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{{Infobox ET}} | |||
[[Category: | {{ED intro}} | ||
[[Category: | |||
[[Category: | == Theory == | ||
665edo is best known for its unfathomably accurate [[3/2|fifth]], only 0.00011 cents compressed. 665edo is the denominator of a convergent to log<sub>2</sub>3, after [[41edo]], [[53edo]], and [[306edo]], and before [[15601edo]], and is the member of this series with the highest 3-2 [[Telicity #k-Strong Telicity|telicity ''k''-strength]] before being finally surpassed in this regard by [[190537edo]]. | |||
However, it also provides the [[optimal patent val]] for the rank-4 temperament tempering out [[4000/3993]]. It [[tempering out|tempers out]] the [[satanic comma]], {{monzo| -1054 665 }} in the 3-limit; the [[enneadeca]], {{monzo| -14 -19 19 }}, and the [[monzisma]], {{monzo| 54 -37 2 }} in the 5-limit; the [[ragisma]], 4375/4374, the [[meter]], 703125/702464, and {{monzo| 36 -5 0 -10 }} in the 7-limit; [[4000/3993]], 46656/46585, [[131072/130977]] and 151263/151250 in the 11-limit, providing the optimal patent val for the 11-limit [[brahmagupta]] temperament. In the 13-limit, it tempers out [[1575/1573]], [[2080/2079]], [[4096/4095]], and [[4225/4224]]; since it tempers out 1575/1573, the nicola, it [[support]]s nicolic tempering and hence the [[nicolic chords]], for which it provides an excellent tuning. In the 17-limit it tempers out [[1156/1155]], [[1275/1274]], [[2058/2057]], [[2500/2499]] and [[5832/5831]]; in the 19-limit it tempers out 969/968, [[1445/1444]], 2432/2431, 3136/3135, 3250/3249, and 4200/4199; in the 23-limit it tempers out 1288/1287, 1863/1862, 2025/2024, 2185/2184, and 2737/2736. | |||
665edo provides relatively great approximations for the 7-limit intervals and harmonics 13, 17, 19, and 23, with minuscule absolute error. It is considered as an excellent 2.3.5.7.13.17.19.23 subgroup temperament, on which it is consistent in the [[27-odd-limit]], and in the full 27-odd-limit, the only inconsistencies are [[11/10]], [[25/22]], [[15/11]], [[17/11]], [[23/22]], and their [[octave complement]]s. 665edo provides relatively poor approximations for intervals of 11, with two mappings possible for the [[11/8]] fourth: a sharp one from the [[patent val]], and a flat one from the 665e val. Using the 665e val, [[41503/41472]], 42592/42525, 160083/160000, and 539055/537824 are tempered out in the 11-limit. | |||
=== Prime harmonics === | |||
{{Harmonics in equal|665}} | |||
=== Subsets and supersets === | |||
Since 665 factors into {{factorisation|665}}, 665edo has subset edos {{EDOs| 5, 7, 19, 35, 95, and 133 }}. One step of 665edo has been proposed as an [[interval size measure]], called a '''Delfi unit'''. A Delfi unit is exactly 48 imps ([[31920edo|48\31920]]). | |||
[[1330edo]], which doubles 665edo, provides a good correction of the harmonic 11. | |||
[[7315edo]], which undecuples 665edo, is the last 3-2 telic multiple, and fully consistent to the [[27-odd-limit]] and almost the [[31-odd-limit]]. | |||
=== Miscellany === | |||
A [[maximal evenness]] scale deriving from the {{nowrap|118 & 665}} temperament, known as [[vavoom]], can also theoretically serve as a calendar leap week cycle corresponding to a year length of {{nowrap| 365d 5h 48m 37{{frac|17|19}}s}}, about 7 seconds shorter than the average length of the tropical year today. Given the excellence of both 118 and 665 in 5-limit, this is a great point of intersection of solar calendar leap rules and just intonation-based temperaments. | |||
== Intervals == | |||
See [[Table of 665edo intervals]]. | |||
== 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| -1054 665 }} | |||
| {{Mapping| 665 1054 }} | |||
| +0.0000 | |||
| 0.0000 | |||
| 0.00 | |||
|- | |||
| 2.3.5 | |||
| {{Monzo| -14 -19 19 }}, {{monzo| 54 -37 2 }} | |||
| {{Mapping| 665 1054 1544 }} | |||
| +0.0213 | |||
| 0.0301 | |||
| 1.67 | |||
|- | |||
| 2.3.5.7 | |||
| 4375/4374, 703125/702464, {{monzo| 36 -5 0 -10 }} | |||
| {{Mapping| 665 1054 1544 1867 }} | |||
| −0.0015 | |||
| 0.0474 | |||
| 2.63 | |||
|- | |||
| 2.3.5.7.11 | |||
| 4000/3993, 4375/4374, 117649/117612, 131072/130977 | |||
| {{Mapping| 665 1054 1544 1867 2301 }} | |||
| −0.0511 | |||
| 0.1078 | |||
| 5.97 | |||
|- | |||
| 2.3.5.7.11.13 | |||
| 1575/1573, 2080/2079, 4096/4095, 4375/4374, 31250/31213 | |||
| {{Mapping| 665 1054 1544 1867 2301 2461 }} | |||
| −0.0594 | |||
| 0.1002 | |||
| 5.55 | |||
|} | |||
=== 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 | |||
| 62\665 | |||
| 111.88 | |||
| 16/15 | |||
| [[Vavoom]] | |||
|- | |||
| 1 | |||
| 138\665 | |||
| 249.02 | |||
| {{Monzo| -26 18 -1 }} | |||
| [[Monzismic]] | |||
|- | |||
| 7 | |||
| 288\665<br>(3\665) | |||
| 519.70<br>(5.41) | |||
| 27/20<br>(325/324) | |||
| [[Brahmagupta]] | |||
|- | |||
| 19 | |||
| 276\665<br>(4\665) | |||
| 498.05<br>(7.21) | |||
| 4/3<br>(225//224) | |||
| [[Enneadecal]] | |||
|} | |||
<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:3-limit record edos|###]] <!-- 3-digit number --> | |||
[[Category:Satanic]] | |||
[[Category:Wizardharry]] | |||
[[Category:Monzismic]] | |||