197ed12: Difference between revisions

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{{Infobox ET}}
{{Infobox ET}}
'''[[Ed12|Division of the twelfth harmonic]] into 197 equal parts''' (197ED12) is very nearly identical to [[55edo|55 EDO]], but with the [[12/1]] rather than the 2/1 being just. The octave is about 1.05 [[cent]]s stretched and the step size is about 21.84 cents.
{{ED intro}}


== Theory ==
== Theory ==
This tuning tempers out [[81/80]] in the 5-limit; [[121/120]] in the 11-limit; 91/90 and 169/168 in the 13-limit; and 154/153 in the 17-limit.
This tuning serves as a stretched version of [[55edo]], improving the accuracy of primes [[3/1|3]], [[7/1|7]], and [[11/1|11]], though prime [[5/1|5]] becomes worse. The [[patent val]]s match through the [[11-limit]], with the [[13-limit]] corresponding to the 55f [[val]] (written with [[wart notation]]). It thus tempers out the same [[comma]]s as 55edo in the 11-limit, and the same commas as 55f in the [[13-limit]].


==Harmonics==
== Harmonics ==
{{Harmonics in equal|197|12|1|prec=2|columns=11}}
{{Harmonics in equal|197|12|1|prec=2|columns=11}}
{{Harmonics in equal|197|12|1|prec=2|columns=11|start=12}}
{{Harmonics in equal|197|12|1|prec=2|columns=11|start=12}}

Latest revision as of 18:02, 20 March 2026

← 196ed12 197ed12 198ed12 →
Prime factorization 197 (prime)
Step size 21.8373 ¢ 
Octave 55\197ed12 (1201.05 ¢)
Twelfth 87\197ed12 (1899.85 ¢)
Consistency limit 4
Distinct consistency limit 4

197 equal divisions of the 12th harmonic (abbreviated 197ed12) is a nonoctave tuning system that divides the interval of 12/1 into 197 equal parts of about 21.8 ¢ each. Each step represents a frequency ratio of 121/197, or the 197th root of 12.

Theory

This tuning serves as a stretched version of 55edo, improving the accuracy of primes 3, 7, and 11, though prime 5 becomes worse. The patent vals match through the 11-limit, with the 13-limit corresponding to the 55f val (written with wart notation). It thus tempers out the same commas as 55edo in the 11-limit, and the same commas as 55f in the 13-limit.

Harmonics

Approximation of harmonics in 197ed12
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +1.05 -2.11 +2.11 +8.87 -1.05 -5.88 +3.16 -4.21 +9.92 -2.22 +0.00
Relative (%) +4.8 -9.6 +9.6 +40.6 -4.8 -26.9 +14.5 -19.3 +45.4 -10.2 +0.0
Steps
(reduced)
55
(55)
87
(87)
110
(110)
128
(128)
142
(142)
154
(154)
165
(165)
174
(174)
183
(183)
190
(190)
197
(0)
Approximation of harmonics in 197ed12
Harmonic 13 14 15 16 17 18 19 20 21 22 23
Error Absolute (¢) -7.55 -4.82 +6.76 +4.21 +8.44 -3.16 -9.41 -10.87 -7.98 -1.17 +9.22
Relative (%) -34.6 -22.1 +30.9 +19.3 +38.7 -14.5 -43.1 -49.8 -36.6 -5.4 +42.2
Steps
(reduced)
203
(6)
209
(12)
215
(18)
220
(23)
225
(28)
229
(32)
233
(36)
237
(40)
241
(44)
245
(48)
249
(52)