In a modern pop production, the drums are almost always crisp and tight. Mixing them the right way provides a solid foundation for the rest of the elements. Flimsy loose drums bring down the energy and usually make the song sound dull. Before processing the drums, it is important to make sure that the samples you choose are appropriate for the kind of music you are producing and are of good quality. If you are tracking a drummer play live, make sure that you get a good recording before you start working on mixing/production.
Depending on the genre, drums are treated and processed in different ways. In a lot of hip hop music, the kicks have a lot of thump but the sub bass frequencies are taken off to make space for the low sub bass, which is characteristic of that genre. In heavy metal, the kicks are quite clicky to make them cut through all the guitars and cymbals. Similarly, snares, hats, and other percussions, though used across several styles of music, have their own distinct characteristic sound based on the context in which they are used. This can be achieved by processing the sound in different ways.
In any song which has drums and a bass, one of the first things to do is to take off the fundamental frequencies of the kick from the bass and vice versa. This avoids frequency clashes and makes the bass and kick sit together. In EDM since the kick and bass are so big, just attenuating the frequencies using EQ isn’t always enough. Sidechain compression on the bass with the kick prevents the bass from overpowering the kick, and creates the signature ducking effect.
The sidechain compressor’s attack and release settings must be modelled based on the ADSR envelope of the kick. Attack and release settings should be on the faster side and the compressor should be active only when the kicks are being triggered. If the compressor allows too much room, the kick will not be able to fill the gap and the ducking effect creates an empty hole in the sound. If the ducking is too little, the kick frequencies will begin to clash with the bass. Many modern productions outside of the EDM genres extensively use sidechain compression without making the ducking effect apparent. This can help you get a crisp, clean and tight sound.
To make the drums snappier and push through the other layers, a common trick is to compress them with medium to slow attack and fast to medium release. Essentially, this results in the transients being left uncompressed (because of the slower attack) and the rest of the body being compressed. This creates a tight, snappy sound.
Having processed individual samples of kicks, snares, hats and other percussions, the next logical step would be to send all these elements to a drum bus. Further compression, EQ and reverb applied on this drum bus can make your drums sound more cohesive.
Scooping the mids out of the drums often helps in creating more space for other elements. It also makes them sound crisp. This may not work the same way with all samples and all recordings, but attenuating the frequencies of the main elements of the song from the drums is a good idea to not make the mix sound cluttered.
One of the ways to blend the drums with the rest of the elements is to send them to a reverb. If the drums and some of the other elements of the song have a little bit of reverb it helps the music feel cohesive. A good reverb unit with appropriate settings (predelay, decay time, etc) and send level on different elements glues them all together. This way, any vocals on top of these elements can also have quite a bit of reverb without sounding too wet or out of place. In some cases, even insert reverbs help to create a sense of space and depth in the mix. Only thing to watch out for is the cluttering up of frequencies because of the reverb. An EQ, and maybe even a compressor on the reverb AUX track helps a lot in making the mix sound clean.
Similarly, sending elements of the song through a distortion or saturation unit brightens them up and brings them together. Depending on the unit, this process makes the tone brighter and can also compress and EQ it at the same time. Alternatively, high frequency content can be boosted using an exciter. This can make your drums sound more airy. In rock and metal songs, the guitars, vocals, and drums can be brought together by sending them to amps and other distortion and saturation units in different amounts. However, use saturation a
nd distortion judiciously as sending too much changes the tone of the element quite drastically and it may start to stick out of the mix. Tone and transient shaping using EQ and compression makes the drums feel like they are part of the same family as the rest of the elements.
However, drums may not always need to sound tight and crisp. In various genres of music, drums are way back in the mix, just adding to the feel of the song. In such a case, they should blend well into the mix and not be too prominent. Since the transients contain most of the high frequencies, one way to blend them with other elements is to shelve out the highs. This, however, usually ends up in making the drums sound filtered and dull. A more transparent way of achieving this effect is through a compressor. Since the high frequencies of the drum are mostly in the transients, they can be subdued if the compressor only ducks the transients and leaves the rest of the body uncompressed. A high threshold, high ratio, fast attack and fast release helps in pushing the drums back into the mix.