Irrational-subgroup temperaments: Difference between revisions

From Xenharmonic Wiki
Jump to navigation Jump to search
+ categories
Merge from photosynthesis; cleanup
 
Line 1: Line 1:
This page is a list of temperaments which have an irrational subgroup that cannot be expressed in surds.
This page is a list of [[regular temperament|temperaments]] of irrational subgroups that cannot be expressed in surds.
 
== Photosynthesis ==
Photosynthesis is a [[nonoctave]] temperament tempering out the comma 243/(5⋅ϕ<sup>8</sup>) in the ϕ.3.5 subgroup, equating five [[3/1]] with [[5/1]]. It has a period of [[acoustic phi]] and a generator of a major second just flat of 3/(ϕ<sup>2</sup>), the "phi-reduced 3rd harmonic". It possesses mos scales of the families 3L 1s<ϕ>, 4L 3s<ϕ>, 4L 7s<ϕ>, and 11L 4s<ϕ>.
 
[[Subgroup]]: ϕ.3.5
 
[[Comma list]]: 243/(5⋅ϕ<sup>8</sup>)
 
{{Mapping|legend=3| 1 0 -8 | 0 1 5 }}
: mapping generators: ~ϕ, ~3
 
[[Optimal tuning]]s:
* [[CTE]]: ϕ = 833.0903{{c}}, ~3/ϕ = 1057.989{{c}}{{confirm}}
 
[[Edφ|Edϕ]]s: 11, 15, 7[+5], 19[-5], 26, 5[--5], 18[+5], 23[-3, -5], 34[-3, -5], 37, 41[-3], 27[-3, -5], 49[-3, -5], 31[-3, --5]


== Polyraider ==
== Polyraider ==
The temperament below can also be written with [[34ed30]] nominals and cent-deviation (1\1171) accidentals. This temperament was found by [[User:2^67-1|2^67-1 (alias Cole Whitewood)]] in an attempt to figure out how to expand [[11edt]]'s approximations of this subgroup.


The temperament below can also be written with [[34ed30]] nominals and cent-deviation (1\1171) accidentals. This temperament was found by [[User:2^67-1|2^67-1 (alias Cole Whitewood)]] in an attempt to figure out how to expand [[11edt]]'s approximations of this subgroup.
[[Subgroup]]: 2.3.5.11.''f''<sub>2</sub>.''f''<sub>3</sub> *


[[Subgroup]]: 2.3.5.11.f2.f3 where ''f2, f3'' are the second and third modes of an ideal unsupported bar.
: <nowiki/>* ''f''<sub>2</sub>, ''f''<sub>3</sub> are the 2nd and 3rd modes of an ideal unsupported bar.


[[Comma list]]: [[1771561/1771470]], 1310730070806386550964611/1310720000000000000000000, [-8 6 -3 2 -1 0>, [-11 10 -7 4 0 -1>
[[Comma list]]: [[1771561/1771470]], 1310730070806386550964611/1310720000000000000000000, {{monzo| -8 6 -3 2 -1 0 }}, {{monzo| -11 10 -7 4 0 -1 }}


{{Mapping|legend=1|1 65 172 148 162 27 | 0 −111 −297 −253 −281 −43}}
{{Mapping|legend=1| 1 65 172 148 162 27 | 0 −111 −297 −253 −281 −43 }}
: mapping generators: ~2, ~10460353203/7040000000
: mapping generators: ~2, ~10460353203/7040000000


[[Optimal tuning]]s:  
[[Optimal tuning]]s:  
* [[WE]]: ~2 = 1199.999{{c}}, ~10460353203/7040000000 = 685.567{{c}}
* [[WE]]: ~2 = 1199.999{{c}}, ~10460353203/7040000000 = 685.567{{c}}{{confirm}}
: [[error map]]: {{val| -0.001 -0.001 -0.002 -0.017 -0.024 0.122 }}
: [[error map]]: {{val| -0.001 -0.001 -0.002 -0.017 -0.024 0.122 }}
* [[CWE]]: ~2 = 1200.000{{c}}, ~10460353203/7040000000 = 685.568{{c}}
* [[CWE]]: ~2 = 1200.000{{c}}, ~10460353203/7040000000 = 685.568{{c}}{{confirm}}
: error map: {{val|0.000 0.000 -0.001 -0.014 -0.023 0.125 }}
: error map: {{val|0.000 0.000 -0.001 -0.014 -0.023 0.125 }}



Latest revision as of 09:38, 17 October 2026

This page is a list of temperaments of irrational subgroups that cannot be expressed in surds.

Photosynthesis

Photosynthesis is a nonoctave temperament tempering out the comma 243/(5⋅ϕ8) in the ϕ.3.5 subgroup, equating five 3/1 with 5/1. It has a period of acoustic phi and a generator of a major second just flat of 3/(ϕ2), the "phi-reduced 3rd harmonic". It possesses mos scales of the families 3L 1s<ϕ>, 4L 3s<ϕ>, 4L 7s<ϕ>, and 11L 4s<ϕ>.

Subgroup: ϕ.3.5

Comma list: 243/(5⋅ϕ8)

Subgroup-val mapping: [⟨1 0 -8], ⟨0 1 5]]

mapping generators: ~ϕ, ~3

Optimal tunings:

Edϕs: 11, 15, 7[+5], 19[-5], 26, 5[--5], 18[+5], 23[-3, -5], 34[-3, -5], 37, 41[-3], 27[-3, -5], 49[-3, -5], 31[-3, --5]

Polyraider

The temperament below can also be written with 34ed30 nominals and cent-deviation (1\1171) accidentals. This temperament was found by 2^67-1 (alias Cole Whitewood) in an attempt to figure out how to expand 11edt's approximations of this subgroup.

Subgroup: 2.3.5.11.f2.f3 *

* f2, f3 are the 2nd and 3rd modes of an ideal unsupported bar.

Comma list: 1771561/1771470, 1310730070806386550964611/1310720000000000000000000, [-8 6 -3 2 -1 0⟩, [-11 10 -7 4 0 -1⟩

Mapping: [⟨1 65 172 148 162 27], ⟨0 −111 −297 −253 −281 −43]]

mapping generators: ~2, ~10460353203/7040000000

Optimal tunings:

error map: ⟨-0.001 -0.001 -0.002 -0.017 -0.024 0.122]
error map: ⟨0.000 0.000 -0.001 -0.014 -0.023 0.125]

Optimal ET sequence: 7, 1164, 1171, 1178, 1185, 2335, 2349, 3506, 3520, 3527, 4691

Badness (Sintel): 0.655