I believe your question has been answered many times already in this very thread, as well as many other places. A quick search for "subbass", "sub-bass" or "sub bass" will help.
From my own experience, I can say that it's in the "good" territory. The HyperX/Cloud to my ears have a fluid bass, okay texture, a bit on the bassy side. My DT880 has less bass quantity but can reach lower, my Sr325is bass punches harder but has less sub bass. When listening to EDM, most of the time I will boost 3-5 dbs below 90 Hz.
This is my current Equalizer APO (with PEACE GUI) settings for the HyperX Cloud:
Only peaks cutting:
With bass boost: