How humans hear sub-bass?
When you are designing (or mixing) audio you have to keep in mind the final consumer. Who's going to listen to this song? In what environement, what device, what file etc.
This is even more important when you are mixin g bass heavy track or genre. Humans can hear from approx 20Hz up to 20kHz. The majority of usefull spectrum is somewhere along 40Hz to 12kHz. This is what early days of MP3 was based on. Just eliminiate sound on the edges of our hearing.