494edo: Difference between revisions
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{{Infobox ET}} | {{Infobox ET}} | ||
{{ | {{ED intro}} | ||
== Theory == | == Theory == | ||
494 is a very strong [[13-limit|13]]- and [[17-limit]] equal temperament. 494edo is a [[zeta edo|zeta peak and zeta peak integer edo]] and [[consistency|distinctly consistent]] through the [[17-odd-limit]]. It [[tempering out|tempers out]] the [[enneadeca]], {{monzo| -14 -19 19 }}, the [[ | 494 is a very strong [[13-limit|13]]- and [[17-limit]] equal temperament. 494edo is a [[zeta edo|zeta peak and zeta peak integer edo]] and [[consistency|distinctly consistent]] through the [[17-odd-limit]]. It [[tempering out|tempers out]] the [[enneadeca]], {{monzo| -14 -19 19 }}, the [[alphatricot comma]], {{monzo| 39 -29 3 }}, and the [[kwazy comma]], {{monzo| -53 10 16 }} in the [[5-limit]]. In the [[7-limit]], it tempers out [[4375/4374]] and [[703125/702464]]; in the [[11-limit]] [[3025/3024]] and [[9801/9800]]; in the [[13-limit]] [[1716/1715]], [[2080/2079]], [[4096/4095]], [[4225/4224]] and [[6656/6655]]; and in the 17-limit, [[1156/1155]], 1275/1274, 2431/2430, and 2500/2499. | ||
Since the step size is close to [[729/728]], the squbema, the accepted name for 494edo's step is ''squb''. | Since the step size is close to [[729/728]], the squbema, the accepted name for 494edo's step is ''squb''. | ||
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! rowspan="2" | [[Comma list]] | ! rowspan="2" | [[Comma list]] | ||
! rowspan="2" | [[Mapping]] | ! rowspan="2" | [[Mapping]] | ||
! rowspan="2" | Optimal<br | ! rowspan="2" | Optimal<br>8ve stretch (¢) | ||
! colspan="2" | Tuning error | ! colspan="2" | Tuning error | ||
|- | |- | ||
| Line 32: | Line 32: | ||
|- | |- | ||
| 2.3 | | 2.3 | ||
| {{ | | {{Monzo| 783 -494 }} | ||
| {{ | | {{Mapping| 494 783 }} | ||
| −0.0219 | | −0.0219 | ||
| 0.0219 | | 0.0219 | ||
| Line 39: | Line 39: | ||
|- | |- | ||
| 2.3.5 | | 2.3.5 | ||
| {{ | | {{Monzo| -14 -19 19 }}, {{monzo| 39 -23 3 }} | ||
| {{ | | {{Mapping| 494 783 1147 }} | ||
| −0.0032 | | −0.0032 | ||
| 0.0318 | | 0.0318 | ||
| Line 47: | Line 47: | ||
| 2.3.5.7 | | 2.3.5.7 | ||
| 4375/4374, 703125/702464, {{monzo| 21 3 1 -10 }} | | 4375/4374, 703125/702464, {{monzo| 21 3 1 -10 }} | ||
| {{ | | {{Mapping| 494 783 1147 1387 }} | ||
| −0.0385 | | −0.0385 | ||
| 0.0670 | | 0.0670 | ||
| Line 54: | Line 54: | ||
| 2.3.5.7.11 | | 2.3.5.7.11 | ||
| 3025/3024, 4375/4374, 131072/130977, 234375/234256 | | 3025/3024, 4375/4374, 131072/130977, 234375/234256 | ||
| {{ | | {{Mapping| 494 783 1147 1387 1709 }} | ||
| −0.0365 | | −0.0365 | ||
| 0.0600 | | 0.0600 | ||
| Line 61: | Line 61: | ||
| 2.3.5.7.11.13 | | 2.3.5.7.11.13 | ||
| 1716/1715, 2080/2079, 3025/3024, 4096/4095, 31250/31213 | | 1716/1715, 2080/2079, 3025/3024, 4096/4095, 31250/31213 | ||
| {{ | | {{Mapping| 494 783 1147 1387 1709 1828 }} | ||
| −0.0286 | | −0.0286 | ||
| 0.0576 | | 0.0576 | ||
| Line 68: | Line 68: | ||
| 2.3.5.7.11.13.17 | | 2.3.5.7.11.13.17 | ||
| 1156/1155, 1275/1274, 1716/1715, 2080/2079, 2431/2430, 4096/4095 | | 1156/1155, 1275/1274, 1716/1715, 2080/2079, 2431/2430, 4096/4095 | ||
| {{ | | {{Mapping| 494 783 1147 1387 1709 1828 2019 }} | ||
| −0.0069 | | −0.0069 | ||
| 0.0752 | | 0.0752 | ||
| Line 79: | Line 79: | ||
|+ style="font-size: 105%;" | Table of rank-2 temperaments by generator | |+ style="font-size: 105%;" | Table of rank-2 temperaments by generator | ||
|- | |- | ||
! Periods<br | ! Periods<br>per 8ve | ||
! Generator* | ! Generator* | ||
! Cents* | ! Cents* | ||
! Associated<br | ! Associated<br>ratio* | ||
! Temperaments | ! Temperaments | ||
|- | |- | ||
| Line 101: | Line 101: | ||
| 565.99 | | 565.99 | ||
| 104/75 | | 104/75 | ||
| [[ | | [[Alphatrillium]] | ||
|- | |- | ||
| 2 | | 2 | ||
| Line 107: | Line 107: | ||
| 162.75 | | 162.75 | ||
| 1125/1024 | | 1125/1024 | ||
| [[ | | [[Crazy]] | ||
|- | |- | ||
| 2 | | 2 | ||
| Line 116: | Line 116: | ||
|- | |- | ||
| 13 | | 13 | ||
| 205\494<br | | 205\494<br>(15\494) | ||
| 497.98<br />(36.43) | | 497.98<br/>(36.43) | ||
| 4/3<br | | 4/3<br>(?) | ||
| [[Aluminium]] | | [[Aluminium]] | ||
|- | |- | ||
| 19 | | 19 | ||
| 205\494<br | | 205\494<br>(3\494) | ||
| 497.98<br | | 497.98<br>(7.29) | ||
| 4/3<br | | 4/3<br>(225/224) | ||
| [[Enneadecal]] | | [[Enneadecal]] | ||
|- | |- | ||
| 38 | | 38 | ||
| 205\494<br | | 205\494<br>(3\494) | ||
| 497.98<br | | 497.98<br>(7.29) | ||
| 4/3<br | | 4/3<br>(225/224) | ||
| [[Hemienneadecal]] | | [[Hemienneadecal]] | ||
|- | |- | ||
| 38 | | 38 | ||
| 109\494<br | | 109\494<br>(5\494) | ||
| 264.78<br | | 264.78<br>(12.15) | ||
| 500/429<br | | 500/429<br>(144/143) | ||
| [[Semihemienneadecal]] | | [[Semihemienneadecal]] | ||
|} | |} | ||
<nowiki />* [[Normal | <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 | ||
== Music == | == Music == | ||
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[[Category:Kwazy]] | [[Category:Kwazy]] | ||
[[Category:Listen]] | [[Category:Listen]] | ||
[[Category: | [[Category:Alphatricot]] | ||
Latest revision as of 13:38, 13 March 2026
| ← 493edo | 494edo | 495edo → |
494 equal divisions of the octave (abbreviated 494edo or 494ed2), also called 494-tone equal temperament (494tet) or 494 equal temperament (494et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 494 equal parts of about 2.43 ¢ each. Each step represents a frequency ratio of 21/494, or the 494th root of 2.
Theory
494 is a very strong 13- and 17-limit equal temperament. 494edo is a zeta peak and zeta peak integer edo and distinctly consistent through the 17-odd-limit. It tempers out the enneadeca, [-14 -19 19⟩, the alphatricot comma, [39 -29 3⟩, and the kwazy comma, [-53 10 16⟩ in the 5-limit. In the 7-limit, it tempers out 4375/4374 and 703125/702464; in the 11-limit 3025/3024 and 9801/9800; in the 13-limit 1716/1715, 2080/2079, 4096/4095, 4225/4224 and 6656/6655; and in the 17-limit, 1156/1155, 1275/1274, 2431/2430, and 2500/2499.
Since the step size is close to 729/728, the squbema, the accepted name for 494edo's step is squb.
Prime harmonics
| Harmonic | 2 | 3 | 5 | 7 | 11 | 13 | 17 | 19 | 23 | 29 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | +0.000 | +0.069 | -0.079 | +0.405 | +0.099 | -0.042 | -0.502 | -1.157 | +0.875 | +0.382 | -0.906 |
| Relative (%) | +0.0 | +2.9 | -3.2 | +16.7 | +4.1 | -1.7 | -20.7 | -47.6 | +36.0 | +15.7 | -37.3 | |
| Steps (reduced) |
494 (0) |
783 (289) |
1147 (159) |
1387 (399) |
1709 (227) |
1828 (346) |
2019 (43) |
2098 (122) |
2235 (259) |
2400 (424) |
2447 (471) | |
Subsets and supersets
Since 494 factors into 2 × 13 × 19, 494edo has subset edos 2, 13, 19, 26, 38, and 247.
988edo, which slices the edostep in two, provides a good correction of the 19th harmonic. 2964edo, which slices the edostep in six, provides an extremely precise correction of the 7th harmonic.
Intervals
The following table shows how 15-odd-limit intervals are represented in 494edo. Prime harmonics are in bold.
As 494edo is consistent in the 15-odd-limit, the mappings by direct approximation and through the patent val are identical.
| Interval and complement | Error (abs, ¢) | Error (rel, %) |
|---|---|---|
| 1/1, 2/1 | 0.000 | 0.0 |
| 15/8, 16/15 | 0.010 | 0.4 |
| 11/6, 12/11 | 0.030 | 1.2 |
| 15/13, 26/15 | 0.032 | 1.3 |
| 13/10, 20/13 | 0.037 | 1.5 |
| 11/9, 18/11 | 0.040 | 1.6 |
| 13/8, 16/13 | 0.042 | 1.7 |
| 3/2, 4/3 | 0.069 | 2.9 |
| 5/4, 8/5 | 0.079 | 3.2 |
| 11/8, 16/11 | 0.099 | 4.1 |
| 15/11, 22/15 | 0.109 | 4.5 |
| 13/12, 24/13 | 0.111 | 4.6 |
| 9/8, 16/9 | 0.139 | 5.7 |
| 13/11, 22/13 | 0.141 | 5.8 |
| 5/3, 6/5 | 0.148 | 6.1 |
| 11/10, 20/11 | 0.178 | 7.3 |
| 13/9, 18/13 | 0.180 | 7.4 |
| 9/5, 10/9 | 0.217 | 9.0 |
| 9/7, 14/9 | 0.266 | 11.0 |
| 11/7, 14/11 | 0.306 | 12.6 |
| 7/6, 12/7 | 0.336 | 13.8 |
| 7/4, 8/7 | 0.405 | 16.7 |
| 15/14, 28/15 | 0.414 | 17.1 |
| 13/7, 14/13 | 0.447 | 18.4 |
| 7/5, 10/7 | 0.484 | 19.9 |
Regular temperament properties
| Subgroup | Comma list | Mapping | Optimal 8ve stretch (¢) |
Tuning error | |
|---|---|---|---|---|---|
| Absolute (¢) | Relative (%) | ||||
| 2.3 | [783 -494⟩ | [⟨494 783]] | −0.0219 | 0.0219 | 0.90 |
| 2.3.5 | [-14 -19 19⟩, [39 -23 3⟩ | [⟨494 783 1147]] | −0.0032 | 0.0318 | 1.31 |
| 2.3.5.7 | 4375/4374, 703125/702464, [21 3 1 -10⟩ | [⟨494 783 1147 1387]] | −0.0385 | 0.0670 | 2.76 |
| 2.3.5.7.11 | 3025/3024, 4375/4374, 131072/130977, 234375/234256 | [⟨494 783 1147 1387 1709]] | −0.0365 | 0.0600 | 2.47 |
| 2.3.5.7.11.13 | 1716/1715, 2080/2079, 3025/3024, 4096/4095, 31250/31213 | [⟨494 783 1147 1387 1709 1828]] | −0.0286 | 0.0576 | 2.37 |
| 2.3.5.7.11.13.17 | 1156/1155, 1275/1274, 1716/1715, 2080/2079, 2431/2430, 4096/4095 | [⟨494 783 1147 1387 1709 1828 2019]] | −0.0069 | 0.0752 | 3.09 |
- 494et has lower relative errors than any previous equal temperaments in the 13- and 17-limit. It is the first past 270 with a lower 13-limit relative error, and the first past 72 with a lower 17-limit relative error. It is narrowly beaten by 684 in terms of 13-limit absolute error and by 581 in terms of 17-limit absolute error. Not until 1506 do we reach an equal temperament with a lower relative error in either subgroup.
Rank-2 temperaments
| Periods per 8ve |
Generator* | Cents* | Associated ratio* |
Temperaments |
|---|---|---|---|---|
| 1 | 27\494 | 65.59 | 27/26 | Luminal |
| 1 | 119\494 | 289.07 | 13/11 | Moulin |
| 1 | 233\494 | 565.99 | 104/75 | Alphatrillium |
| 2 | 67\494 | 162.75 | 1125/1024 | Crazy |
| 2 | 86\494 | 208.91 | 44/39 | Abigail |
| 13 | 205\494 (15\494) |
497.98 (36.43) |
4/3 (?) |
Aluminium |
| 19 | 205\494 (3\494) |
497.98 (7.29) |
4/3 (225/224) |
Enneadecal |
| 38 | 205\494 (3\494) |
497.98 (7.29) |
4/3 (225/224) |
Hemienneadecal |
| 38 | 109\494 (5\494) |
264.78 (12.15) |
500/429 (144/143) |
Semihemienneadecal |
* Octave-reduced form, reduced to the first half-octave, and minimal form in parentheses if distinct
Music
- Unknown piece in Abigail (2023)