256/225

256/225, the diptolemaic diminished third or Neapolitan diminished third, is the interval that results from stacking two 16/15 minor seconds. It is sharp of the Pythagorean diminished third by two syntonic commas, hence the first name, whereas the second name comes on account of this interval occurring in precisely this manner in Neapolitan scales.

Interval information

Ratio	256/225
Factorization	28 × 3-2 × 5-2
Monzo	[8 -2 -2⟩
Size in cents	223.4626¢
Names	diptolemaic diminished third, Neapolitan diminished third, marvel 5-limit subharmonic second
Color name	sgg3, sagugu 3rd
FJS name	[math]\displaystyle{ \text{d3}_{5,5} }[/math]
Special properties	reduced, reduced subharmonic
Tenney norm (log2 nd)	15.8138
Weil norm (log2 max(n, d))	16
Wilson norm (sopfr(nd))	32
[sound info]
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It is a marvel comma (225/224) flat of the subharmonic second, 8/7, and so tempering out 225/224, which is marvel temperament, equates the two. As such, it can also be called the marvel 5-limit subharmonic second. It is also 5632/5625 sharp of 25/22.

See also

• 225/128 – its octave complement
• Gallery of just intervals