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.
Sound proofing panel on door.
Foam insulation tape self adhesive weather stripping for doors and windows sound proof soundproofing door seal weatherstrip cooling air conditioning seal strip 1in x 3 8in x 16ft black.
Use these panels to block sound leaking through any rectangular or squared opening.
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.
If adding many soundproofing elements to your door seems like too much work try adding an acoustic door panel.
Excellent for windows doors and openings.
Soundlock a lightweight sturdy and convenient acoustical sound dampening panel loaded with high density insulation enhanced with either 1lb or 2lb density mass loaded vinyl to reduce sound transmission.
To soundproof a door make it structurally strong enough to block noise by replacing it with a solid core door or by adding mass loaded vinyl soundproof blankets and panels to the existing door.
Then seal the gaps with a door gasket door sweep or spray foam to prevent air leaks.