22/15 |1 -1 -1 0 1>
663.0492 cents
https://en.xen.wiki/w/File:Jid_22_15_pluck_adu_dr220.mp3 sound sample
The undecimal diminished fifth of 22/15 is flat of 3/2 by 45/44, and is the interval between 5/4 and 11/6.