212edo: Difference between revisions

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{{Infobox ET}}
{{Infobox ET}}
{{EDO intro|212}}
{{ED intro}}


== Theory ==
== Theory ==
212edo is [[consistency|distinctly consistent]] in the [[15-odd-limit]] with [[harmonic]]s of 3 through 13 all tuned flat. It shares the [[3/1|3rd]], [[5/1|5th]], and [[13/1|13th]] [[harmonic]]s with [[53edo]], but the mapping differs for [[7/1|7]] and [[11/1|11]].  
212edo is [[consistency|distinctly consistent]] in the [[15-odd-limit]] with [[harmonic]]s of 3 through 13 all tuned flat. It shares the [[3/1|3rd]], [[5/1|5th]], and [[13/1|13th]] [[harmonic]]s with [[53edo]], but the mapping differs for [[7/1|7]] and [[11/1|11]].  


It [[tempers out]] the same commas ([[15625/15552]], [[32805/32768]], [[amity comma|1600000/1594323]], etc.) as 53edo in the [[5-limit]]. In the [[7-limit]], it tempers out 2401/2400 ([[breedsma]]), 390625/388962 ([[dimcomp comma]]), and 4802000/4782969 ([[canousma]]). In the [[11-limit]], [[385/384]], [[1375/1372]], [[6250/6237]], [[9801/9800]], and [[14641/14580]]; in the [[13-limit]], [[325/324]], [[625/624]], [[676/675]], [[1001/1000]], [[1716/1715]], [[2080/2079]], and [[10648/10647]].  
It [[tempering out|tempers out]] the same commas ([[15625/15552]], [[32805/32768]], [[amity comma|1600000/1594323]], etc.) as 53edo in the [[5-limit]]. In the [[7-limit]], it tempers out 2401/2400 ([[breedsma]]), 390625/388962 ([[dimcomp comma]]), and 4802000/4782969 ([[canousma]]). In the [[11-limit]], [[385/384]], [[1375/1372]], [[6250/6237]], [[9801/9800]], and [[14641/14580]]; in the [[13-limit]], [[325/324]], [[625/624]], [[676/675]], [[1001/1000]], [[1716/1715]], [[2080/2079]], and [[10648/10647]].  


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 beyond 15-odd-limit. 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.
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|columns=11}}
{{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 {{factorisation|212}}, 212edo has subset edos {{EDOs| 2, 4, 53, and 106 }}. As such, it can be used to tune the period-53 [[cartography]] temperament and the period-106 [[boiler]] temperment.  
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.
Line 33: Line 36:
| 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 }}
| {{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 }}
| {{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 }}
| {{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)
| {{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)
| {{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]].