the only way to SOUNDPROOF, not to be confused with Sound treatment, is Isolation, Density and Air-tightness. the frequency range thats probably giving you problems are below 300Hz with an occasional loud hit that's higher in frequency. these are virtually impossible to tame in normal house construction. in my basement i have a 10 floor to floor height with a 8ft suspended ceiling and with R19 (6inches thick) laying on top of the Ceiling. this helped some and especially with room modes, but to actually get soundproofing i'd need to build a room within a room.
be sure you don't confuse Soundproofing with Sound Treatments.