LOW
Low EQ
The knob on the EQ that boosts or cuts the low band. What is in it is almost entirely the kick and bass, which form the foundation of a track. The sound gets muddy when the low ends of two tracks play at once, so when mixing you lower the LOW on one and raise it on the other, swapping which one is the lead. This is the operation most often used in a DJ's mixing.
What lives in the LOW
The LOW covers the lowest band of the sound. In dance music this is mainly the kick and the bass, which make up most of the "boom" and "wub" you feel in your body.
Turn the LOW down and the track sounds lighter, as if it were playing far away. Turn it up and the sound gets thicker and comes forward. DJs use this change to switch which of the two tracks takes the lead.
Using the LOW in a mix
The basic shape goes like this. ① With the next track's LOW turned down, raise its channel fader to overlap it. ② At the end of a phrase, turn down the playing track's LOW and turn up the next track's LOW. ③ Lower the playing track's fader to take it out.
The LOW swap in ② can be done all at once or gradually. Swapping all at once makes the change clear-cut; doing it gradually gives a long mix where you cannot tell where one track ends.
Why you should not raise both LOWs at once
When the kicks and basses of two tracks play at the same time, the low end piles up and gets much louder all at once. The speakers cannot take it cleanly and the sound turns muddy, and the level meter easily goes into the red zone. On top of that, the two bass lines clash and neither track comes through clearly.
So the basic rule of mixing is that the LOW is up on only one track at a time. Always being aware of which track has its LOW up prevents the mistake of muddy sound.