DIY vs BUY - Soundproofing
Door Soundproofing
Probably needless to say this is was a clear DIY situation for me. Sound proof door retail solutions are extremely expensive and the do it yourself option gets the job done fine with a cost that ranges from inexpensive to plain dirt cheap. I am sure that there are slightly more affordable retail product options out there, but come on... That money will certainly be of better use in other areas. I am assuming that you have a good solid wood door though. It is probably a fair assumption that none of you are currently using a bamboo or cloth curtin for a studio door, but there are certainly plenty of crappy hollow doors hung in the doorframes of the world.
Rubber weatherstripping all the way around the door stop was a quite effective sound barrier for me. (Make sure it is a rubber product and NOT FOAM) Run it along the door stop right at the edge of where the door jam meets the stop. Be careful not to stretch it as you stick it in place. It will eventually shrink back down and leave uncovered areas where sound can leak in.
I have built two different wedge inserts to fill the space beneith the door. The key to the effectiveness of your floor wedge is sound reflective / absorbtive materials and a good tight fit. Ideally you will fill the entire space beneith the door and provide an overlapping airtight (or as close as possible) seal between the door, frame and floor. My first floor wedge was made out of left over acoustic closed cell foam, and the second out of the left over acoustic fiberboard wrapped in a high density rubber acoustic barrier material. Originally I thought that the foam based wedge would simply be replaced by the heavy duty new acousic board/barrier insert. I have since found that high and mid frequencies are best canceled out by the closed cell foam construction. (IE tv noise, most music, talking) The low end noises are best cancelled out by the heavier acoustic board and barrier wedge. (IE open window road noise, household appliances, bass music, heavy object moving.) So now I just use the one that best works for the given situation.
Construction / Seal 
Floor Plugs
