The Kick Drum Main Three: BOOM, SMACK, CLICK…
These are three key elements that can be used to describe the sound of a kick drum.
Boom is where the low end thud of the kick drum comes from. Nowadays in modern music, this range is found around the 50-60Hz area. A more traditional, ringing boom will be found a bit higher, in the 100Hz range. Typically a peaking band is used for the boom but you can experiment with a low shelving band here if your kick drum is lacking girth. Be careful not to overdo it with the shelf as things can get blurry fast in the sub frequency ranges.
Smack is the primary attack of the kick drum. This is the frequency range that helps the ear identify individual kick drum hits.
Ben Vesco says, “I like to start my search for smack in the 3-5kHz range. Microphones specifically tailored to kick drums will often have a bit of a presence bump somewhere in this range. I always use a peaking band for the smack and keep the Q parameter in the 1 to 1.5 range.”
Click is exactly what you think it is. At first thought you might not attribute click as a quality desired in a kick drum sound. Click works along smack to help bring a kick drum through a dense mix. This is the sound of the beater actually hitting the drum head. You can find the click around the 6-8kHz range. A peaking band works well on the click (Q around 1.5) but a high shelf can be used to enhance the bleed of the snare wires in the kick drum mic.
Mud is not one of the big three because it is a bad thing! We want the opposite of mud in our mix, especially on the kick drum. You can remove some of the mud and clean up your kick drum sound by cutting a thin band in the 250-300Hz range.
Alternative, Better Methods?
Although I do like the above method, I tend to mix my kick drums slightly different. Instead of using additive or "enhancement" equalization first, I start right at the problem sources by using subtractive eq. So instead of removing that Mud frequency at the end... I tend to take it out first. And sometimes you don't even need to subtract that frequency! But other times you may find yourself needing to take out more than expected. Always trust your ear and test out your adjustments in the final mix.
After removing "Mud", I search for other problem areas. Maybe a hiss or snare bleed at 5k-20k. Yes a big range! But the truth is, anything can come from anywhere. And by notching out small areas within that range, you've created a much cleaner kick drum! I tend to not over do it, and only take out enough so that the naked ear can't detect unwanted noise.
After I apply my desired compression using either analog or a digital plugin, I will then apply my "enhancement" or additive eq. The reason why I want to apply compression first is so that my levels are consistent. This will help both with hearing a consistent eq change and will also eliminate the problem of bad frequencies becoming amplified and good frequencies becoming inconsistent if the chain was reversed.
My go to plugins are analog emulated parametric EQ's!