Define "blowy." The Sennheiser G2 and G3 systems come with both an 1/8" and an XLR cable. The problem might be that the output level on your receiver is set too high. I'm not sure, but I think the HMC40 lets you manually control the mic level as well. On the DVC30 you push and hold the Menu button until the audio menu pops up, then y ou can override the AGC and set the levels manually.
The HMC40 does have audio gain control......in the menus. For anything but ambient, the HMC40 is pretty useless for audio without the XLR adapter.
It's to bad they didn't put audio gain switches for the onboard or 1/8" plug on the flip out instead of zoom. It would have helped a little. Who uses zoom on the flip out anyway?