Tony Maserati's approach to mixing bass often involves a combination of a low-cut filter and a low-end boost.
The boost adds weight and presence to the bass, while the low-cut filter is applied to remove excessive sub-bass frequencies. This technique results in a fuller, more controlled bass sound, enhancing the low end while maintaining clarity.
In this particular instance, he is boosting at 50-60Hz and filtering at around 20Hz.