A lot of it boils down to the materials you are recording, in addition to the mic technique you are using. If you could describe a specific example, we can give you more specific advice.
In general, creating "large" impact sounds involves a balanced combination of techniques including:
- layering contrasting sound elements
- layering different microphone perspectives of the same sound
- filling out the frequency spectrum (mid and high frequencies are just as important as low energy)
- judicious use of compression, limiting and EQ
It sounds like you have a good setup. If you have another mic sitting around, I would recommend double-miking your recordings. Try to put the second mic in a second position that "hears" a totally different performance than the schoeps. Record a couple takes with the mics in a close position, then record the same sounds with the mics a bit further back, but still contrasting each other.
In your DAW, experiment with using the sharp punch of the close-miked sounds in combination with the distant recordings. It's actually very similar to recording a drum kit in a way. The close-mics on each drum are not enough to faithfully reproduce the true sound of the kit—you need some room mics to add in the interaction of the drums with the room and give each drum it's natural, tonal decay. I often find myself lightly (or heavily) compressing room mics to exaggerate the presence of the room.
Hope this helps!