245edo

From Xenharmonic Wiki
Jump to navigation Jump to search
← 244edo245edo246edo →
Prime factorization 5 × 72
Step size 4.89796¢ 
Fifth 143\245 (700.408¢)
Semitones (A1:m2) 21:20 (102.9¢ : 97.96¢)
Consistency limit 5
Distinct consistency limit 5

245 equal divisions of the octave (abbreviated 245edo or 245ed2), also called 245-tone equal temperament (245tet) or 245 equal temperament (245et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 245 equal parts of about 4.9 ¢ each. Each step represents a frequency ratio of 21/245, or the 245th root of 2.

245edo is only consistent to the 5-odd-limit. The equal temperament tempers out [-17 21 -7 and [19 10 -15 in the 5-limit; 6144/6125 and 16875/16807 in the 7-limit; 441/440, 4000/3993, 6912/6875, 14700/14641, 30375/30184 and 54675/54208 in the 11-limit.

Odd harmonics

Approximation of odd harmonics in 245edo
Harmonic 3 5 7 9 11 13 15 17 19 21 23
Error Absolute (¢) -1.55 +0.63 +0.97 +1.80 +2.15 +1.92 -0.92 -2.10 +1.26 -0.58 -1.34
Relative (%) -31.6 +12.8 +19.8 +36.8 +43.9 +39.2 -18.8 -42.8 +25.8 -11.8 -27.3
Steps
(reduced)
388
(143)
569
(79)
688
(198)
777
(42)
848
(113)
907
(172)
957
(222)
1001
(21)
1041
(61)
1076
(96)
1108
(128)

Subsets and supersets

Since 245 factors into 5 × 72, 245edo has subset edos 5, 7, 35, and 49.