soundproof a door

I just returned from checking the new offices my coworkers and I will be moving to. It looks like I'm being put into a room that was "soundproofed" for recording reasons. There's a large double paned window between my room and the outer offices with glass that's about 1/2" thick each. When I rapped on it, it felt like my knuckles were hitting granite. Solid and quiet. The entry wasn't anything special except for a solid core door that seemed very heavy. Whether this room is soundproof or not is yet to be tested, but I think Richard is correct that replacing a hollow core door with a solid one would be a good step. Your bi-fold could get expensive though.

A solid core is better of course, but unless it's 3 inches thick and totally sealed when you close it you won't really accomplish much. Funny thing that sound, it's always gettin in somebody's ears.

I have built sliding panels similar to pocket doors. It would have to hang inside your room. If you want, email me and I'll explain and send you some pics.

Larry

Maybe you could build a couple of gobos (short for 'go-between', a portable partition used when recording to prevent sound leakage between adjacent microphones) to fit in your doorway while you are listening to music that can be rolled away to another part of the room when not in use. You could fill them with fiberglass and put acoustical tile on the surface. Let your wife decorate them to fit in with the decor.
Just a thought.

I disagree that your Solid core door needs to be "3 inches thick and completely sealed". You can get a decent STC rating (probably around 55-60) with a regular stock solid core door, and full gasketing all around. Use gasketing from the autoparts store for car doors, and you'll be fine. Trying to get an STC rating above that in a residential environment is fairly ridiculous, and would involve a triple layer, triple sealing multi-thickness monstrosity.

Be sure to gasket around the floor as well, or use a neoprene buffer.

Hueske, I think you are right but also that a solid door even if gasketed will much satisfy someone in the next room. I think his only real answer is to find another room.