402edo: Difference between revisions
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{{Infobox ET}} | {{Infobox ET}} | ||
{{ | {{ED intro}} | ||
== Theory == | == Theory == | ||
402edo is only [[consistent]] to the [[5-odd-limit]]. There are three possible mappings in the 7-limit: | |||
* {{val|402 637 933 1129}} (patent val) | * {{val| 402 637 933 1129 }} ([[patent val]]) | ||
* {{val|402 637 ''' | * {{val| 402 637 933 '''1128''' }} (402d) | ||
* {{val|402 637 | * {{val| 402 637 '''934''' 1129 }} (402c) | ||
Using the patent val, it tempers out 4375/4374, 7381125/7340032 and 3200000/3176523 in the 7-limit | Using the patent val, it tempers out the [[semicomma]] in the 5-limit and [[4375/4374]], 7381125/7340032, and 3200000/3176523 in the 7-limit, [[support]]ing [[Abigail]]. | ||
Using the | Using the 402d val, it tempers out [[250047/250000]], and 1500625/1492992 and 2460375/2458624 in the 7-limit. | ||
Using the | Using the 402c val, it tempers out the [[schisma]] in the 5-limit; and [[3136/3125]], 321489/320000, and 13060694016/12867859375 in the 7-limit, supporting [[bischismic]]. | ||
=== Odd harmonics === | === Odd harmonics === | ||
Line 18: | Line 18: | ||
=== Subsets and supersets === | === Subsets and supersets === | ||
402 factors into 2 × 3 × 67, | Since 402 factors into {{nowrap|2 × 3 × 67}}, 402edo has subset edos {{EDOs| 2, 3, 6, 67, 134, and 201 }}. [[804edo]], which doubles it, gives a good correction to the harmonics 5 and 7. | ||
== Regular temperament properties == | == Regular temperament properties == | ||
{| class="wikitable center-4 center-5 center-6" | {| class="wikitable center-4 center-5 center-6" | ||
|- | |- | ||
|2.3 | ! rowspan="2" | [[Subgroup]] | ||
|{{monzo|-637 402}} | ! rowspan="2" | [[Comma list]] | ||
|{{mapping|402 637}} | ! rowspan="2" | [[Mapping]] | ||
! rowspan="2" | Optimal<br />8ve stretch (¢) | |||
! colspan="2" | Tuning error | |||
|- | |||
! [[TE error|Absolute]] (¢) | |||
! [[TE simple badness|Relative]] (%) | |||
|- | |||
| 2.3 | |||
| {{monzo| -637 402 }} | |||
| {{mapping| 402 637 }} | |||
| 0.1459 | | 0.1459 | ||
| 0.1459 | | 0.1459 | ||
| 4.89 | | 4.89 | ||
|- | |- | ||
|2.3.5 | | 2.3.5 | ||
|2109375/2097152, {{monzo|25 -48 22}} | | 2109375/2097152, {{monzo| 25 -48 22 }} | ||
|{{mapping|402 637 933}} | | {{mapping| 402 637 933 }} | ||
| 0.2752 | | 0.2752 | ||
| 0.2182 | | 0.2182 | ||
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=== 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 | |- | ||
! Generator | ! Periods<br />per 8ve | ||
! Cents | ! Generator* | ||
! Associated<br> | ! Cents* | ||
! Associated<br />ratio* | |||
! Temperaments | ! Temperaments | ||
|- | |- | ||
|1 | | 1 | ||
|91\402 | | 91\402 | ||
|271.64 | | 271.64 | ||
|75/64 | | 75/64 | ||
|[[Orson]] | | [[Orson]] (402) | ||
|- | |||
| 1 | |||
| 115\402 | |||
| 343.28 | |||
| 8000/6561 | |||
| [[Raider]] (402) | |||
|- | |- | ||
| | | 2 | ||
| | | 70\402 | ||
| | | 208.96 | ||
| | | 44/39 | ||
|[[ | | [[Abigail]] (402) | ||
| | |- | ||
| 2 | |||
| 167\402<br />(34\402) | |||
| 498.51<br />(101.49) | |||
| 4/3<br />(200/189) | |||
| [[Bischismic]] (402c, 7-limit) | |||
|} | |} | ||
<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 06:24, 21 February 2025
← 401edo | 402edo | 403edo → |
402 equal divisions of the octave (abbreviated 402edo or 402ed2), also called 402-tone equal temperament (402tet) or 402 equal temperament (402et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 402 equal parts of about 2.99 ¢ each. Each step represents a frequency ratio of 21/402, or the 402nd root of 2.
Theory
402edo is only consistent to the 5-odd-limit. There are three possible mappings in the 7-limit:
- ⟨402 637 933 1129] (patent val)
- ⟨402 637 933 1128] (402d)
- ⟨402 637 934 1129] (402c)
Using the patent val, it tempers out the semicomma in the 5-limit and 4375/4374, 7381125/7340032, and 3200000/3176523 in the 7-limit, supporting Abigail.
Using the 402d val, it tempers out 250047/250000, and 1500625/1492992 and 2460375/2458624 in the 7-limit.
Using the 402c val, it tempers out the schisma in the 5-limit; and 3136/3125, 321489/320000, and 13060694016/12867859375 in the 7-limit, supporting bischismic.
Odd harmonics
Harmonic | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 17 | 19 | 21 | 23 | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Error | Absolute (¢) | -0.46 | -1.24 | +1.32 | -0.92 | +0.92 | +1.26 | +1.28 | -0.48 | +0.99 | +0.86 | -1.41 |
Relative (%) | -15.5 | -41.5 | +44.3 | -31.0 | +30.8 | +42.3 | +43.0 | -16.0 | +33.3 | +28.8 | -47.2 | |
Steps (reduced) |
637 (235) |
933 (129) |
1129 (325) |
1274 (68) |
1391 (185) |
1488 (282) |
1571 (365) |
1643 (35) |
1708 (100) |
1766 (158) |
1818 (210) |
Subsets and supersets
Since 402 factors into 2 × 3 × 67, 402edo has subset edos 2, 3, 6, 67, 134, and 201. 804edo, which doubles it, gives a good correction to the harmonics 5 and 7.
Regular temperament properties
Subgroup | Comma list | Mapping | Optimal 8ve stretch (¢) |
Tuning error | |
---|---|---|---|---|---|
Absolute (¢) | Relative (%) | ||||
2.3 | [-637 402⟩ | [⟨402 637]] | 0.1459 | 0.1459 | 4.89 |
2.3.5 | 2109375/2097152, [25 -48 22⟩ | [⟨402 637 933]] | 0.2752 | 0.2182 | 7.31 |
Rank-2 temperaments
Periods per 8ve |
Generator* | Cents* | Associated ratio* |
Temperaments |
---|---|---|---|---|
1 | 91\402 | 271.64 | 75/64 | Orson (402) |
1 | 115\402 | 343.28 | 8000/6561 | Raider (402) |
2 | 70\402 | 208.96 | 44/39 | Abigail (402) |
2 | 167\402 (34\402) |
498.51 (101.49) |
4/3 (200/189) |
Bischismic (402c, 7-limit) |
* Octave-reduced form, reduced to the first half-octave, and minimal form in parentheses if distinct