If adding many soundproofing elements to your door seems like too much work try adding an acoustic door panel.
Soundproof door panel.
While closed doors do a decent job shutting out the noise outside the room cracks between a door and its casing or threshold offer just enough space for some sound to filter in.
You can also coat the door with sound absorbing paint which can reduce external noise by nearly 30.
To soundproof a door install a curtain rod over the back of the door and get a heavy fabric drape to hang from the rod.
Soundproofing doors is easier when you understand the acoustics involved.
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.
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.
If you are willing to change your doorframe to a metal one then this is a very effective door sealing method which will make a huge difference to the sound resistance of your door.