I am trying to get in the X-12 Research Center. I am on the top level but there is a force field blocking my entry. I have no idea how to get in. I checked the wiki about some kind of emiter, but I don't understand, since it doesn't explain it. I tried shooting it with my Sonic Emitter- Revelation, but nothing is happening.

So what am I suppose to do? I just don't get it. I am blind and I don't see any clues either.

Can anyone help me please?

You have to upgrade the Sonic Emitter first by going through the tests at the X-8 Research Center. This is part of the main quest line.

After you've upgraded it, use it to drop the force field.