Soundproofing doors is easier when you understand the acoustics involved.
Soundproofing door panel.
If adding many soundproofing elements to your door seems like too much work try adding an acoustic door panel.
Acoustic door blanket panels overlap the door and extend beyond the frame to prevent acoustical leaks.
Owens corning paintable white fabric square 48 in.
Sound absorbing acoustic insulation wall panels 2 pack model 02520 view the owens corning sound absorbing acoustic panels.
These panels offer a step up from gluing a sheet of plywood to your door but they re not generally as expensive as high end solutions like fiberglass soundproofing blankets.
Then seal the gaps with a door gasket door sweep or spray foam to prevent air leaks.
They have a cut out for the door handle slits to fit around the hinges and velcro sewn onto the back for quick and easy installation.
Magnetic door gaskets only work on doors which are built into metal frames so they aren t a suitable method of soundproofing for most doors.