User:Eliora/1ed81/80: Difference between revisions

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Created page with "'''81/80s equal temperament''' (AS81/80) is an equal multiplication of the syntonic comma. It corresponds to 55.79763 EDO. == Theory == 81/80s equal temperament can be re..."
 
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'''81/80s equal temperament''' (AS81/80) is an equal multiplication of the [[syntonic comma]]. It corresponds to 55.79763 EDO.
{{todo|merge articles|inline=1|text=Merge into [[81/80]] and/or [[56edo]]? (in a "[[stretched and compressed tuning]]s" section)}}
{{Infobox ET|1ed81/80}}
 
'''1 equal division of 81/80''' ('''1ed81/80'''), also known as '''ambitonal sequence of 81/80''' ('''AS81/80''') or '''81/80 equal-step tuning''',  is an equal multiplication of the [[syntonic comma]]. It corresponds to 55.79763 edo. It is almost exactly [[80edn]].


== Theory ==
== Theory ==
81/80s equal temperament can be regarded as a subset of 5-limit just intonation.
{{Harmonics in equal|1|81|80|columns=11}}


Some intervals it approximates well are [[5/4]], [[7/4]], [[12/11]], [[14/13]], and [[15/11]]. In addition, it represents well certain compound intervals such as [[8/3]], [[11/1]], [[12/1]] while omitting their octave reductions.  
1ed81/80 can be regarded as a subset of 5-limit just intonation. Some intervals it approximates well are [[5/4]], [[7/4]], [[12/11]], [[14/13]], and [[15/11]]. In addition, it represents well certain compound intervals such as [[8/3]], [[11/1]], [[12/1]] while omitting their octave reductions. With a stretch, [[53edo]] can be regarded as its edo equivalent. However, the closest direct approximation is [[56edo]].


With a stretch, [[53edo]] can be regarded as its ED2 equivalent.
AS81/80 has a good representation of the 11.17.19 prime number subgroup. This time, the octave equivalence is not applied.

Latest revision as of 14:11, 1 August 2025

Todo: merge articles

Merge into 81/80 and/or 56edo? (in a "stretched and compressed tunings" section)

← 0ed81/80 1ed81/80 2ed81/80 →
Prime factorization n/a
Step size 21.5063 ¢ 
Octave 56\1ed81/80 (1204.35 ¢)
Twelfth 88\1ed81/80 (1892.55 ¢)
Consistency limit 2
Distinct consistency limit 2

1 equal division of 81/80 (1ed81/80), also known as ambitonal sequence of 81/80 (AS81/80) or 81/80 equal-step tuning, is an equal multiplication of the syntonic comma. It corresponds to 55.79763 edo. It is almost exactly 80edn.

Theory

Approximation of harmonics in 1ed81/80
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +4.35 -9.40 +8.70 +9.50 -5.05 +7.66 -8.45 +2.70 -7.65 -0.60 -0.70
Relative (%) +20.2 -43.7 +40.5 +44.2 -23.5 +35.6 -39.3 +12.6 -35.6 -2.8 -3.2
Step 56 88 112 130 144 157 167 177 185 193 200

1ed81/80 can be regarded as a subset of 5-limit just intonation. Some intervals it approximates well are 5/4, 7/4, 12/11, 14/13, and 15/11. In addition, it represents well certain compound intervals such as 8/3, 11/1, 12/1 while omitting their octave reductions. With a stretch, 53edo can be regarded as its edo equivalent. However, the closest direct approximation is 56edo.

AS81/80 has a good representation of the 11.17.19 prime number subgroup. This time, the octave equivalence is not applied.