357edo: Difference between revisions
Rework; cleanup; clarify the title row of the rank-2 temp table |
m changed EDO intro to ED intro |
||
(5 intermediate revisions by 2 users not shown) | |||
Line 1: | Line 1: | ||
{{Infobox ET}} | {{Infobox ET}} | ||
{{ | {{ED intro}} | ||
== Theory == | == Theory == | ||
While not highly accurate for its size, 357et is the point where a few important temperaments meet. | While not highly accurate for its size, 357et is the point where a few important temperaments meet. It [[tempering out|tempers out]] 1600000/1594323 ([[amity comma]]), and {{monzo| 61 4 -29 }} (squarschimidt comma) in the [[5-limit]]; 10976/10935 ([[hemimage comma]]), 235298/234375 ([[triwellisma]]), 250047/250000 ([[landscape comma]]), 2100875/2097152 ([[rainy comma]]) in the [[7-limit]]; [[3025/3024]], [[5632/5625]], [[12005/11979]] in the [[11-limit]]; [[676/675]], [[1001/1000]], [[2080/2079]], [[4096/4095]], [[4225/4224]], [[6656/6655]] and [[10648/10647]] in the [[13-limit]]. | ||
It [[support]]s 5-limit [[amity]] and 7-limit weak extensions [[calamity]] and [[chromat]]. It provides the [[optimal patent val]] for 11- and 13-limit [[hemichromat]], the 159 & 198 temperament. It also supports [[ | It [[support]]s 5-limit [[amity]] and 7-limit weak extensions [[calamity]] and [[chromat]]. It provides the [[optimal patent val]] for 11- and 13-limit [[hemichromat]], the 159 & 198 temperament. It also supports [[avicenna (temperament)|avicenna]], but [[270edo]] is better suited for this purpose. | ||
=== Prime harmonics === | === Prime harmonics === | ||
Line 11: | Line 11: | ||
=== Subsets and supersets === | === Subsets and supersets === | ||
Since 357 factors into 3 × | Since 357 factors into 3 × 7 × 17, 357edo has subset edos {{EDOs| 3, 7, 17, 21, 51, and 119 }}. | ||
== 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 | ! rowspan="2" | Optimal<br />8ve stretch (¢) | ||
! colspan="2" | Tuning | ! colspan="2" | Tuning error | ||
|- | |- | ||
! [[TE error|Absolute]] (¢) | ! [[TE error|Absolute]] (¢) | ||
Line 27: | Line 28: | ||
| {{monzo| 566 -357 }} | | {{monzo| 566 -357 }} | ||
| {{mapping| 357 566 }} | | {{mapping| 357 566 }} | ||
| | | −0.1786 | ||
| 0.1785 | | 0.1785 | ||
| 5.31 | | 5.31 | ||
Line 34: | Line 35: | ||
| 1600000/1594323, {{monzo| 61 4 -29 }} | | 1600000/1594323, {{monzo| 61 4 -29 }} | ||
| {{mapping| 357 566 829 }} | | {{mapping| 357 566 829 }} | ||
| | | −0.1536 | ||
| 0.1500 | | 0.1500 | ||
| 4.46 | | 4.46 | ||
Line 41: | Line 42: | ||
| 10976/10935, 235298/234375, 2100875/2097152 | | 10976/10935, 235298/234375, 2100875/2097152 | ||
| {{mapping| 357 566 829 1002 }} | | {{mapping| 357 566 829 1002 }} | ||
| | | −0.0477 | ||
| 0.2248 | | 0.2248 | ||
| 6.69 | | 6.69 | ||
Line 48: | Line 49: | ||
| 3025/3024, 5632/5625, 10976/10935, 102487/102400 | | 3025/3024, 5632/5625, 10976/10935, 102487/102400 | ||
| {{mapping| 357 566 829 1002 1235 }} | | {{mapping| 357 566 829 1002 1235 }} | ||
| | | −0.0348 | ||
| 0.2027 | | 0.2027 | ||
| 6.03 | | 6.03 | ||
Line 55: | Line 56: | ||
| 676/675, 1001/1000, 3025/3024, 4096/4095, 10976/10935 | | 676/675, 1001/1000, 3025/3024, 4096/4095, 10976/10935 | ||
| {{mapping| 357 566 829 1002 1235 1321 }} | | {{mapping| 357 566 829 1002 1235 1321 }} | ||
| | | −0.0204 | ||
| 0.1879 | | 0.1879 | ||
| 5.59 | | 5.59 | ||
Line 62: | Line 63: | ||
=== 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 8ve | |- | ||
! Periods<br />per 8ve | |||
! Generator* | ! Generator* | ||
! Cents* | ! Cents* | ||
! Associated<br> | ! Associated<br />ratio* | ||
! Temperaments | ! Temperaments | ||
|- | |- | ||
Line 111: | Line 113: | ||
| [[Pnict]] | | [[Pnict]] | ||
|} | |} | ||
<nowiki>* | <nowiki />* [[Normal lists|Octave-reduced form]], reduced to the first half-octave, and [[Normal lists|minimal form]] in parentheses if distinct |
Latest revision as of 06:30, 21 February 2025
← 356edo | 357edo | 358edo → |
357 equal divisions of the octave (abbreviated 357edo or 357ed2), also called 357-tone equal temperament (357tet) or 357 equal temperament (357et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 357 equal parts of about 3.36 ¢ each. Each step represents a frequency ratio of 21/357, or the 357th root of 2.
Theory
While not highly accurate for its size, 357et is the point where a few important temperaments meet. It tempers out 1600000/1594323 (amity comma), and [61 4 -29⟩ (squarschimidt comma) in the 5-limit; 10976/10935 (hemimage comma), 235298/234375 (triwellisma), 250047/250000 (landscape comma), 2100875/2097152 (rainy comma) in the 7-limit; 3025/3024, 5632/5625, 12005/11979 in the 11-limit; 676/675, 1001/1000, 2080/2079, 4096/4095, 4225/4224, 6656/6655 and 10648/10647 in the 13-limit.
It supports 5-limit amity and 7-limit weak extensions calamity and chromat. It provides the optimal patent val for 11- and 13-limit hemichromat, the 159 & 198 temperament. It also supports avicenna, but 270edo is better suited for this purpose.
Prime harmonics
Harmonic | 2 | 3 | 5 | 7 | 11 | 13 | 17 | 19 | 23 | 29 | 31 | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Error | Absolute (¢) | +0.00 | +0.57 | +0.24 | -0.76 | -0.06 | -0.19 | -0.75 | +1.65 | +0.30 | -1.01 | +1.18 |
Relative (%) | +0.0 | +16.8 | +7.2 | -22.6 | -1.7 | -5.7 | -22.4 | +49.0 | +8.8 | -29.9 | +35.2 | |
Steps (reduced) |
357 (0) |
566 (209) |
829 (115) |
1002 (288) |
1235 (164) |
1321 (250) |
1459 (31) |
1517 (89) |
1615 (187) |
1734 (306) |
1769 (341) |
Subsets and supersets
Since 357 factors into 3 × 7 × 17, 357edo has subset edos 3, 7, 17, 21, 51, and 119.
Regular temperament properties
Subgroup | Comma list | Mapping | Optimal 8ve stretch (¢) |
Tuning error | |
---|---|---|---|---|---|
Absolute (¢) | Relative (%) | ||||
2.3 | [566 -357⟩ | [⟨357 566]] | −0.1786 | 0.1785 | 5.31 |
2.3.5 | 1600000/1594323, [61 4 -29⟩ | [⟨357 566 829]] | −0.1536 | 0.1500 | 4.46 |
2.3.5.7 | 10976/10935, 235298/234375, 2100875/2097152 | [⟨357 566 829 1002]] | −0.0477 | 0.2248 | 6.69 |
2.3.5.7.11 | 3025/3024, 5632/5625, 10976/10935, 102487/102400 | [⟨357 566 829 1002 1235]] | −0.0348 | 0.2027 | 6.03 |
2.3.5.7.11.13 | 676/675, 1001/1000, 3025/3024, 4096/4095, 10976/10935 | [⟨357 566 829 1002 1235 1321]] | −0.0204 | 0.1879 | 5.59 |
Rank-2 temperaments
Periods per 8ve |
Generator* | Cents* | Associated ratio* |
Temperaments |
---|---|---|---|---|
1 | 101\357 | 339.50 | 243/200 | Amity (5-limit) |
1 | 118\357 | 396.64 | 44/35 | Squarschmidt |
1 | 163\357 | 547.90 | 48/35 | Calamity |
3 | 9\357 | 30.25 | 55/54 | Hemichromat |
3 | 18\357 | 60.50 | 28/27 | Chromat (7-limit) |
3 | 41\357 | 137.82 | 13/12 | Avicenna |
3 | 48\357 | 161.34 | 192/175 | Pnict |
* Octave-reduced form, reduced to the first half-octave, and minimal form in parentheses if distinct