Next up, we surgically remove the new noisemaker—that's alleged to be 50% louder, and maybe harder, better, faster?

Now that the microphone has migrated over near the digital crown, the speaker can take advantage of that space for more volume.

A silicone gasket seals the speaker to make its water-expelling magic possible, much like it did on last year's version.

The little black “eye” adjoining the speaker may be a barometric sensor, cleverly using the speaker grille’s access to the outside atmosphere. Since it no longer needs its own unsightly hole in the chassis as it did in Series 3, this is a victory for Jony Ives everywhere.

Update: It turns out there's a tiny tunnel from the air vent we saw in Step 3, passing through the chassis and right into the path of this little sensor. So it probably doesn't need any help from the speaker grille, but we still think it's most likely a barometer.