While different songs needs different kick drum sounds, most of the time the producer looks to feature the drum's most appealing characteristics: a booming low-end and a clean attack. The kick's inherent ugliness, where it sounds "boxy," resides around 500hz. Sometimes it's closer to 400hz.

Luckily there is parametric EQ that allows you to specify the bandwidth, because in this case a really narrow bandwidth will allow you to cancel out the most unpleasant frequency without affecting the rest. Start at 500hz, and take it all out.Suddenly, the kick sounds a lot rounder. After you've decided which frequency to focus on - look at the range of 400-550hz - dial some of it back in if the sound you've achieved is unnatural. This is a useful trick because some instruments have a certain frequency that's so inherently ugly you can simply cut of it all.