Analog wizard Eric Schlaepfer send me this great video of a Neumann microphone being built. You even get a little of a hot tub being vacuum formed at the end. I love Discovery Channel. Now I want to see “How it’s made, in China” to see how they do the cheap knock-offs. Eric noted:

It's very interesting how they mount the diaphragm. It looks like the plastic film is mounted in tension on the hoop when they place it on the brass capsule part. I imagine they also vacuum deposit the gold electrode while the film is tensioned on the hoop.