Pilot announcement PA quality On a recent passenger flight my son asked me, "How come we're able to build a 737 for \$50M - \$80M with fantastic reliability and technology but can't design a PA system so that we can understand the pilot's announcements?" Many are quite un-intelligible but the cabin crew announcements generally are intelligible. I didn't have a good answer. Does anyone know?

As a follow on and of more concern, if pilots' microphone technique / equipment is so poor then how does air-traffic control understand them? I know there is a limited vocabulary set and that standard phrases are used to avoid mis-hearing but there must be some problems.
Many pilots prefer to use their headset boom mic or hand mic instead of the dedicated interphone handset for PA announcements. 

I don't know why, but I know from personal experience that the dedicated interphone handset has much better PA readability.