870edo

From Xenharmonic Wiki
Jump to navigation Jump to search
← 869edo 870edo 871edo →
Prime factorization 2 × 3 × 5 × 29
Step size 1.37931¢ 
Fifth 509\870 (702.069¢)
Semitones (A1:m2) 83:65 (114.5¢ : 89.66¢)
Consistency limit 7
Distinct consistency limit 7

870 equal divisions of the octave (abbreviated 870edo or 870ed2), also called 870-tone equal temperament (870tet) or 870 equal temperament (870et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 870 equal parts of about 1.38 ¢ each. Each step represents a frequency ratio of 21/870, or the 870th root of 2.

870edo is notably strong in the subgroup of Fermat primes, 2.3.5.17.

As an equal temperament, 870et tempers out [-53 10 16 (kwazy comma) in the 5-limit; 250047/250000 and 2100875/2097152 in the 7-limit, supporting pnict. In the 11-limit it tempers out 12005/11979 and provides the optimal patent val for the corresponding rank-4 temperament.

Odd harmonics

Approximation of prime harmonics in 870edo
Harmonic 2 3 5 7 11 13 17 19 23 29 31
Error Absolute (¢) +0.000 +0.114 -0.107 -0.550 +0.406 -0.528 -0.128 +0.418 -0.688 -0.612 -0.208
Relative (%) +0.0 +8.3 -7.7 -39.9 +29.4 -38.3 -9.3 +30.3 -49.9 -44.3 -15.1
Steps
(reduced)
870
(0)
1379
(509)
2020
(280)
2442
(702)
3010
(400)
3219
(609)
3556
(76)
3696
(216)
3935
(455)
4226
(746)
4310
(830)

Subsets and supersets

Since 870 factors into 2 × 3 × 5 × 29, 870edo has subset edos 2, 3, 5, 6, 10, 15, 29, 30, 58, 87, 145, 174, 290, and 435.

Icon-Stub.png This page is a stub. You can help the Xenharmonic Wiki by expanding it.