Reference
Console manual
Warmup is a two-deck DJ console that runs in your browser. It plays audio files from your computer, analyses their tempo and key, and gives you the controls found on club equipment. The Academy teaches you how to use them in order. This manual is the reference for every control.
Setting up
Speakers
Plug speakers or headphones into your computer's headphone socket, or connect by USB. The console plays through whichever output your operating system has selected. Click anywhere on the page once to switch the audio on. Avoid Bluetooth speakers and headphones for practice: they delay the sound by a tenth of a second or more.
Your music
Press Add files or Add folder in the Library, or drag files onto the page. MP3, WAV, FLAC, M4A/AAC and OGG work in most browsers. Files stay on your computer.
Tempo and key are worked out in the background as soon as you add files, so you can sort by BPM or key straight away. The browser cannot keep your files between visits, so the library list is empty after a reload. Add the same folder again and the console recognises each file: beat grids, keys and hot cues come back at once.
Fits now filters the library to tracks within 6% of the playing deck's tempo and in a matching key. The small percentage under each BPM is the tempo change that track would need.
Twenty-two tracks are built in, from 82 to 174 BPM: house, deep house, tech house, disco, techno, trance, UK garage, breakbeat, afro house, reggaeton, synthwave, trap, lo-fi, hip-hop and drum and bass. They are generated in your browser, so they need no download. They have clean phrases, exact beat grids and known keys, and they are mastered at different loudness on purpose.
Headphone cueing
Choose an Output mode in the mixer:
- Speakers only. Master in stereo. Channel Cue buttons have no audible effect.
- Split cue. Left channel carries the headphone bus in mono, right channel carries the master in mono. Wear headphones, or use a DJ splitter cable to send the right side to speakers and the left side to headphones.
- 4-channel interface. Outputs 1-2 carry the master, outputs 3-4 carry the headphones, both in stereo. Available when your audio device offers four or more outputs and is the system output.
Microphone and MIDI permission
On the website and in the downloaded warmup-dj-console.html file, the browser asks for permission the first time you connect an audio input or a MIDI device. Allow it and the device appears. MIDI needs Chrome or Edge on a computer. Inside the Claude artifact viewer both are blocked, so use the website or the downloaded file for instruments and controllers.
Signal flow
The Cue tap sits before the fader, so you can hear a channel in headphones while its fader is closed. The FX send sits after the fader and crossfader, so effects only process what the audience hears, and their tails keep ringing when you close a fader. The Live channel bypasses the crossfader.
Decks
| Play / Pause | Starts and stops the deck with a short ramp. Pressing Play during a Cue preview keeps the track running. Shift + Play on a playing deck gives a slow vinyl brake. |
|---|---|
| Cue | Paused away from the cue point: stores a new cue point. Paused on it: hold to preview. Playing: stops and returns to it. A loaded track is cued to its first beat. |
| Sync | Matches this deck's tempo to the other deck, aligns the beats if it is playing, and keeps following while lit. Moving the tempo fader turns it off. Locked in Ear mode. |
| Tempo fader | Down is faster, up is slower. Double-click to return to zero. Hold Shift while dragging for fine control. The range button cycles ±8%, ±16% and ±50%. With Key lock off, tempo changes pitch, as on a turntable. |
| Key lock | Holds the track's original key while the tempo changes. It sounds cleanest within about ±8%. Scratching, reverse and the start and stop ramps always behave like vinyl. With Key lock off, the Key readout shows the pitch shift in semitones. |
| Beat lights | Four lights under the overview step through the bar, with beat 1 in white. The line beside them shows the bar, the phrase, and how many bars remain until the next phrase. It turns pink for the last two bars. |
| − / + | Pitch bend. Hold to slow down or speed up by 4% (10% with Shift) to line the beats up. Release to return to the set tempo. |
| Jog wheel | Vinyl on: drag the platter top to scratch, drag the outer ring to nudge. Vinyl off: the whole wheel nudges. While paused, the wheel moves the playhead for fine positioning. |
| Slip | The track keeps its place silently during scratches and loops. On release, playback jumps to where it would have been. |
| Quant | Cue points, hot cues, loop edges and hot cue jumps snap to the beat grid. |
| Rev | Hold to play backwards. On release the track rejoins where it would have been. |
| Loop row | In and Out set loop edges by hand. Auto starts a loop of the size shown, from the current beat, and exits it when pressed again. ½ and ×2 change the size from 1/32 beat to 64 beats, before or during a loop. Reloop / Exit leaves the loop, or re-enters the last one. |
| Pads: Hot cue | Empty pad stores a position. Lit pad jumps to it. Shift + pad deletes. Hot cues stay with the track for the session. |
| Pads: Loop | Auto loops from ¼ beat to 32 beats. Press the lit size again to exit. |
| Pads: Roll | Momentary loop from 1/16 beat to 8 beats with slip. Release to rejoin. |
| Pads: Jump | Move by ±1, ±4, ±16 or ±64 beats without losing time. An active loop moves with you. |
| Overview | The whole track. Click or drag to move the playhead. Pink ticks mark 16-bar phrases, the amber line is the cue point, coloured marks are hot cues. |
| Beat grid tools | Tap tempo, shift the grid by 5 ms, halve or double the BPM, or set bar 1 at the playhead. Use these when the analysis of your own file is off. |
| Time | Click to switch between time remaining and time played. It turns red in the last 30 seconds. |
Reading the big waveforms. The white line is now. Sound to its right is coming. Blue is bass, amber is mids, white is highs. Thin lines are beats, tall lines are bars with their number, pink P flags are 16-bar phrases. Both waveforms scale with tempo, so when two decks are matched their beat lines sit one above the other. The phase strip between them shows the gap in milliseconds.
Mixer
| Trim | Input level, ±12 dB. Set it so the channel meter peaks at the 0 line. |
|---|---|
| Hi / Mid / Low | Three-band EQ. Centre is flat, right adds up to 6 dB, fully left removes the band almost completely. |
| Filter | One knob, two filters. Left of centre is a low-pass (removes highs), right is a high-pass (removes lows). Centre is off. |
| Cue | Sends the channel to the headphone bus. |
| Channel fader | Volume of that channel in the master. |
| Crossfader | Blends A and B. Smooth curve for blends, sharp curve for cuts and scratching. |
| Master level | Overall output. CLIP lights when the mix overloads before the limiter. |
| Phones Cue/Mst | Blend of cue bus and master in the headphones. Fully left is cue only. |
| Meters | Green is safe, the white line is 0, amber is hot, red is too hot. |
| Knobs and faders | Drag up and down. Hold Shift for fine steps. The mouse wheel and arrow keys also work. While you turn a knob its label shows the value. Double-click resets one control. “Reset trims, EQ and filters” resets all of them. |
Effects
One FX unit, five effects. Choose the effect, set the time in beats, light the channels it should process, set Depth, and press FX on. Switching FX off closes the input and lets the tail ring out.
- Echo. Tempo-locked repeats with feedback. Time is the spacing between repeats.
- Ping-pong echo. The same, with repeats alternating left and right.
- Reverb. A large room. The beats setting has no effect.
- Flanger. A slow jet sweep. Time is the length of one sweep in bars.
- Phaser. A softer, hollow sweep at the same rate.
Live channel
The middle mixer strip, labelled Live, carries the sampler, the keyboard instruments and the audio input.
- Sampler. Eight one-shot pads in two banks. Club FX holds drums and effects. Vocals holds eight sung one-shots, rendered in the followed deck's key when you open the bank. Shift + pad loads your own sound file.
- Beats. A 16-step drum machine with kick, clap, hat and percussion rows. It locks to the beat grid of the deck you choose and follows its tempo, loops and jumps. When that deck is stopped it runs free at the deck's tempo. Twelve ready-made patterns and three kits (Club, 808, Live) are in the two menus. Your pattern is remembered. The Metronome button adds a click on every beat, higher on beat 1.
- Keys. Seven instruments: piano, electric piano, plucked guitar, bass, synth lead, pad and organ. Play with the mouse, a touchscreen, the computer keyboard (press Keys in the top bar) or a MIDI keyboard. Dots mark the notes of the followed deck's key. The large dot is the home note.
- Live input. Any microphone or instrument through your computer's audio input. Gain sets the level and Drive adds distortion.
- MIDI. Connect to play the instrument from a MIDI keyboard. Learn maps any knob, fader or button of a MIDI controller to any console control. Mappings are remembered in this browser.
Voice
The Voice tab puts a vocal on the Live channel in three steps: choose a source, tune it, loop it.
Source
- Built-in singer. A synthetic voice that needs no microphone. Pick a song and press Sing. It starts on the next bar, sings in the key of the deck you follow, and stays in time with it through loops and jumps. The lyrics light up word by word. Tuned steps cleanly between notes, Natural adds vibrato and slides, Robot sings on two notes with the Electrify effect.
- Your own words. Type up to eight short lines. Each line is sung over two bars on a built-in melody. Words outside the singer's dictionary are pronounced by spelling rules, so some come out wrong.
- Your microphone. Any microphone the browser can see, including a laptop's built-in one and a headset. It works on the website and in the downloaded file. Wear headphones: a live microphone near speakers feeds back.
Tune and effects
| Tune | Pitch correction. The voice is pulled to the nearest note of the chosen key and scale. The strip shows how far off the incoming note is, and the letter shows the note it is being moved to. |
|---|---|
| Follow / Key / Scale | Take the key from Deck A or B, or set one by hand. Key scale uses all seven notes, Pentatonic uses the five safest, Any semitone only removes drift between notes. |
| Speed | How fast the voice is pulled onto the note. Instant gives the hard, stepped sound. Around 50 ms sounds natural. |
| Amount | How much of the correction is applied. 100% lands exactly on the note. |
| Harmony | Adds one or two extra voices above or below, chosen from the scale. The knob sets their level. |
| Electrify | A resonator tuned to the note being sung. It gives the metallic, charged edge of a talk-box. |
| Sound buttons | Clean, Hard tune, Choir and Robot set the knobs to four useful starting points. |
Looper
Choose a length, press Record loop, and recording starts on the next bar of the followed deck. When the bars are up the take plays back in time and keeps looping. It records whatever the Voice section is producing: you, the singer, or both. If the tempo changes, the loop follows by playing faster or slower. Timing shifts the recording to cancel your computer's audio delay. Copy to pad 8 puts the take on the sampler.
Mix report
The Report tab scores each blend out of 100. A blend starts when both decks are audible and ends when one is gone. Overlaps shorter than four beats are treated as cuts and are not scored.
| Part | Points | What is measured |
|---|---|---|
| Beats | 45 | Share of the blend with the two beat grids within 25 ms of each other |
| Bass | 20 | Time with both LOW knobs up and both decks clearly audible. The first beat or so is free. |
| Phrasing | 15 | 15 if the 8-bar blocks of both tracks lined up, 8 if only the bars did |
| Clipping | 10 | Times the master lit CLIP during the blend |
| Level | 10 | Change in master level from before the blend to after it |
Beats and phrasing rely on the beat grids, so check the grid on your own tracks first. The report reads the controls and the grids. It does not listen to the audio, so it cannot hear a bad track choice or a key clash.
Keyboard shortcuts
| Action | Deck A | Deck B |
|---|---|---|
| Cue (hold to preview) | Z | N |
| Play / Pause | X | M |
| Sync | C | , |
| Pitch bend − / + | A S | K L |
| Auto loop, halve, double | Q W E | U I O |
| Pads 1 to 4 | 1 2 3 4 | 7 8 9 0 |
← → move the crossfader. Shift is the console Shift. R starts and stops recording. T taps in drills. ` switches Keys mode, where A to ; play white keys, W E T Y U O P play black keys, and Z X change octave.
Limits
- Key lock is a simple time-stretch. It is clean for small tempo changes. Beyond about ±8% you will hear a slight flutter on sustained sounds and softer kicks.
- Beat grids and keys for your own files are estimates. Steady electronic music analyses well. Live drummers, tempo changes and long beatless intros can confuse it. Tempos below 88 or above 176 BPM are reported doubled or halved, so use the ÷2 and ×2 buttons.
- A mouse is slower than hardware. You can move one control at a time. A touchscreen allows two hands, and a mapped MIDI controller removes the limit.
- The singer is a synthesiser. It sounds like a tuned robot voice, with clear vowels and rough consonants. It will not pass for a person.
- Pitch correction follows one voice at a time. It works on singing and on single-note instruments. Chords, and a microphone that also hears the speakers, confuse it. Expect about 15 ms of delay on the corrected voice.
- Recordings are saved as compressed WebM or MP4 audio.
- Streaming services cannot be loaded. Only audio files you have on your computer.
- Memory. Each loaded track uses roughly 20 MB per minute. Very long files, such as a two-hour mix, may not load.
Troubleshooting
| No sound | Click the page once. Check the chip in the top bar says the engine is running. Then follow the signal flow: trim, channel fader, crossfader, master, Output mode, and the computer's own volume. |
|---|---|
| Sound in one ear only | Output is set to Split cue. Switch to Speakers only when you are not using headphones for cueing. |
| Controls feel slow | Close other heavy tabs and programs. On a slower computer the console draws the waveforms at half rate by itself to keep the controls responsive. Zooming the waveforms in also lightens the load. |
| Crackles or dropouts | Close other tabs and programs. If the top bar shows “Compatibility engine”, the browser refused the low-latency engine. A current Chrome or Edge will use it. |
| Beat lines sit off the kicks | Open Beat grid tools on that deck and shift the grid, or pause on the first kick and press Set bar 1 here. |
| BPM shows half or double | Press BPM ×2 or ÷2 in Beat grid tools. |
| A file will not load | The browser cannot decode it. Protected files from streaming or old store purchases will not play. Convert to MP3 or WAV. |
| Microphone or MIDI blocked | Click the padlock or site-settings icon in the address bar, allow Microphone or MIDI devices for this site, and reload. MIDI needs Chrome or Edge. Inside the Claude viewer both stay blocked. |
| Keys feel late | Use wired headphones or speakers, and a USB audio interface if you have one. |