161edo: Difference between revisions
Wikispaces>genewardsmith **Imported revision 537229624 - Original comment: ** |
inconsistencies in 25-odd-limit |
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{{Infobox ET}} | |||
{{ED intro}} | |||
== Theory == | |||
161edo has a [[perfect fifth]] slightly sharp of that of [[12edo]], such that it maps the [[Pythagorean comma]] to one step. It approximates many of the low primes fairly well; however, it is only consistent to the [[7-odd-limit]], due to [[10/9]] being mapped too sharply from prime [[5/1|5]] being sharp, while [[3/1|3]] is flat. Nonetheless it does well for its size in higher limits, with the inconsistent intervals in the [[23-odd-limit]] being 9/5, [[13/9]], [[23/13]], and their [[octave complement]]s, and additional inconsistencies in the [[25-odd-limit]] include [[25/18]], [[25/23]], and their octave complements. Prime [[29/1|29]] is also accurate, though harmonic [[27/1|27]] is mapped inconsistently flat, causing many of its intervals to be inconsistent. Additionally, the flatness of 27 causes [[28/27]] to be mapped wider than [[27/26]], meaning 161edo is at most [[diamond monotone]] in the 25-odd-limit. | |||
As an equal temperament, 161et [[tempering out|tempers out]] the [[würschmidt comma]], 393216/390625, in the [[5-limit]]; [[3136/3125]], [[6144/6125]] and [[2401/2400]] in the [[7-limit]]; [[243/242]], [[441/440]], [[540/539]] and [[5632/5625]] in the [[11-limit]]; and [[351/350]], [[847/845]], [[1001/1000]], [[1188/1183]], [[1575/1573]] and [[1716/1715]] in the [[13-limit]]. It serves as the [[optimal patent val]] for the [[mintone]] temperament in the 5-, 7-, 11- and 13-limit. | |||
=== Prime harmonics === | |||
{{Harmonics in equal|161}} | |||
=== Subsets and supersets === | |||
Since 161 factors into 7 × 23, 161edo contains [[7edo]] and [[23edo]] as its subsets. | |||
== Intervals == | |||
{{Interval table}} | |||
== Regular temperament properties == | |||
{| class="wikitable center-4 center-5 center-6" | |||
|- | |||
! rowspan="2" | [[Subgroup]] | |||
! rowspan="2" | [[Comma list]] | |||
! rowspan="2" | [[Mapping]] | |||
! rowspan="2" | Optimal<br />8ve stretch (¢) | |||
! colspan="2" | Tuning error | |||
|- | |||
! [[TE error|Absolute]] (¢) | |||
! [[TE simple badness|Relative]] (%) | |||
|- | |||
| 2.3 | |||
| {{monzo| -255 161 }} | |||
| {{mapping| 161 255 }} | |||
| +0.421 | |||
| 0.421 | |||
| 5.65 | |||
|- | |||
| 2.3.5 | |||
| 393216/390625, {{monzo| -17 21 -7 }} | |||
| {{mapping| 161 255 374 }} | |||
| +0.099 | |||
| 0.570 | |||
| 7.65 | |||
|- | |||
| 2.3.5.7 | |||
| 2401/2400, 3136/3125, 177147/175000 | |||
| {{mapping| 161 255 374 452 }} | |||
| +0.064 | |||
| 0.498 | |||
| 6.67 | |||
|- | |||
| 2.3.5.7.11 | |||
| 243/242, 441/440, 3136/3125, 35937/35840 | |||
| {{mapping| 161 255 374 452 557 }} | |||
| +0.037 | |||
| 0.448 | |||
| 6.01 | |||
|- | |||
| 2.3.5.7.11.13 | |||
| 243/242, 351/350, 441/440, 847/845, 3136/3125 | |||
| {{mapping| 161 255 374 452 557 596 }} | |||
| −0.046 | |||
| 0.449 | |||
| 6.03 | |||
|- | |||
| 2.3.5.7.11.13.17 | |||
| 243/242, 351/350, 441/440, 561/560, 847/845, 1089/1088 | |||
| {{mapping| 161 255 374 452 557 596 658 }} | |||
| −0.018 | |||
| 0.422 | |||
| 5.66 | |||
|- | |||
| 2.3.5.7.11.13.17.19 | |||
| 243/242, 324/323, 351/350, 441/440, 456/455, 495/494, 513/512 | |||
| {{mapping| 161 255 374 452 557 596 658 684 }} | |||
| −0.034 | |||
| 0.397 | |||
| 5.32 | |||
|} | |||
* 161et has a lower [[TE error|absolute error]] than any previous equal temperaments in the 19-limit, even though it is inconsistent in the corresponding odd limit. The same subgroup is only better tuned by [[183edo]]. | |||
=== Rank-2 temperaments === | |||
{| class="wikitable center-all left-5" | |||
|+ style="font-size: 105%;" | Table of rank-2 temperaments by generator | |||
|- | |||
! Periods<br />per 8ve | |||
! Generator* | |||
! Cents* | |||
! Associated<br />ratio* | |||
! Temperaments | |||
|- | |||
| 1 | |||
| 15\161 | |||
| 111.80 | |||
| 16/15 | |||
| [[Vavoom]] | |||
|- | |||
| 1 | |||
| 16\161 | |||
| 119.25 | |||
| 15/14 | |||
| [[Septidiasemi]] | |||
|- | |||
| 1 | |||
| 17\161 | |||
| 126.71 | |||
| 14/13 | |||
| [[Mowglic]] | |||
|- | |||
| 1 | |||
| 25\161 | |||
| 186.34 | |||
| 10/9 | |||
| [[Mintone]] | |||
|- | |||
| 1 | |||
| 26\161 | |||
| 193.79 | |||
| 28/25 | |||
| [[Hemiwürschmidt]] | |||
|- | |||
| 1 | |||
| 38\161 | |||
| 283.23 | |||
| 33/28 | |||
| [[Neominor]] (161f) | |||
|- | |||
| 1 | |||
| 52\161 | |||
| 387.58 | |||
| 5/4 | |||
| [[Würschmidt]] (5-limit) | |||
|- | |||
| 1 | |||
| 79\161 | |||
| 588.82 | |||
| 45/32 | |||
| [[Aufo]] | |||
|- | |||
| 7 | |||
| 67\161<br />(2\161) | |||
| 499.38<br />(14.91) | |||
| 4/3<br />(81/80) | |||
| [[Absurdity]] | |||
|} | |||
<nowiki />* [[Normal forms #Equave-reduced-generator form|Octave-reduced form]], reduced to the first half-octave, and [[normal forms #Minimal-generator form|minimal form]] in parentheses if distinct | |||
[[Category:Mintone]] | |||