Ah great, thank you mate. The mystery is solved :-) I figured that the pressure lock would help increase the base dB so it wasn't actually a bad thing. Just wasn't sure whether chewing could damage the driver by putting _too_ much pressure on it. Guess not. Thanks for your reply Music Alchemist.

I have a question about something that's been bugging me for months. I was just too lazy to signup on the forums prior.   Is it normal for the SR-009 (or any electrostatic headphone for that matter) to pop while I'm eating or chewing with the headphones on? I would guess the SR-009 fit so well...