The crossfader is the horizontal slider on a DJ mixer or controller that blends between your left and right decks. To use it, you slide it toward whichever deck you want the audience to hear — centre means both, fully left or right means one. Learning how to use a crossfader well is about timing that movement and choosing the right curve for the job.
Here is what the crossfader does, when to reach for it, and when to leave it alone.
What the crossfader does
Every DJ mixer routes its channels to a crossfader. Assign deck A to the left side and deck B to the right, and the crossfader controls the balance between them:
- Full left: you hear only deck A.
- Centre: you hear both decks at full volume.
- Full right: you hear only deck B.
It sits alongside the vertical channel faders, which control each deck’s volume independently. Understanding both is part of knowing what a DJ mixer actually does.
Crossfader curves explained
Most mixers and software let you change the crossfader curve, which sets how quickly the volume changes as you move the slider:
- Smooth (gentle) curve: volume fades gradually across the whole travel. Ideal for long, blended transitions in house and techno.
- Sharp (fast) curve: the channel reaches full volume after only a tiny movement. This is what scratch DJs use, because it lets a quick flick cut the sound in and out.
You will find the curve adjustment on the mixer itself or in your software settings in Serato DJ Pro, rekordbox or Traktor Pro. Set it to match what you are doing that night.
Using the crossfader for blends
For a standard transition between two beatmatched tracks:
- Start with the crossfader fully on the playing track.
- Make sure both tracks are tempo-matched and beat-aligned — see beatmatching if that is new to you.
- Slowly move the crossfader toward the incoming track over several bars.
- Use EQ along the way so two basslines never play at once.
- Once the new track is carrying the energy, push the crossfader fully across.
This is the backbone of mixing two songs together, and pairing crossfader moves with EQ is what makes a blend sound clean rather than muddy.
Crossfader vs channel faders
Plenty of DJs blend using only the vertical channel faders and leave the crossfader in the centre or unassigned. Both approaches work:
- Channel faders give you independent control of each deck and feel natural for long, smooth blends.
- The crossfader is faster for quick cuts and is essential for scratching, where you need sharp, one-handed in/out control.
Many house and techno DJs barely touch the crossfader, while turntablists live on it. Neither is more “correct” — choose the tool that fits your style.
The crossfader for scratching
For scratch routines, the crossfader becomes a rhythmic instrument. With a sharp curve, you cut the sound on and off in time with your hand movements on the platter. This takes practice and clean gear, but it is the foundation of techniques like the cut and the chirp. If that interests you, start with our beginner’s guide to scratching.
Practical tips
- Know your “off” sides. Make sure you have assigned each deck to the correct side before a set, or your crossfader will fade the wrong way.
- Watch for worn faders. An old crossfader can crackle or cut out near the edges. Many mixers, like Pioneer DJM and Allen & Heath Xone models, use replaceable contactless faders for this reason.
- Practise smooth, even moves. A jerky crossfade is obvious to the crowd. Aim for steady, controlled travel.
Frequently asked questions
Do I have to use the crossfader to DJ?
No. Many DJs blend entirely with the channel faders and only use the crossfader for scratching or quick cuts. It is a useful tool, but not mandatory for smooth mixing.
What is crossfader lag or cut-in?
Cut-in is how far you have to move the crossfader before sound appears on the other side. A sharp curve has almost no cut-in, which scratch DJs want; a smooth curve eases in gradually. It is set by the crossfader curve.
Why does my crossfader sound crackly?
Usually a worn or dirty fader. On mixers with replaceable contactless faders, swapping the unit fixes it. Keeping gear clean and dust-free also helps the crossfader last longer.
