As mentioned before, this is sometimes applied during the pre-master stage. However, mastering engineers have a habit of taking care of these things should the mixer/producer is not aware of this process. Using a high pass filter at 30Hz and a low pass filter at 19kHz will ensure that the frequency spectrum has been capped at the top and bottom preventing any frequencies from being generated by the speaker system.
Mastering - Roll-off Filters
Updated: Dec 21, 2020