398edo: Difference between revisions
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m Text replacement - "Octave-reduced form, reduced to the first half-octave, and minimal form in parentheses if distinct" to "Octave-reduced form, reduced to the first half-octave, and minimal form in parentheses if distinct" |
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{{Infobox ET}} | {{Infobox ET}} | ||
{{ | {{ED intro}} | ||
== Theory == | == Theory == | ||
| Line 9: | Line 9: | ||
=== Subsets and supersets === | === Subsets and supersets === | ||
Since 398 factors into | Since 398 factors into {{factorisation|398}}, 398edo has [[2edo]] and [[199edo]] as its subsets. | ||
== Regular temperament properties == | == 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 | | 2.3 | ||
| {{monzo| 631 -398 }} | | {{monzo| 631 -398 }} | ||
| {{mapping| 398 631 }} | | {{mapping| 398 631 }} | ||
| | | −0.1759 | ||
| 0.1759 | | 0.1759 | ||
| 5.83 | | 5.83 | ||
| Line 24: | Line 33: | ||
| 390625000/387420489, {{monzo| -53 10 16 }} | | 390625000/387420489, {{monzo| -53 10 16 }} | ||
| {{mapping| 398 631 924 }} | | {{mapping| 398 631 924 }} | ||
| | | −0.0622 | ||
| 0.2157 | | 0.2157 | ||
| 7.15 | | 7.15 | ||
| Line 45: | Line 54: | ||
| 625/624, 1575/1573, 2080/2079, 2200/2197, 10976/10935 | | 625/624, 1575/1573, 2080/2079, 2200/2197, 10976/10935 | ||
| {{mapping| 398 631 924 1117 1377 1473 }} | | {{mapping| 398 631 924 1117 1377 1473 }} | ||
| | | −0.0243 | ||
| 0.2313 | | 0.2313 | ||
| 7.67 | | 7.67 | ||
|} | |||
=== Rank-2 temperaments === | === 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 | | 1 | ||
| Line 70: | Line 86: | ||
| 11/10 | | 11/10 | ||
| [[Bisupermajor]] | | [[Bisupermajor]] | ||
|} | |||
<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 | |||
Latest revision as of 13:31, 13 March 2026
| ← 397edo | 398edo | 399edo → |
398 equal divisions of the octave (abbreviated 398edo or 398ed2), also called 398-tone equal temperament (398tet) or 398 equal temperament (398et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 398 equal parts of about 3.02 ¢ each. Each step represents a frequency ratio of 21/398, or the 398th root of 2.
Theory
398edo is only consistent to the 5-odd-limit, though it has a reasonable approximation to the full 13-limit using the patent val, which tempers out 10976/10935, 65625/65536, 1500625/1492992, 102760448/102515625, 102942875/102036672, and 200120949/200000000 in the 7-limit; 3025/3024, 4000/3993, 6250/6237, 59290/59049, 117649/117128, and 131072/130977 in the 11-limit; and 625/624, 1575/1573, 2080/2079, 2200/2197, 4096/4095, and 4225/4224 in the 13-limit. It supports yarman I, bisupermajor and semiquindromeda.
Prime harmonics
| Harmonic | 2 | 3 | 5 | 7 | 11 | 13 | 17 | 19 | 23 | 29 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | +0.00 | +0.56 | -0.38 | -0.99 | +0.44 | +0.68 | +0.57 | +0.98 | -1.14 | -1.44 | +0.69 |
| Relative (%) | +0.0 | +18.5 | -12.7 | -32.7 | +14.6 | +22.5 | +19.0 | +32.5 | -37.8 | -47.6 | +23.0 | |
| Steps (reduced) |
398 (0) |
631 (233) |
924 (128) |
1117 (321) |
1377 (183) |
1473 (279) |
1627 (35) |
1691 (99) |
1800 (208) |
1933 (341) |
1972 (380) | |
Subsets and supersets
Since 398 factors into 2 × 199, 398edo has 2edo and 199edo as its subsets.
Regular temperament properties
| Subgroup | Comma list | Mapping | Optimal 8ve stretch (¢) |
Tuning error | |
|---|---|---|---|---|---|
| Absolute (¢) | Relative (%) | ||||
| 2.3 | [631 -398⟩ | [⟨398 631]] | −0.1759 | 0.1759 | 5.83 |
| 2.3.5 | 390625000/387420489, [-53 10 16⟩ | [⟨398 631 924]] | −0.0622 | 0.2157 | 7.15 |
| 2.3.5.7 | 10976/10935, 65625/65536, 200120949/200000000 | [⟨398 631 924 1117]] | +0.0412 | 0.2588 | 8.58 |
| 2.3.5.7.11 | 3025/3024, 4000/3993, 10976/10935, 65625/65536 | [⟨398 631 924 1117 1377]] | +0.0075 | 0.2411 | 8.00 |
| 2.3.5.7.11.13 | 625/624, 1575/1573, 2080/2079, 2200/2197, 10976/10935 | [⟨398 631 924 1117 1377 1473]] | −0.0243 | 0.2313 | 7.67 |
Rank-2 temperaments
| Periods per 8ve |
Generator* | Cents* | Associated ratio* |
Temperaments |
|---|---|---|---|---|
| 1 | 5\398 | 15.08 | 126/125 | Yarman I |
| 1 | 183\398 | 551.76 | 11/8 | Emkay |
| 2 | 54\398 | 162.81 | 11/10 | Bisupermajor |
* Octave-reduced form, reduced to the first half-octave, and minimal form in parentheses if distinct