It seems that sound pickup is different with dvx than dsr or beta using the same
mics. When using dvx my wireless neckmic and the dinamic mic are picking up
much more ambient sound than with shoulder cams. Is this possible?
ALC on the DVX is a limiter, and won't impact the amount of signal that comes into the camera. The Mic Gain setting really just depends on how hot the mic is. If you have a mic that isn't as hot and needs a little boost, set to -60dB.
The mics aren't going to pick up any more sound than they would with other cameras. The difference may be in the pre-amps or in how you've set up your gain staging.