13edt: Difference between revisions
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{{Infobox ET}} | {{Infobox ET}} | ||
[[File:13edt.png|thumb|alt=13edt.png|A plot of the [[ | [[File:13edt.png|thumb|alt=13edt.png|A plot of the [[the Riemann zeta function and tuning#Removing primes|no-twos Z-function]], in terms of which 13edt is the fourth no-twos zeta peak [[EDT]].]] | ||
'''13 equal divisions of the tritave''' ('''13edt''') is the [[nonoctave]] [[tuning system]] derived by dividing the [[tritave]] (3/1) into 13 equal steps of 146.3 [[cent]]s each, or the thirteenth root of 3. It is best known as the equal-tempered version of the [[ | '''13 equal divisions of the tritave''' ('''13edt''') is the [[nonoctave]] [[tuning system]] derived by dividing the [[tritave]] (3/1) into 13 equal steps of 146.3 [[cent]]s each, or the thirteenth root of 3. It is best known as the equal-tempered version of the [[Bohlen–Pierce]] scale, and therefore has received by far the most attention among equal divisions of the tritave. | ||
It provides an excellent approximation to the [[3.5.7 subgroup]], especially for its size, being comparable to [[34edo]]'s accuracy in the 5-limit. In this subgroup, it tempers out [[245/243]] and [[3125/3087]], the same commas as [[Sensamagic_clan#Bohpier|bohpier temperament]]. It is less impressive in higher prime limits, but makes for excellent no-twos 7-limit harmony. For higher limits, the multiples of 13 ([[26edt]], [[39edt]], and [[52edt]]) come to the fore. | |||
13edt can be described as approximately 8.202[[edo]]. This implies that each step of 13edt can be approximated by 5 steps of [[41edo]]. | 13edt can be described as approximately 8.202[[edo]]. This implies that each step of 13edt can be approximated by 5 steps of [[41edo]]. | ||
In the | In the [[no-2]] [[3/1]]-[[equave]]-[[7-limit]], [[13edt]] maintains the smallest relative error of any EDT until [[258edt]] and [[271edt]], and the smallest absolute error until [[56edt]]. | ||
== Theory == | == Theory == | ||
{ | {{Harmonics in equal|13|3|1|prec=2|intervals=odd}} | ||
{{Harmonics in equal|13|3|1|prec=2|intervals=odd|start=12}} | |||
| | |||
| | |||
| 13 | |||
| | |||
| | |||
| | |||
|} | |||
* [[Relationship between Bohlen-Pierce and octave-ful temperaments]] | * [[Relationship between Bohlen-Pierce and octave-ful temperaments]] | ||
| Line 68: | Line 19: | ||
{{Main|Intervals of BP}} | {{Main|Intervals of BP}} | ||
{| class="wikitable center- | {| class="wikitable center-all right-2 right-3" | ||
|- | |- | ||
! Steps | ! Steps | ||
! [[Cent]]s | ! [[Cent]]s | ||
! [[Hekt]]s | ! [[Hekt]]s | ||
! | ! [[4L 5s (3/1-equivalent)|Enneatonic]]<br />degree | ||
! Corresponding | ! Corresponding<br />3.5.7 subgroup<br />intervals | ||
! [[Lambda ups and downs notation|Lambda]]<br />(sLsLsLsLs, {{nowrap|E {{=}} 1/1}}) | |||
|- | |||
! [[ | | 0 | ||
| 0 | |||
| 0 | |||
| P1 | |||
| 1/1 | |||
| E | |||
|- | |- | ||
| 1 | | 1 | ||
| Line 83: | Line 39: | ||
| 100 | | 100 | ||
| A1/m2 | | A1/m2 | ||
| 27/25 | | [[49/45]] (−1.1{{c}}); [[27/25]] (+13.1{{c}}) | ||
| F | |||
| | |||
|- | |- | ||
| 2 | | 2 | ||
| Line 92: | Line 46: | ||
| 200 | | 200 | ||
| M2/d3 | | M2/d3 | ||
| 25/21 | | [[25/21]] (−9.2{{c}}) | ||
| F#, Gb | |||
| | |||
|- | |- | ||
| 3 | | 3 | ||
| Line 101: | Line 53: | ||
| 300 | | 300 | ||
| A2/P3/d4 | | A2/P3/d4 | ||
| 9/7 | | [[9/7]] (+3.8{{c}}) | ||
| G | |||
| | |||
|- | |- | ||
| 4 | | 4 | ||
| Line 110: | Line 60: | ||
| 400 | | 400 | ||
| A3/m4/d5 | | A3/m4/d5 | ||
| 7/5 | | [[7/5]] (+2.7{{c}}) | ||
| H | |||
| | |||
|- | |- | ||
| 5 | | 5 | ||
| Line 119: | Line 67: | ||
| 500 | | 500 | ||
| M4/m5 | | M4/m5 | ||
| 75/49 | | [[75/49]] (−5.4{{c}}) | ||
| | | H#, Jb | ||
|- | |- | ||
| 6 | | 6 | ||
| Line 128: | Line 74: | ||
| 600 | | 600 | ||
| A4/M5 | | A4/M5 | ||
| 5/3 | | [[5/3]] (−6.5{{c}}) | ||
| J | |||
| | |||
|- | |- | ||
| 7 | | 7 | ||
| Line 137: | Line 81: | ||
| 700 | | 700 | ||
| A5/m6/d7 | | A5/m6/d7 | ||
| 9/5 | | [[9/5]] (+6.5{{c}}) | ||
| | | A | ||
|- | |- | ||
| 8 | | 8 | ||
| Line 146: | Line 88: | ||
| 800 | | 800 | ||
| M6/m7 | | M6/m7 | ||
| 49/25 | | [[49/25]] (+5.4{{c}}) | ||
| | | A#, Bb | ||
|- | |- | ||
| 9 | | 9 | ||
| Line 155: | Line 95: | ||
| 900 | | 900 | ||
| A6/M7/d8 | | A6/M7/d8 | ||
| 15/7 | | [[15/7]] (−2.7{{c}}) | ||
| | | B | ||
|- | |- | ||
| 10 | | 10 | ||
| Line 164: | Line 102: | ||
| 1000 | | 1000 | ||
| P8/d9 | | P8/d9 | ||
| 7/3 | | [[7/3]] (−3.8{{c}}) | ||
| | | C | ||
|- | |- | ||
| 11 | | 11 | ||
| Line 173: | Line 109: | ||
| 1100 | | 1100 | ||
| A8/m9 | | A8/m9 | ||
| 63/25 | | [[63/25]] (+9.2{{c}}) | ||
| | | C#, Db | ||
|- | |- | ||
| 12 | | 12 | ||
| Line 182: | Line 116: | ||
| 1200 | | 1200 | ||
| M9/d10 | | M9/d10 | ||
| 25/9 | | [[135/49]] (+1.1{{c}}); [[25/9]] (−13.1{{c}}) | ||
| D | |||
| | |||
|- | |- | ||
| 13 | | 13 | ||
| Line 191: | Line 123: | ||
| 1300 | | 1300 | ||
| A9/P10 | | A9/P10 | ||
| 3/1 | | [[3/1]] | ||
| | | E | ||
|} | |} | ||
| Line 201: | Line 131: | ||
== 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>Equave stretch (¢) | |||
! colspan="2" | Tuning error | |||
|- | |||
! [[TE error|Absolute]] (¢) | |||
! [[TE simple badness|Relative]] (%) | |||
|- | |||
| 3.5.7 | |||
| 245/243, 3125/3087 | |||
| [{{val| 13 19 23 }}] (b13) | |||
| +1.393 | |||
| 1.150 | |||
| 0.79 | |||
|} | |||
=== Rank-2 temperaments === | |||
{| class="wikitable center-all right-3 left-5" | |||
|+ style="font-size: 105%;" | Table of rank-2 temperaments by generator | |||
|- | |||
! Periods<br />per tritave | |||
! Generator<br />(reduced) | |||
! Cents<br />(reduced) | |||
! Associated<br />ratio | |||
! Temperament | |||
|- | |||
| 1 | |||
| 1\13 | |||
| 146.30 | |||
| 49/45 | |||
| [[Procyon]] | |||
|- | |||
| 1 | |||
| 2\13 | |||
| 292.61 | |||
| 25/21 | |||
| [[Sirius]] | |||
|- | |||
| 1 | |||
| 3\13 | |||
| 438.91 | |||
| 9/7 | |||
| [[BPS]] | |||
|- | |||
| 1 | |||
| 4\13 | |||
| 585.22 | |||
| 7/5 | |||
| [[Canopus]] | |||
|- | |||
| 1 | |||
| 5\13 | |||
| 731.63 | |||
| 75/49 | |||
| | |||
|- | |||
| 1 | |||
| 6\13 | |||
| 877.83 | |||
| 5/3 | |||
| [[Arcturus]] | |||
|} | |||
== See also == | == See also == | ||
* [[Bohlen-p_et]] | * [[Bohlen-p_et]] | ||
* [[Catalog of 3.5.7 subgroup rank two temperaments]] | * [[Catalog of 3.5.7 subgroup rank two temperaments]] | ||
* [[No-twos subgroup temperaments#3.5.7 subgroup temperaments]] | |||
* [[19ed5|19ED5]]: relative ED5 | * [[19ed5|19ED5]]: relative ED5 | ||
* [[23ed7|23ED7]]: relative ED7 | * [[23ed7|23ED7]]: relative ED7 | ||
[[Category:Tritave]] | [[Category:Tritave]] | ||
[[Category:Macrotonal]] | [[Category:Macrotonal]] | ||
[[Category:Nonoctave]] | [[Category:Nonoctave]] | ||
[[Category: | [[Category:Bohlen–Pierce]] | ||
Latest revision as of 16:47, 22 May 2026
| ← 12edt | 13edt | 14edt → |

13 equal divisions of the tritave (13edt) is the nonoctave tuning system derived by dividing the tritave (3/1) into 13 equal steps of 146.3 cents each, or the thirteenth root of 3. It is best known as the equal-tempered version of the Bohlen–Pierce scale, and therefore has received by far the most attention among equal divisions of the tritave.
It provides an excellent approximation to the 3.5.7 subgroup, especially for its size, being comparable to 34edo's accuracy in the 5-limit. In this subgroup, it tempers out 245/243 and 3125/3087, the same commas as bohpier temperament. It is less impressive in higher prime limits, but makes for excellent no-twos 7-limit harmony. For higher limits, the multiples of 13 (26edt, 39edt, and 52edt) come to the fore.
13edt can be described as approximately 8.202edo. This implies that each step of 13edt can be approximated by 5 steps of 41edo.
In the no-2 3/1-equave-7-limit, 13edt maintains the smallest relative error of any EDT until 258edt and 271edt, and the smallest absolute error until 56edt.
Theory
| Harmonic | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 17 | 19 | 21 | 23 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | +0.00 | -6.53 | -3.83 | +0.00 | -54.80 | -51.40 | -6.53 | +69.39 | +23.14 | -3.83 | -15.02 |
| Relative (%) | +0.0 | -4.5 | -2.6 | +0.0 | -37.5 | -35.1 | -4.5 | +47.4 | +15.8 | -2.6 | -10.3 | |
| Steps (reduced) |
13 (0) |
19 (6) |
23 (10) |
26 (0) |
28 (2) |
30 (4) |
32 (6) |
34 (8) |
35 (9) |
36 (10) |
37 (11) | |
| Harmonic | 25 | 27 | 29 | 31 | 33 | 35 | 37 | 39 | 41 | 43 | 45 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | -13.07 | +0.00 | +22.59 | +53.44 | -54.80 | -10.36 | +39.74 | -51.40 | +8.32 | +72.17 | -6.53 |
| Relative (%) | -8.9 | +0.0 | +15.4 | +36.5 | -37.5 | -7.1 | +27.2 | -35.1 | +5.7 | +49.3 | -4.5 | |
| Steps (reduced) |
38 (12) |
39 (0) |
40 (1) |
41 (2) |
41 (2) |
42 (3) |
43 (4) |
43 (4) |
44 (5) |
45 (6) |
45 (6) | |
Intervals
| Steps | Cents | Hekts | Enneatonic degree |
Corresponding 3.5.7 subgroup intervals |
Lambda (sLsLsLsLs, E = 1/1) |
|---|---|---|---|---|---|
| 0 | 0 | 0 | P1 | 1/1 | E |
| 1 | 146.3 | 100 | A1/m2 | 49/45 (−1.1 ¢); 27/25 (+13.1 ¢) | F |
| 2 | 292.6 | 200 | M2/d3 | 25/21 (−9.2 ¢) | F#, Gb |
| 3 | 438.9 | 300 | A2/P3/d4 | 9/7 (+3.8 ¢) | G |
| 4 | 585.2 | 400 | A3/m4/d5 | 7/5 (+2.7 ¢) | H |
| 5 | 731.5 | 500 | M4/m5 | 75/49 (−5.4 ¢) | H#, Jb |
| 6 | 877.8 | 600 | A4/M5 | 5/3 (−6.5 ¢) | J |
| 7 | 1024.1 | 700 | A5/m6/d7 | 9/5 (+6.5 ¢) | A |
| 8 | 1170.4 | 800 | M6/m7 | 49/25 (+5.4 ¢) | A#, Bb |
| 9 | 1316.7 | 900 | A6/M7/d8 | 15/7 (−2.7 ¢) | B |
| 10 | 1463.0 | 1000 | P8/d9 | 7/3 (−3.8 ¢) | C |
| 11 | 1609.3 | 1100 | A8/m9 | 63/25 (+9.2 ¢) | C#, Db |
| 12 | 1755.7 | 1200 | M9/d10 | 135/49 (+1.1 ¢); 25/9 (−13.1 ¢) | D |
| 13 | 1902.0 | 1300 | A9/P10 | 3/1 | E |
JI approximation
Regular temperament properties
| Subgroup | Comma list | Mapping | Optimal Equave stretch (¢) |
Tuning error | |
|---|---|---|---|---|---|
| Absolute (¢) | Relative (%) | ||||
| 3.5.7 | 245/243, 3125/3087 | [⟨13 19 23]] (b13) | +1.393 | 1.150 | 0.79 |
Rank-2 temperaments
| Periods per tritave |
Generator (reduced) |
Cents (reduced) |
Associated ratio |
Temperament |
|---|---|---|---|---|
| 1 | 1\13 | 146.30 | 49/45 | Procyon |
| 1 | 2\13 | 292.61 | 25/21 | Sirius |
| 1 | 3\13 | 438.91 | 9/7 | BPS |
| 1 | 4\13 | 585.22 | 7/5 | Canopus |
| 1 | 5\13 | 731.63 | 75/49 | |
| 1 | 6\13 | 877.83 | 5/3 | Arcturus |
See also
- Bohlen-p_et
- Catalog of 3.5.7 subgroup rank two temperaments
- No-twos subgroup temperaments#3.5.7 subgroup temperaments
- 19ED5: relative ED5
- 23ED7: relative ED7