Mass and seperation.
Filling the core of the door with insulation will absorb sound passing through the doors hollow core, but if the door does not have much mass then I don't think it will do much.
30mm of foam, can't see it making a huge difference, and you are bound to leave hollow gaps within the door and you still have a low density frame.
I think low frequency noises will be much less affected by this type of soundproofing.
The devil is in the detail, it may be a brilliant acoustic insulator, but at what thickness and in what situation?
What is the price of foam in a can to for a doors worth, £15, a few cans?
Filling the core of the door with insulation will absorb sound passing through the doors hollow core, but if the door does not have much mass then I don't think it will do much.
30mm of foam, can't see it making a huge difference, and you are bound to leave hollow gaps within the door and you still have a low density frame.
I think low frequency noises will be much less affected by this type of soundproofing.
"the foam is an excellent thermal and acoustic insulator that sticks to practically all building materials."
The devil is in the detail, it may be a brilliant acoustic insulator, but at what thickness and in what situation?
What is the price of foam in a can to for a doors worth, £15, a few cans?