2. 80 Hz
The standard THX subwoofer crossover frequency is 80 Hz.
The 80Hz is best suited to
- high enough to release the much-needed bass on midbass speakers, leading to the creation of "bookshelf"-sized speakers that fit well with the general impressions about the size of acceptable speakers;
- is not so high that conventional bass drivers have a reaction problem due to inductance;
- and low enough that the sub is still difficult to place in place.