HYP difficulty go up and down in diapason 700-1500 because of low retarget window (30 blocks).
di·a·pa·son
/ˌdīəˈpāzən,ˌdīəˈpāsən/
noun
1.
an organ stop sounding a main register of flue pipes, typically of eight-foot pitch.
2.
a grand swelling burst of harmony.