Effects & processing
Beat FX
Beat FX are the effects section on a DJ mixer that locks its timing to the detected tempo. Every delay, echo, roll and gate is set in beat divisions rather than in milliseconds, so one setting stays musical across records.
In practice
Beat FX are only as accurate as the tempo they read — a wrong BPM puts every division fractionally off the grid.
Tap the tempo in or set it manually rather than trusting an auto reading on anything with an unusual pulse: half-time bass music and anything with a swung or broken beat are where automatic detection is least reliable, and where a beat-locked effect goes wrong most audibly. Learn the divisions you actually use — a half beat, a beat, a bar — rather than the whole list, and set the wet level before you engage rather than after.
1/2, 1, 4
The divisions that earn their place
From the BPM
Where the timing comes from
Set wet first
Before you engage
Where these come from: Mixer conventions and effect practice, not catalog figures. We publish the tempo we detect for each track, and a detector can count a different pulse from the one you hear — which is exactly the input a beat-locked effect depends on. For what we can measure, see what each division works out to in milliseconds.
Why it matters
The whole section rests on one number. A mixer reading the tempo converts your beat division into a time on every record, which is what lets a 1/2-beat setting stay right when you change track — and what makes every effect land off the grid the moment the tempo it read is wrong.
That dependency is worth knowing because the failure is silent. A delay set to a half beat against a tempo the mixer has misread does not sound broken, it sounds slightly wrong, and the natural response is to blame the record rather than the reading.
Frequently asked
How do Beat FX work?+
They read the track’s tempo and express every effect time as a fraction or multiple of a beat, so a 1/2-beat delay is automatically the right number of milliseconds on whatever record is playing.
Why do my Beat FX sound off?+
Usually because the mixer has read the wrong tempo. Beat-locked timing is exact arithmetic on a number that may itself be wrong, and half-time detection on bass music is where it goes wrong most often.
Which Beat FX are actually useful?+
Delay, echo and filter cover most of what a transition needs. The rest of the list is worth knowing about and rarely worth reaching for mid-mix.
Related terms
Delay
Delay repeats a sound after a set time. On a DJ mixer that time is locked to the detected tempo, so the setting is a beat division rather than a number of milliseconds and the repeats land on the grid.
Beatgrid drift
Beatgrid drift is a grid that lines up at the start of a track and slides out of alignment later — the tempo the software stored is close to the real one but not equal to it.
Sync
Sync matches one deck’s tempo to the other automatically and holds it there, using the beatgrid the software calculated. It removes the arithmetic of beatmatching, not the decision about which record follows which.
Colour FX
Colour FX are the per-channel effects on the knob above each channel — filter, noise, crush, echo. Centred is off; turning either way engages the effect on that deck alone.
Explore: BPM tapper · Beats-to-time calculator · Mixing guides · All DJ terms