slightly off topic but may I offer some advice,,,?
you want to use 50 Hz. to fatten the kick drum.
It would be imperative to me if I were doing this (but I never would because there are much more natural better ways to fatten a kick) every drum is tuned and has a root pitch. Many drummers are good drummers but have never learned how to properly tune drums, but many have though, and regardless, the kick drum has a root pitch, and whatever that pitch is (that day or week) is the “exact” pitch you should use from your frequency generator if you want to proceeed with your way of fattening the kick.
Just my penny’s worth 🙂