18edf: Difference between revisions
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== Theory == | == Theory == | ||
18edf corresponds to [[31edo]] with an [[octave stretching]] of about 9 [[cent]]s. Consequently, it does not provide 31edo's good approximations of most low harmonics, but it provides good approximations to many simple ratios in the thirds region: subminor [[7/6]] (+6{{cent}}), minor [[6/5]] (-3{{cent}}), neutral [[11/9]] (+4{{cent}}), major [[5/4]] (+4{{cent}}), and supermajor [[9/7]] (-6{{cent}}). These intervals may be used to form a variety of [[triad]]s and [[tetrad]]s in close harmony along with the tuning's pure fifth. | |||
In comparison, [[20edf]] (and [[Carlos Gamma]]) offers more accurate pental (minor and major) and undecimal (neutral) thirds, but less accurate septimal (subminor and supermajor) thirds. | |||
=== Regular temperaments === | |||
18edf is related to the [[regular temperament]] which [[tempering out|tempers out]] 2401/2400 and 8589934592/8544921875 in the [[7-limit]]; with 5632/5625, 46656/46585, and 166698/166375 in the [[11-limit]], which is supported by [[31edo]], [[369edo]], [[400edo]], [[431edo]], and [[462edo]]. | 18edf is related to the [[regular temperament]] which [[tempering out|tempers out]] 2401/2400 and 8589934592/8544921875 in the [[7-limit]]; with 5632/5625, 46656/46585, and 166698/166375 in the [[11-limit]], which is supported by [[31edo]], [[369edo]], [[400edo]], [[431edo]], and [[462edo]]. | ||
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== See also == | == See also == | ||
* [[31edo]] – relative edo | * [[31edo]] – relative edo | ||
* [[49edt]] – relative | * [[49edt]] – relative edt | ||
* [[72ed5]] – relative ed5 | * [[72ed5]] – relative ed5 | ||
* [[80ed6]] – relative ed6 | * [[80ed6]] – relative ed6 | ||
* [[87ed7]] – relative ed7 | * [[87ed7]] – relative ed7 | ||
* [[107ed11]] – relative ed11 | |||
* [[111ed12]] – relative ed12 | * [[111ed12]] – relative ed12 | ||
* [[138ed22]] – relative ed22 | |||
* [[204ed96]] – close to the zeta-optimized tuning for 31edo | |||
* [[39cET]] | * [[39cET]] | ||
[[Category:31edo]] |