Mixing

This is the core product manual: how mixr actually mixes. Read this once and you’ll understand what mixr is doing during your set and when (if ever) you need to step in.

The model: queue, then sit back

mixr is not a “pick a deck, drop a track, load the next one” app. It’s an autoplay-from-queue app.

You queue tracks. mixr loads the first one onto Deck A and starts playing it. As that track approaches its mix-in point, mixr preloads the next queued track onto Deck B, picks a transition, and rides the crossfader from A to B over a beat-locked 8-, 16-, 32-, or 64-bar window. When the crossfade finishes, Deck B becomes the “playing” deck and the next queued track preloads onto Deck A. The cycle repeats until you stop it or the queue runs dry.

Two implications worth keeping in mind:

• You don’t pick which deck a track goes on. mixr does that. Deck A is always physically on the left of the dashboard and Deck B is always on the right, but which one is playing swaps every mix.
• There is always one playing deck and (usually) one incoming deck. The “incoming” deck is preloaded and silent until the crossfade begins. You can preview, EQ-prep, or hot-cue the incoming deck without disturbing the main output.

You steer this model in two ways: quick controls (transport, jump, force-mix-now, force-transition) for the common 95% case, and hand control via the Mixer overlay for the rest.

Queueing tracks

There are four ways to fill the queue.

Browse the Beatport catalog (b key). Press b from the dashboard to open the full browse view. Drill into Genres, pick a genre, drill into Top 100 or Charts or Releases, and press Enter on a track to queue it. Press a (lower-case) to queue every track on the current screen at once — handy for top-100 lists.

Search (/ or s). Type an artist or track name, press Enter, browse the results, queue with Enter or a.

Your own library. Once you’ve pointed mixr at your local music folder via Settings → Library → Local Library Directory, Local Library appears at the bottom of the browse root. It opens as a folder tree — each level has its own tracks and a trailing ⇲ All tracks (recursive) row that flattens the subtree. The same Settings → Library section accepts rekordbox XML, Engine DJ databases, and Serato databases.

Beatport playlists, charts, your favorites, your cart. Browse into My Beatport, My Library, or Favorites and queue from there the same way.

Once you’ve queued anything, the dashboard becomes the place to be. Press d to return to it.

A few queue management keys worth knowing:

| Key | What it does | |---|---| | q | Open the queue view | | a | Queue all on the current screen | | x | Smart shuffle the queue (BPM + key aware) | | X | Clear the queue (Y/N confirm) | | { / } | Grab a queue row and drop it elsewhere — reorders | | L | Load Next — replaces the incoming track with the highlighted one |

The transport

These are the four keys you’ll use during every set.

| Key | What it does | |---|---| | p | Play / pause the currently-playing deck | | n | Skip — abandon the playing deck, swap to the next queued track immediately | | m | Mix now — start the crossfade right now, don’t wait for the mix-in point | | t | Teleport — fast-forward the playing deck to its mix-in point |

m and t are the two you’ll reach for most often. t is for “I’m done with this track, get me to where the mix happens.” m is for “actually, start the mix this instant.”

A couple of secondary transport keys:

| Key | What it does | |---|---| | < / > | Jump back / forward by N bars on the playing deck (N from Settings → Jump Bars, defaults to 16, cycles 4/8/16/32) | | [ / ] | Nudge the incoming deck slightly slower / faster (manual phase fix) | | ; / ' | Shift the beat grid ±2 ms | | ( / ) | Shift the beat grid ±1 beat (the big one — when the analyzer put the grid on the off-beat) | | T | Rewind last mix — pull the previous track back to start a do-over | | B | Bail — force the current crossfade to EchoOut and salvage it |

Crossfading

mixr starts a crossfade automatically when the playing track gets within crossfade_bars of its mix-out point. The fade is beat-locked: it begins on a downbeat and the per-sample volume curves are equal-power (constant total loudness through the blend).

The bar count — how long the fade lasts — comes from Settings → Crossfade Bars, and you can pick 8, 16, 32, 64, or Auto. Auto adapts per-mix based on the genre and tempo of the two tracks (longer for melodic / techno, shorter for DnB / breaks). 16 bars is a good default for most styles.

The dashboard tells you what’s coming. Above the crossfader you’ll see a MIX IN N bars countdown — that’s how many bars of the source track remain until the crossfade kicks off. The line below it shows the chosen transition type plus the BPM gap and Camelot key distance between the two tracks.

If you want a different fade length than the global setting for just this one mix, open the command prompt with : and type:

:crossfade 32

…then Enter. Note: that changes the global setting; this is mostly useful when you want to flip between two values quickly.

The five transitions

mixr picks one of five transition types for each mix. The choice is automatic — based on the BPM gap and Camelot key distance between playing and incoming — but you can override it at any time.

BeatMatched

Equal-power crossfade with phase-locked beat sync. Cosine-shaped on the way out, sine-shaped on the way in — the loudness stays constant through the blend. The classic, safe DJ transition; incoming deck rides on a phase-corrected rate so the beats land on top of each other.

Picked when: BPMs match (≤ 8% apart, or a 2:1 / 1:2 ratio) and the key distance is ≥ 3 (or unknown).

EchoOut

A hard cut on the outgoing deck plus an echo / delay tail that rings out for ~8 bars, while the incoming deck enters dry under the decay. Sonically it’s a “drop out and slam in” — useful between tracks that don’t beat-match cleanly, because nothing needs to phase-lock.

Picked when: the BPM gap exceeds 8% (or 14% with pitch stretching enabled). Always 8 bars regardless of your crossfade_bars setting — it’s a cut, not a fade. EchoOut is also what B (bail) and Auto-Bail train-wreck recovery fall back to.

BassSwap

Both decks play at full volume through the middle of the mix, but the EQ lows are killed on the incoming deck until the midpoint, at which point the lows on the outgoing deck drop and the incoming bass slams in. A drop-swap moment — works in harmonically-related tracks where doubling the mids/highs sounds musical, not muddy.

Picked when: BPMs match and Camelot key distance is 0–1 (same key or one step on the wheel).

FilterSweep

The outgoing deck sweeps from bypass up to a high-pass filter (progressively losing bass), while the incoming deck sweeps from a low-pass (only bass) up to bypass. They meet in the middle — the outgoing track gets thinner as the incoming track gets brighter.

Picked when: BPMs match and Camelot key distance is 2 — a small mood shift where you want a smoother transition than BassSwap.

LoopRoll

The outgoing deck enters a 4-beat loop at the crossfade start, which stalls it in place while the incoming track fades up over the full bar count. The loop is released at ~85% of the way through so the playing deck has runway to fade out cleanly. Useful when the outgoing track is running out of song before the crossfade window completes.

Picked when: never automatic. Set it explicitly with :transition looproll.

Forcing a transition type

Three ways:

• Command prompt: : then transition beatmatched / echoout / bassswap / filtersweep / looproll (or shortcuts beat / echo / bass / filter / loop).
• IPC: {"transition":"echoout"} written to ~/.mixr/command.
• Disable a transition entirely in Settings → Transitions — rows for each of the 5 types, on/off — and mixr will skip it when picking.

For deeper control over when a given transition fires, see the Transition Rules editor under Settings — first-match rules keyed on BPM gap, key distance, mix count, and previous transition.

Manual control — the Mixer overlay

m triggers a crossfade. B bails one. t teleports. But when you want to ride the EQs and filters yourself — kill the bass on the incoming deck, sweep the playing track’s highs out — you want the Mixer overlay.

Press z or Z to open it. The overlay shows EQ Low / EQ Mid / EQ High / Filter / Fader for one deck at a time.

Keys inside the overlay:

| Key | What it does | |---|---| | Tab | Swap between Deck A and Deck B | | ↑ / ↓ | Move between rows (EQ Low → EQ Mid → EQ High → Filter → Fader) | | ← / → | Adjust the focused row’s value | | r | Reset the focused row to its default | | 0 | Reset every row on every deck (Y/N confirm) | | Esc / z / Z | Close the overlay |

EQ ranges from −24 dB (kill) to +12 dB (boost) per band. Filter is a single-knob design: −1.0 is fully low-pass, 0 is bypass, +1.0 is fully high-pass. Fader is the per-deck channel volume, 0 to 1.

The crossfader and channel faders are on the dashboard

The Mixer overlay covers per-deck tone and volume. The crossfader, channel faders, tempo faders, hot cues, play/pause and jump/nudge buttons all live on the Controller panel of the dashboard itself.

To drive them from the keyboard: press Tab from the dashboard until Controller is focused (it’ll light up in cyan). Now ↑ / ↓ cycle through the controls (tempo A, volume A, cue A, play A, jump A, nudge A, EQ/filter A, crossfader, EQ/filter B, nudge B, jump B, play B, cue B, volume B, tempo B). ← / → adjust the focused control.

Or use the mouse — click and drag any control. The crossfader bar in particular is click-and-drag along its full width.

Preview / cue

Press Space on a track in browse, search, queue, or history to preview it. The preview plays through the monitor bus only — if you’ve set up a separate monitor device (Settings → Monitor Device), it goes to your headphones. If not, the preview shares the main output.

To stop the preview, press Space again.

For previewing the incoming deck during a live mix (without disturbing the main mix), enable Split Cue with S. With split cue on, the monitor bus sends Deck A to your left headphone and Deck B to your right — you can hear what’s coming in and what’s currently playing, on separate ears.

The toast confirms Split cue: ON (L=deck A, R=deck B) / Split cue: OFF.

Hot cues

Once a track is loaded, the playing deck has four hot cue slots.

| Key | What it does | |---|---| | 1 / 2 / 3 / 4 | Jump to hot cue 1–4 on the playing deck | | ! / @ / # / $ (Shift+1..4) | Set hot cue 1–4 at the current position |

The dashboard MIXER row shows the state per deck: CUE ●1 ○2 ○3 ●4 — filled dots are set, empty are unset. You can also click the dots on the dashboard (click jumps, Shift-click sets).

BPM, key, and the Camelot wheel

mixr’s auto-transition picker uses two musical-compatibility signals:

• BPM gap percent — how far apart the playing and incoming tempos are. < 8% → mixr beat-matches them. > 8% (or > 14% with the pitch stretcher) → it forces EchoOut, because phase-locking that big a gap will warble.
• Camelot key distance — how many steps apart the two tracks are on the Camelot wheel. 0 (same key) and 1 (adjacent on the wheel) are the most consonant; 2 is a small mood shift; 3+ is enough that mixr picks the safer BeatMatched fade rather than a swap.

Camelot codes live alongside the BPM in every browse track list (e.g. 9A 124). If you tag your local library files with key metadata, mixr reads them; for Beatport tracks the key ships with the catalog metadata.

When you’ve got Claude DJ enabled and want to constrain its track selection by tempo and key, the DJ BPM Gap and DJ Camelot settings (Settings → Claude DJ) take Strict / Prefer / Off — Strict rejects anything off-key or off-tempo, Prefer favors compatible tracks but allows misfits, Off lets Claude pick freely. These settings only affect Claude DJ; the engine’s own auto-transition picker always uses the BPM gap and Camelot distance unconditionally.

Train-wreck handling

A “train wreck” is when two decks are playing audibly out of phase — the beats are flammed instead of stacked. mixr can detect this during a crossfade and either warn you or auto-recover.

Settings → Train Wreck has three modes:

• Off — mixr doesn’t watch for it.
• Detect — mixr watches and pops a toast when it sees one, so you can decide what to do.
• Auto Bail (default) — mixr watches and, on detection, automatically switches the in-progress transition to EchoOut. EchoOut is a hard cut, so the train wreck stops sounding like a train wreck.

Auto-bail fires at most once per crossfade.

You can also bail manually any time with B (capital B) on the dashboard during a crossfade. The toast confirms ⚠ Bailed to EchoOut. If you press B when not crossfading, you get a Nothing to bail (not crossfading) toast.

Quantize, glide, and jump

These three settings shape how musical your mid-mix actions are.

Quantize (Settings → Quantize, on/off) tells mixr to align mid-mix actions — jumps, loop activates, hot-cue sets — to the next beat boundary, instead of firing the instant you press the key. Beats granularity is set by Settings → Quantize Beats: 1/8, 1/4, 1/2, 1, 2, 4, or 8. 1 aligns to the next beat; 4 aligns to the next bar; 8 aligns to the next two-bar boundary.

Glide Bars (8 / 16 / 32 / 64 / Max) controls how long mixr takes to ease the incoming deck’s rate back to 1.0× after a crossfade finishes. Longer = smoother return to the track’s original tempo; Max glides until the next mix.

Jump Bars (4 / 8 / 16 / 32) is the bar count used by the < / > keys when you jump on the playing deck. The dashboard’s ◀ JUMP N ▶ widget shows the current setting and clicking its center cycles through the values.

Master out, monitor device, headphone bus

mixr’s audio routing has two cpal output streams.

Master out — the main mix that goes to your speakers (or to your venue PA via your interface). Pick the device in Settings → Output Device. Apply the Master Limiter (Off / Soft Knee) to round off peaks without hard-clipping; soft knee is transparent at normal levels and folds peaks smoothly to ± 1.0.

Monitor device — an optional second output for your headphones. Pick it in Settings → Monitor Device (or omit, and previews / cue share the master out). The monitor stream takes effect on the next launch.

What flows to the monitor bus:

• The currently-previewed track (when you press Space on a track row).
• With Split Cue on (S), the playing deck on the left channel and the incoming deck on the right channel — so you can pre-listen the mix in your headphones while the main mix plays through the PA.

A note on audio quality: when you’re signed in via dj.beatport.com (mixr’s default), the OAuth scope tops out at 256 kbps HLS (AAC). FLAC requires a higher-tier Beatport scope. Set the quality you want under Settings → Audio Quality.

---

That’s everything you need to mix on mixr. The rest of the manual covers specific topics in depth — Claude DJ, MIDI controllers, the IPC scripting surface — but if you just want to play music, you’ve now got it.