Hey man! This is my first post, but imma try to make it a useful one.
This isn't only directed to you, but also anyone else who's lookin to fatten up drums.
Learn how to EQ your drum sounds, and make sure they're all seperated when you track em out.
Start with the kick drum. Adding about 2-5 db at about 3-4K should bring out the drums initial attack. To clean up the muddiness of the kick remove some mids at around 300k. And it shouldn't be too overdone, but to boost the thump of the kick drum, adding about 4 db to the 60-80 Hz range should bring it out a bit.
EQing a snare drum on the other hand is a little different, considering there are millions of snare variations depending on tuning, the type of shell thats on the snare drum, the grittiness or quality of the sample, etc. For a little more crack and snap, boosting lightly in the higher frequencies, and reduction in the lows should help. This will all take some experimentation with different snares.
Hi Hats are significantly easier to EQ. for a crisp cutting sound, roll off the lower frequencies, and add some highs at about 10Hz. Or if you want a chunkier quality, add some high mids.
EQing drums takes some experimentation and patience so stick with it.
Another good useful technique to add some quality to your drums, would be layering. For instance, to thicken up a treble-filled clap sample, take a deep snare and layer it underneath the clap. That should thicken up the sound and give it a little more definition. The possibilities of drum layering are endless. It all depends on the sound you are shooting for.
Also, don't over compress your drum tracks. What i suggest is when you are at the mixdown process is, creating a stereo AUX input track. Assign a stereo bus input to your aux input track. Next take the outputs of your individual drum tracks, and send their outputs to the bus that your aux input track is picking up on. Now your drums should have the aux input acting as a 'sub-master fader'. On the aux input, apply a compressor to the insert, and compress your drum tracks. I usually allow no more than -6 db through the threshold, with a low ratio, and hard knee. This mixing technique is refered to as 'Parallel Compression'. Use it wisely.
You can even add a little reverb to fatten up the sound a little more, but not too much, because you to want to lose the attack of your drums. Drums can really get lost in reverb.
Thats all i have to offer for now. Hope you got something out of this!
KEEP IT VIBRANT!
-=ENIGMA=-