No wrote:
snip
I want to soundproof a room, where my wife can get some peace and
quiet from our son,
snip

The problem is not your wife, it is the noise. Don't isolate the
wife.

If you are unable or unwilling to change the noise from the son,
then provide sound proofing of a place for the son to make his
noise. How to do that depends on the type of noise and home
construction.
snip

Point source control (special absorption material) at the source
of the sound will also help.

snip

Point source control of the son!!!! That conjures up some interesting
images!!!

And I can think of plenty that should be used. :-)

--
Joseph Meehan

Dia's Muire duit