 × 103, 618edo has subset edos {{EDOs| 2, 3, 6, 103, 206, and 309 }}. 1236edo, which doubles it, provides a good correction for harmonic 3.

Revision as of 08:11, 25 October 2023

← 617edo 618edo 619edo →
Prime factorization 2 × 3 × 103
Step size 1.94175 ¢ 
Fifth 362\618 (702.913 ¢) (→ 181\309)
Semitones (A1:m2) 62:44 (120.4 ¢ : 85.44 ¢)
Dual sharp fifth 362\618 (702.913 ¢) (→ 181\309)
Dual flat fifth 361\618 (700.971 ¢)
Dual major 2nd 105\618 (203.883 ¢) (→ 35\206)
Consistency limit 7
Distinct consistency limit 7

Template:EDO intro

618edo is consistent to the 7-odd-limit, but harmonic 3 is about halfway between its steps. Nonetheless, as every other step of 1236edo, 618edo is excellent in approximating harmonics 5, 7, 9, 11, 13, and 17, making it suitable for a 2.9.5.7.11.13.17 subgroup interpretation, where the equal temperament notably tempers out 2601/2600, 4096/4095, 5832/5831, 6656/6655, 9801/9800, and 10648/10647. With a reasonable approximation of 19, it further tempers out 2926/2925, 5985/5984, and 6175/6174.

Odd harmonics

Approximation of odd harmonics in 618edo
Harmonic 3 5 7 9 11 13 15 17 19 21 23
Error Absolute (¢) +0.958 +0.094 +0.106 -0.027 +0.138 +0.249 -0.890 -0.101 -0.426 -0.878 +0.852
Relative (%) +49.3 +4.8 +5.5 -1.4 +7.1 +12.8 -45.8 -5.2 -21.9 -45.2 +43.9
Steps
(reduced)
980
(362)
1435
(199)
1735
(499)
1959
(105)
2138
(284)
2287
(433)
2414
(560)
2526
(54)
2625
(153)
2714
(242)
2796
(324)

Subsets and supersets

Since 618 factors into 2 × 3 × 103, 618edo has subset edos 2, 3, 6, 103, 206, and 309. 1236edo, which doubles it, provides a good correction for harmonic 3.