Firstly everybody would tell you to have a minimalistic approach towards EQ-ing and to cut rather than to boost. They would say that subtractive EQ avoids adding unnecessary gain to the signal and such. But by doing so, you might need to increase the volume of the instrument you’re working on, because cuttings are essentially lowering the gain.
That was the first tip, and now there are a few frequency ranges that you should pay attention to.
Usually you’d like the kick drum to have both a thick bass thump from the low-end and a driving click from the mids. So to add some extra weight (that is low-end punch or bottom depth), boost at 50-150 Hz. Don’t overdo it as it can clutter up the low-end. And don’t boost the extremely low frequencies as this will mostly cause a muddy sound. If possible, use bell mode on the EQ to better isolate the frequencies.
To reduce boom, or tighten and clean up the low-end in general, set a high-pass filter around 50-60 Hz. (20 Hz and below only adds unnecessary energy to the total sound.)
If the kick drum needs more body, boost some in the 90-120 Hz range.
Apply cut somewhere in the 150-600 Hz range to treat muddiness, while boxiness is most prominent near 400 Hz. Also apply a notch filter at 250 Hz, that can add thump or slap attack to the kick drum.
Push between 2-4 kHz to add attack, and also boost a bit between 4-7 kHz to make the kick drum snappy.
Remove extreme high (for a kick drum you shouldn’t need anything over 10 kHz) and low frequencies (at least kill everything below 20 Hz) with a high- and a low-pass filter.
You can, more or less, use the the same tips as for the kick drum above with a few changes and additions.
Cut at 80 Hz to remove rumble.
If the snare sounds thin, boost at 125-150Hz for a little weight and a full snare sound. And to give the snare some punch, boost around 250 Hz.
The body of the snare should be around 500 Hz, adding there will give a rounder sound.
Boost around 2 kHz for some crispy edge and add at 2.5 kHz for extra snap and attack. Also add clarity and even more punch by boosting around the 3 kHz area.
You might want to give the snare some air and presence by raising somewhere between 6-15 kHz, like at 10 kHz.
Hand claps and rim shots can mostly be treated as snares.
For the floor tom that needs low-end fulness, add some at 80-100 Hz, and for the smaller rack tom lift somewhere closer to 250 Hz.
Increase thump and add attack around 250 Hz.
Cut the mids around 400 Hz to reduce boxiness.
Add attack by boosting between 4-7 kHz (depending on the size of the tom).
Hihats and Cymbals
When you’re done mixing the volume level of the hihats, you usually don’t really have to boost or cut anything. Still, the clank or gong sound is around 200 Hz, but if you want definition, then roll off everything below 500-600 Hz using a high-pass filter. By doing so, you clear out low-end information that is nonessential for the hihat.
If the hihat is sounding thin, boost around 400-800 Hz.
Cut at 1 kHz to remove jangling, and treat clangy sounds by cutting between 1-4 kHz.
A small boost with a wide Q at the 3 kHz range will add presents to the hihat.
Add brightness and get sizzle by lifting at 10 kHz. And if the sound is too harsh, then make a high-shelf cut around 16 kHz.
That’s it. Next time I’ll guide you through the creation of synthesized drums.
Note: processing sampled sounds can turn hihats pretty harsh, therefore use a de-esser to affect the problem frequencies without messing with the overall volume or clarity.