Almost surely phase related...
The OP mentions that the sound coming off the overheads sounds good/balanced.
With the OH mics playing, add the snare close-mic track (nothing else while trouble-shooting).
If the sound doesn't get fuller (or gets weaker), then there's phase cancellation going on.
You can resolve this several different ways.
- Quick way is to try using a phase switch (which will change the phase 180 degrees).
- There are also plugins that allow exact adjustment of phase (not just 180 degrees)
- You can also zoom in and manually (visually) align the phase of the snare track with the overheads. Since the snare mic is closer than the overheads, it's signal will be a littler earlier. Drag it back to where the waveform phase aligns with the overheads.
Phase related issues are common when using multiple mics at different distances.
Drum kit is an obvious example... with room, overheads, and clock mics.
The Overheads are much more distant from the snare and toms than the close mics... so it would be common for them to initially be out of phase. With careful mic placement (overheads), you can minimize/avoid this issue.
Google search for "3:1 mic placement".
Add one drum mic at a time... making sure the new track is in phase (sound gets bigger/fatter).
Once all mics are in phase, the overall drumkit should sound pretty decent.
If you're working in modern pop/rock/country, I'd suggest routing the individual drum tracks to a Drum Subgroup.
On this drum subgroup, apply a bit of "bus compression". The SSL Bus Compressor is perfect in this application.
Gives the drumkit more "weight/umph" without making it sound overly squashed.
Be careful with compression on cymbals. Too much... and the cymbals sound unnatural.
IMO, The key to getting good acoustic drum sounds starts with the overheads.
If the overheads sound good... you've got a solid foundation on which to build.
If the overheads don't sound good... I'd recommend re-positioning and re-recording.