161edo: Difference between revisions
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{{Infobox ET | {{Infobox ET}} | ||
{{ED intro}} | |||
}} | |||
== Theory == | == Theory == | ||
161edo tempers out the [[ | 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 === | === Prime harmonics === | ||
{{Harmonics in equal|161}} | {{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 == | == Regular temperament properties == | ||
{| class="wikitable center-4 center-5 center-6" | {| class="wikitable center-4 center-5 center-6" | ||
! rowspan="2" | Subgroup | |- | ||
! rowspan="2" | [[Subgroup]] | |||
! rowspan="2" | [[Comma list]] | ! rowspan="2" | [[Comma list]] | ||
! rowspan="2" | [[Mapping]] | ! rowspan="2" | [[Mapping]] | ||
! rowspan="2" | Optimal<br>8ve stretch (¢) | ! rowspan="2" | Optimal<br />8ve stretch (¢) | ||
! colspan="2" | Tuning error | ! colspan="2" | Tuning error | ||
|- | |- | ||
| Line 28: | Line 31: | ||
| 2.3 | | 2.3 | ||
| {{monzo| -255 161 }} | | {{monzo| -255 161 }} | ||
| | | {{mapping| 161 255 }} | ||
| +0.421 | | +0.421 | ||
| 0.421 | | 0.421 | ||
| Line 35: | Line 38: | ||
| 2.3.5 | | 2.3.5 | ||
| 393216/390625, {{monzo| -17 21 -7 }} | | 393216/390625, {{monzo| -17 21 -7 }} | ||
| | | {{mapping| 161 255 374 }} | ||
| +0.099 | | +0.099 | ||
| 0.570 | | 0.570 | ||
| Line 42: | Line 45: | ||
| 2.3.5.7 | | 2.3.5.7 | ||
| 2401/2400, 3136/3125, 177147/175000 | | 2401/2400, 3136/3125, 177147/175000 | ||
| | | {{mapping| 161 255 374 452 }} | ||
| +0.064 | | +0.064 | ||
| 0.498 | | 0.498 | ||
| Line 49: | Line 52: | ||
| 2.3.5.7.11 | | 2.3.5.7.11 | ||
| 243/242, 441/440, 3136/3125, 35937/35840 | | 243/242, 441/440, 3136/3125, 35937/35840 | ||
| | | {{mapping| 161 255 374 452 557 }} | ||
| +0.037 | | +0.037 | ||
| 0.448 | | 0.448 | ||
| Line 56: | Line 59: | ||
| 2.3.5.7.11.13 | | 2.3.5.7.11.13 | ||
| 243/242, 351/350, 441/440, 847/845, 3136/3125 | | 243/242, 351/350, 441/440, 847/845, 3136/3125 | ||
| | | {{mapping| 161 255 374 452 557 596 }} | ||
| | | −0.046 | ||
| 0.449 | | 0.449 | ||
| 6.03 | | 6.03 | ||
| Line 63: | Line 66: | ||
| 2.3.5.7.11.13.17 | | 2.3.5.7.11.13.17 | ||
| 243/242, 351/350, 441/440, 561/560, 847/845, 1089/1088 | | 243/242, 351/350, 441/440, 561/560, 847/845, 1089/1088 | ||
| | | {{mapping| 161 255 374 452 557 596 658 }} | ||
| | | −0.018 | ||
| 0.422 | | 0.422 | ||
| 5.66 | | 5.66 | ||
| Line 70: | Line 73: | ||
| 2.3.5.7.11.13.17.19 | | 2.3.5.7.11.13.17.19 | ||
| 243/242, 324/323, 351/350, 441/440, 456/455, 495/494, 513/512 | | 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 | | 0.397 | ||
| 5.32 | | 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 === | === Rank-2 temperaments === | ||
{| class="wikitable center-all left-5" | {| class="wikitable center-all left-5" | ||
|+Table of rank-2 temperaments by generator | |+ style="font-size: 105%;" | Table of rank-2 temperaments by generator | ||
! Periods<br>per | |- | ||
! Generator | ! Periods<br />per 8ve | ||
! Cents | ! Generator* | ||
! Associated<br>ratio | ! Cents* | ||
! Associated<br />ratio* | |||
! Temperaments | ! Temperaments | ||
|- | |- | ||
| Line 90: | Line 95: | ||
| 16/15 | | 16/15 | ||
| [[Vavoom]] | | [[Vavoom]] | ||
|- | |||
| 1 | |||
| 16\161 | |||
| 119.25 | |||
| 15/14 | |||
| [[Septidiasemi]] | |||
|- | |- | ||
| 1 | | 1 | ||
| Line 128: | Line 139: | ||
|- | |- | ||
| 7 | | 7 | ||
| 67\161<br>(2\161) | | 67\161<br />(2\161) | ||
| 499.38<br>(14.91) | | 499.38<br />(14.91) | ||
| 4/3<br>(81/80) | | 4/3<br />(81/80) | ||
| [[Absurdity]] | | [[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]] | [[Category:Mintone]] | ||