212edo: Difference between revisions
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{{Infobox ET}} | {{Infobox ET}} | ||
{{ | {{ED intro}} | ||
== Theory == | == Theory == | ||
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It is the [[optimal patent val]] for 7- and 13-limit [[quadritikleismic]] temperament, the 7-limit [[Kleismic rank three family #Rank-3 kleismic|rank-3 kleismic]] temperament, and the 13-limit rank-3 [[agni]] temperament. It enables [[marveltwin chords]], [[keenanismic chords]], [[sinbadmic chords]], and [[lambeth chords]] in the 13-odd-limit in addition to [[island chords]] in the 15-odd-limit. | It is the [[optimal patent val]] for 7- and 13-limit [[quadritikleismic]] temperament, the 7-limit [[Kleismic rank three family #Rank-3 kleismic|rank-3 kleismic]] temperament, and the 13-limit rank-3 [[agni]] temperament. It enables [[marveltwin chords]], [[keenanismic chords]], [[sinbadmic chords]], and [[lambeth chords]] in the 13-odd-limit in addition to [[island chords]] in the 15-odd-limit. | ||
The 212gh val shows some potential | To the 13-limit we may add the [[prime harmonic|prime]] [[23/1|23]] without introducing too much extra error, tempering out [[484/483]] and [[507/506]]. The 212gh val shows some potential if the full [[23-limit]] is desired, where it notably tempers out [[289/288]] and [[361/360]]. Also, using 212bb val (where fifth is flattened by single step, approximately 1/4 comma) gives a tuning almost identical to the POTE tuning for 5-limit meantone. This is related to the fact that 212edo splits steps of 53edo, which are mapped to a syntonic comma, in four. | ||
=== Prime harmonics === | === Prime harmonics === | ||
{{Harmonics in equal|212}} | {{Harmonics in equal|212}} | ||
=== Octave stretch === | |||
212edo can benefit from slightly [[stretched and compressed tuning|stretching the octave]], using tunings such as [[124edf]] or [[336edt]]. This improves the approximated harmonics 5, 7, 11, 13 and brings the flat mappings of 17 and 19 closer; only the 23 becomes less accurate as it is tuned sharp already. | |||
=== Subsets and supersets === | === Subsets and supersets === | ||
Since 212 factors into {{ | Since 212 factors into primes as {{nowrap| 2<sup>2</sup> × 53 }}, 212edo has subset edos {{EDOs| 2, 4, 53, and 106 }}. As such, it can be used to tune the 53rd-octave [[cartography]] temperament and the 106th-octave [[boiler]] temperment. | ||
A step of 212edo is exactly 50 [[türk sent]]s. | A step of 212edo is exactly 50 [[türk sent]]s. | ||
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| 2.3.5.7 | | 2.3.5.7 | ||
| 2401/2400, 15625/15552, 32805/32768 | | 2401/2400, 15625/15552, 32805/32768 | ||
| {{ | | {{Mapping| 212 336 492 595 }} | ||
| +0.243 | | +0.243 | ||
| 0.244 | | 0.244 | ||
Line 40: | Line 43: | ||
| 2.3.5.7.11 | | 2.3.5.7.11 | ||
| 385/384, 1375/1372, 6250/6237, 14641/14580 | | 385/384, 1375/1372, 6250/6237, 14641/14580 | ||
| {{ | | {{Mapping| 212 336 492 595 733 }} | ||
| +0.325 | | +0.325 | ||
| 0.273 | | 0.273 | ||
Line 47: | Line 50: | ||
| 2.3.5.7.11.13 | | 2.3.5.7.11.13 | ||
| 325/324, 385/384, 625/624, 1375/1372, 10648/10647 | | 325/324, 385/384, 625/624, 1375/1372, 10648/10647 | ||
| {{ | | {{Mapping| 212 336 492 595 733 784 }} | ||
| +0.396 | | +0.396 | ||
| 0.296 | | 0.296 | ||
Line 54: | Line 57: | ||
| 2.3.5.7.11.13.17 | | 2.3.5.7.11.13.17 | ||
| 289/288, 325/324, 385/384, 442/441, 625/624, 10648/10647 | | 289/288, 325/324, 385/384, 442/441, 625/624, 10648/10647 | ||
| {{ | | {{Mapping| 212 336 492 595 733 784 866 }} (212g) | ||
| +0.447 | | +0.447 | ||
| 0.301 | | 0.301 | ||
Line 61: | Line 64: | ||
| 2.3.5.7.11.13.17.19 | | 2.3.5.7.11.13.17.19 | ||
| 289/288, 325/324, 361/360, 385/384, 442/441, 513/512, 625/624 | | 289/288, 325/324, 361/360, 385/384, 442/441, 513/512, 625/624 | ||
| {{ | | {{Mapping| 212 336 492 595 733 784 866 900 }} (212gh) | ||
| +0.485 | | +0.485 | ||
| 0.299 | | 0.299 | ||
| 5.27 | | 5.27 | ||
|- | |||
| 2.3.5.7.11.13.17.19.23 | |||
| 289/288, 323/322, 325/324, 361/360, 385/384, 442/441, 484/483, 507/506 | |||
| {{Mapping| 212 336 492 595 733 784 866 900 959 }} (212gh) | |||
| +0.430 | |||
| 0.321 | |||
| 5.67 | |||
|} | |} | ||
* 212et (212gh val) has a lower absolute error in the 19-limit than any previous equal temperaments, past [[193edo|193]] and followed by [[217edo|217]]. | * 212et (212gh val) has a lower absolute error in the 19-limit than any previous equal temperaments, past [[193edo|193]] and followed by [[217edo|217]]. |