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.
It helps to think of the curve as the relationship between physical movement and audible change. On a smooth curve, the middle third of the fader’s travel does most of the work, so small wobbles in the centre barely affect the mix — perfect when you want a transition to breathe over thirty seconds or more. On a sharp curve, almost all of the volume change is packed into the first few millimetres at each edge, so the fader behaves like a switch with a tiny grey area in between. If you are unsure which to pick, start in the middle and adjust only once you know whether the night calls for long blends or quick cuts.
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 how you EQ mix as a DJ is what makes a blend sound clean rather than muddy. Master both and your DJ transitions will sound far more polished.
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.
How to choose a crossfader curve for the job
The right curve depends almost entirely on what you are trying to achieve in that moment, so it is worth knowing how to match the setting to the task rather than leaving it on the default forever:
- Long blends in house, techno or disco: reach for the smoothest curve, or skip the crossfader and ride the channel faders instead. You want gradual change with no abrupt jumps.
- Cutting between drops or quick double-drops: a medium-to-sharp curve lets you snap across on the downbeat without a noticeable fade.
- Scratching and turntablism: the sharpest curve available, so a tiny flick of the wrist gives a clean on/off cut.
- Open-format and party sets: a medium curve is a safe all-rounder, fast enough to cut yet forgiving enough to blend.
If your mixer has a curve knob rather than a software setting, get into the habit of checking it at the start of a set. Picking up a borrowed or club mixer mid-night with the curve set for the previous DJ’s scratch routine is a common way to ruin a smooth blend.
Common crossfader mistakes
A few habits trip up newer DJs more than anything else. Avoid these and your transitions will sound far more deliberate, and they appear on most lists of common DJ mistakes to avoid:
- Moving the fader too fast. A rushed slide drops the new track in before the crowd is ready. On a beatmatched blend, let the move take several bars.
- Forgetting to use EQ. Pushing two full-range tracks together with the crossfader alone leaves two basslines fighting. Cut the bass on the outgoing track as you bring the new one in.
- Leaving a deck assigned to the wrong side. If your assign switches are set up backwards, the crossfader fades toward silence instead of your incoming track.
- Ignoring the curve setting. Trying to blend on a curve set for scratching produces an abrupt jump no matter how slowly you move.
- Resting your hand on the fader. Idle pressure can nudge it off-centre and quietly drop one deck’s level. If you are not using it, leave it parked at the correct edge.
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.
- Mind the fader’s “feel”. Some crossfaders have adjustable tension or reverse switches. A looser fader suits scratching, while a firmer one resists accidental knocks during blends.
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.
Should I scratch and blend with the same curve setting?
Rarely. Scratching wants the sharpest curve so a flick cuts the sound instantly, while blending wants a smooth curve so the fade is gradual. If you do both in one set, get used to switching the curve, or blend on the channel faders and reserve the crossfader’s sharp setting for scratch sections.
