981edo: Difference between revisions
mNo edit summary |
ArrowHead294 (talk | contribs) mNo edit summary |
||
(9 intermediate revisions by 3 users not shown) | |||
Line 1: | Line 1: | ||
{{Infobox ET}} | |||
{{ | {{ED intro}} | ||
== Theory == | == Theory == | ||
981edo is a good 13- and 17-limit system. | 981edo is a good 13- and 17-limit system, [[consistent]] to the [[17-odd-limit]]. As an equal temperament, it [[tempering out|tempers out]] [[2080/2079]], [[2401/2400]], [[2431/2430]], [[4096/4095]], [[4225/4224]], [[4375/4374]], 4459/4455 and [[4914/4913]] in the 17-limit. It provides the [[optimal patent val]] for 13-limit [[ennealimmic]], the rank-3 temperament tempering out 2080/2079, 2401/2400, and 4375/4374, and for 13-limit [[ennealimmia]], which also tempers out 4096/4095. | ||
=== Prime harmonics === | === Prime harmonics === | ||
{{Harmonics in equal|981 | {{Harmonics in equal|981}} | ||
=== | === Subsets and supersets === | ||
Since 981 | Since 981 factors into primes as 3<sup>2</sup> × 109, 981edo has subset edos 3, 9, 109, and 327. | ||
== 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 24: | Line 25: | ||
| 2.3 | | 2.3 | ||
| {{monzo| 1555 -981 }} | | {{monzo| 1555 -981 }} | ||
| | | {{mapping| 981 1555 }} | ||
| | | −0.0586 | ||
| 0.0586 | | 0.0586 | ||
| 4.79 | | 4.79 | ||
Line 31: | Line 32: | ||
| 2.3.5 | | 2.3.5 | ||
| {{monzo| 1 -27 18 }}, {{monzo| 85 -17 -25 }} | | {{monzo| 1 -27 18 }}, {{monzo| 85 -17 -25 }} | ||
| | | {{mapping| 981 1555 2278 }} | ||
| | | −0.0722 | ||
| 0.0515 | | 0.0515 | ||
| 4.21 | | 4.21 | ||
Line 38: | Line 39: | ||
| 2.3.5.7 | | 2.3.5.7 | ||
| 2401/2400, 4375/4374, {{monzo| 79 -25 -23 5 }} | | 2401/2400, 4375/4374, {{monzo| 79 -25 -23 5 }} | ||
| | | {{mapping| 981 1555 2278 2754 }} | ||
| | | −0.0385 | ||
| 0.0562 | | 0.0562 | ||
| 4.59 | | 4.59 | ||
Line 45: | Line 46: | ||
| 2.3.5.7.11 | | 2.3.5.7.11 | ||
| 2401/2400, 4375/4374, 131072/130977, 1771561/1771470 | | 2401/2400, 4375/4374, 131072/130977, 1771561/1771470 | ||
| | | {{mapping| 981 1555 2278 2754 3394 }} | ||
| | | −0.0630 | ||
| 0.0545 | | 0.0545 | ||
| 4.46 | | 4.46 | ||
Line 52: | Line 53: | ||
| 2.3.5.7.11.13 | | 2.3.5.7.11.13 | ||
| 2080/2079, 2401/2400, 4096/4095, 4375/4374, 1771561/1771470 | | 2080/2079, 2401/2400, 4096/4095, 4375/4374, 1771561/1771470 | ||
| | | {{mapping| 981 1555 2278 2754 3394 3630 }} | ||
| | | −0.0453 | ||
| 0.0636 | | 0.0636 | ||
| 5.20 | | 5.20 | ||
Line 59: | Line 60: | ||
| 2.3.5.7.11.13.17 | | 2.3.5.7.11.13.17 | ||
| 2080/2079, 2401/2400, 2431/2430, 4096/4095, 4375/4374, 4914/4913 | | 2080/2079, 2401/2400, 2431/2430, 4096/4095, 4375/4374, 4914/4913 | ||
| | | {{mapping| 981 1555 2278 2754 3394 3630 4010 }} | ||
| | | −0.0473 | ||
| 0.0591 | | 0.0591 | ||
| 4.83 | | 4.83 | ||
Line 67: | Line 68: | ||
=== Rank-2 temperaments === | === Rank-2 temperaments === | ||
{| class="wikitable center-all left-5" | {| class="wikitable center-all left-5" | ||
! Periods<br>per 8ve | |+ style="font-size: 105%;" | Table of rank-2 temperaments by generator | ||
! Generator | |- | ||
! Cents | ! Periods<br />per 8ve | ||
! Associated<br> | ! Generator* | ||
! Cents* | |||
! Associated<br />ratio* | |||
! Temperaments | ! Temperaments | ||
|- | |- | ||
Line 77: | Line 80: | ||
| 500.306 | | 500.306 | ||
| 8192/6137 | | 8192/6137 | ||
| [[ | | [[Protolangwidge]] | ||
|- | |- | ||
| 9 | | 9 | ||
| 258\981<br>(40\981) | | 258\981<br />(40\981) | ||
| 315.60<br>(48.93) | | 315.60<br />(48.93) | ||
| 6/5<br>(36/35) | | 6/5<br />(36/35) | ||
| [[Ennealimmal]] / ennealimmia | | [[Ennealimmal]] / ennealimmia | ||
|} | |} | ||
<nowiki />* [[Normal lists|Octave-reduced form]], reduced to the first half-octave, and [[Normal lists|minimal form]] in parentheses if distinct | |||
[[Category:Ennealimmic]] | [[Category:Ennealimmic]] | ||
[[Category:Ennealimmia]] | [[Category:Ennealimmia]] |
Latest revision as of 23:09, 20 February 2025
← 980edo | 981edo | 982edo → |
981 equal divisions of the octave (abbreviated 981edo or 981ed2), also called 981-tone equal temperament (981tet) or 981 equal temperament (981et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 981 equal parts of about 1.22 ¢ each. Each step represents a frequency ratio of 21/981, or the 981st root of 2.
Theory
981edo is a good 13- and 17-limit system, consistent to the 17-odd-limit. As an equal temperament, it tempers out 2080/2079, 2401/2400, 2431/2430, 4096/4095, 4225/4224, 4375/4374, 4459/4455 and 4914/4913 in the 17-limit. It provides the optimal patent val for 13-limit ennealimmic, the rank-3 temperament tempering out 2080/2079, 2401/2400, and 4375/4374, and for 13-limit ennealimmia, which also tempers out 4096/4095.
Prime harmonics
Harmonic | 2 | 3 | 5 | 7 | 11 | 13 | 17 | 19 | 23 | 29 | 31 | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Error | Absolute (¢) | +0.000 | +0.186 | +0.231 | -0.019 | +0.364 | -0.161 | +0.243 | -0.265 | +0.472 | +0.392 | -0.081 |
Relative (%) | +0.0 | +15.2 | +18.9 | -1.5 | +29.8 | -13.1 | +19.9 | -21.7 | +38.6 | +32.1 | -6.7 | |
Steps (reduced) |
981 (0) |
1555 (574) |
2278 (316) |
2754 (792) |
3394 (451) |
3630 (687) |
4010 (86) |
4167 (243) |
4438 (514) |
4766 (842) |
4860 (936) |
Subsets and supersets
Since 981 factors into primes as 32 × 109, 981edo has subset edos 3, 9, 109, and 327.
Regular temperament properties
Subgroup | Comma list | Mapping | Optimal 8ve stretch (¢) |
Tuning error | |
---|---|---|---|---|---|
Absolute (¢) | Relative (%) | ||||
2.3 | [1555 -981⟩ | [⟨981 1555]] | −0.0586 | 0.0586 | 4.79 |
2.3.5 | [1 -27 18⟩, [85 -17 -25⟩ | [⟨981 1555 2278]] | −0.0722 | 0.0515 | 4.21 |
2.3.5.7 | 2401/2400, 4375/4374, [79 -25 -23 5⟩ | [⟨981 1555 2278 2754]] | −0.0385 | 0.0562 | 4.59 |
2.3.5.7.11 | 2401/2400, 4375/4374, 131072/130977, 1771561/1771470 | [⟨981 1555 2278 2754 3394]] | −0.0630 | 0.0545 | 4.46 |
2.3.5.7.11.13 | 2080/2079, 2401/2400, 4096/4095, 4375/4374, 1771561/1771470 | [⟨981 1555 2278 2754 3394 3630]] | −0.0453 | 0.0636 | 5.20 |
2.3.5.7.11.13.17 | 2080/2079, 2401/2400, 2431/2430, 4096/4095, 4375/4374, 4914/4913 | [⟨981 1555 2278 2754 3394 3630 4010]] | −0.0473 | 0.0591 | 4.83 |
Rank-2 temperaments
Periods per 8ve |
Generator* | Cents* | Associated ratio* |
Temperaments |
---|---|---|---|---|
1 | 409\981 | 500.306 | 8192/6137 | Protolangwidge |
9 | 258\981 (40\981) |
315.60 (48.93) |
6/5 (36/35) |
Ennealimmal / ennealimmia |
* Octave-reduced form, reduced to the first half-octave, and minimal form in parentheses if distinct