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👋
Before we start — what should REX call you?
GETTING THE BEST FROM REX
01 — GIVE REX A BRIEF
REX is an engineer, not a button. The more direction you give him before hitting MIX, the better the result. Tell him:
Genre & vibe— "Trap, dark and heavy" or "Lo-fi hip-hop, warm and intimate"
Reference— "Like a Travis Scott record" or drop a reference track using the REF button
Destination— "Going on Spotify" or "for the club" tells REX exactly how loud and wide to push it
Problem— "The vocals feel buried" or "the low end is too muddy" gives REX something to fix
02 — WHAT TO SAY
These are real things you can type to REX:
"Trap beat, going on Spotify. Make the 808 knock and keep the hi-hats crispy."
"R&B, warm and smooth. The vocals need more presence without sounding harsh."
"Match the energy of the reference track I uploaded. It should feel that wide and that loud."
"The kick isn't hitting hard enough and the bass is fighting it. Fix the low end."
"House music. Big room energy, going on Tidal. Wide and punchy."
03 — REVISE, DON'T START OVER
After REX delivers a mix, play it back and tell him exactly what's wrong. He remembers what he did and makes surgical adjustments — he doesn't rebuild from scratch.
"The vocals are still a bit buried. Push them forward and add a bit more air."
"The low end is perfect but the top feels harsh. Just fix that."
"Make it a bit wider and bring the reverb down slightly."
04 — POWER TIPS
🎯Use a reference track. Drop a professional mix you love into the REF slot. REX will analyse its loudness, frequency balance, and width — then aim for the same.
📻Name the platform. Spotify, Apple Music, YouTube, and the club all have different loudness standards. REX knows them all and will hit the right target automatically.
🎚️Label your stems correctly. In stems mode, REX uses the stem type (kick, bass, lead vocal, etc.) to make mix decisions. A correctly labelled session gives REX everything it needs.
💬Talk to REX before you mix. Chat with him first — describe the feeling you want, ask what he's hearing in the analysis. The brief you build in conversation becomes the mix.
Meet REX, your mixing engineer.
REX is a mixing and mastering engineer who lives in your browser. Drop your audio, tell him what you're going for, and he handles the whole mix: EQ, compression, dynamics, reverb, stereo image, and loudness — all calibrated to your genre.
No DAW. No plugins. No install. Just audio in, professional mix out.
🎚️
What are stems?
Stems are the individual tracks of a song — each instrument or group exported as its own file from your DAW. REX gets a much better mix when he can work with each element separately.
Drums
Bass
Vocals
Keys
Pads
Don't have stems? Use Single Track mode — drop in your full mix and REX will work with that. Or hit ✂ SPLIT INTO STEMS and REX will separate your track automatically before mixing. For best results, use the cleanest, least processed version of your audio — the source quality directly affects how clean the stems come out.
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How it works
1
Drop your stems (or a single track) and pick your genre
2
Tell REX what you're going for in the Mix Brief or just chat with him
3
REX analyzes the audio and applies a full professional mix — EQ, compression, dynamics, width, reverb
4
Preview, tweak with faders, or send REX back in with revision notes — then download
🔑
You'll need an API key
You're in. As a FADE PUSH beta tester, REX is fully activated and ready — no setup required. Just drop your audio and let him work.
Beta access is completely free — no credit card, no account needed
Drop your track, tell REX how you want it to sound, and he handles the rest
Your feedback shapes the final product — we want to hear everything
Your key is stored locally in your browser only and never shared with anyone.
🎶
Ready to mix?
REX is standing by. Drop your stems, pick your genre, give him a brief — and let him work.
Hit ? in the top bar any time to revisit this guide.
REX'S MIX
—
WAVEFORM · CLICK OR DRAG TO SCRUB
0:00 / 0:00
EQ CURVE
SETTINGS APPLIED
COMPARE: REX'S MIX vs REFERENCE
REX'S MIX
—
0:00 / 0:00
EQ CURVE APPLIED BY REX
REFERENCE TRACK
—
0:00 / 0:00
ORIGINAL · UNPROCESSED
Reference track REX calibrated your mix to match.
REFERENCE TRACK FREQUENCY PROFILE
✂ SELECT SPLIT TYPE
2 STEMSVocals · Instrumental
Fastest and cheapest. Best for quick remixing or vocal work.
4 STEMSVocals · Drums · Bass · Other
Standard split. Good balance of detail and processing time.
6 STEMSVocals · Drums · Bass · Guitar · Piano · Other
Most detailed. Recommended for full production mixing.
◉
DROP YOUR TRACK
MP3 · WAV · FLAC · AAC
INPUT LEVELS
PEAK L
—
PEAK R
—
RMS
—
SESSION HISTORY
0
No saved sessions yet. After a mix, click Save Session to store it here.
HOW ARE WE MIXING TODAY?
🎵 SINGLE TRACK
Got a full song or rough bounce? REX enhances the whole track — EQ, compression, stereo width, loudness target. Ready in seconds.
🎚️ STEMS SESSION
Drop your individual tracks — kick, bass, vocals, keys, pads. REX builds the full mix from scratch, stem by stem.
01DROP YOUR AUDIO — any format. No DAW required, no install, no plugins.
02PICK YOUR GENRE — REX knows what every genre should sound like at a professional level.
03BRIEF REX — describe the sound you want in plain English. He reads it, he delivers it.
04DOWNLOAD YOUR MIX — WAV or MP3, mixed and mastered, ready for distribution.
TRACK ANALYSIS
PEAK
—
dBFS
RMS
—
dBFS
DYN RANGE
—
dB
CREST
—
dB
STEREO
—
SAMPLE RATE
—
kHz
FREQUENCY BALANCE
GENRE
REFERENCE TRACK
OPTIONAL
◈
DROP A REFERENCE TRACK
REX will calibrate your mix to match this song
REFERENCE
STEM LABELS — VERIFY & CORRECT
GENRE
REFERENCE TRACK
OPTIONAL
◈
DROP A REFERENCE TRACK
REX will calibrate your mix to match this song
REFERENCE
REX IS WORKING
Sending to REX...
SPLITTING STEMS
Uploading to stem splitter...
REX will load and analyse each stem when ready
REX'S MIX
Click to preview & scrub
EQ CURVE APPLIED
SETTINGS APPLIED
PER-STEM MIX
REVISE MIX · SEND REX BACK IN
ADJUST MIX · TWEAK WITHOUT RE-MIXING
BASS0
BRIGHTNESS0
REVERB0
WIDTH0
LOUDNESS0
COMPRESSION0
REVERB and COMPRESSION add on top of REX's mix. BASS, BRIGHTNESS, WIDTH and LOUDNESS adjust in both directions.
EXPORT MIX
EXPORT STEMS
INDIVIDUAL STEMS
REX
· MIXING ENGINEER
Ready — load a track or stems to begin
Select a mode and drop your audio. REX handles everything from there.
REX // MIXING ENGINEER
What's good. Drop whatever you've got — a full track, rough mix, or a whole session of stems. While you're doing that, talk to me: what's the vibe, what genre are we in, who are you trying to sound like? The more you give me upfront, the sharper the mix. No forms, no technical jargon — just tell me about the track and what you're going for. That's your brief. EQ, compression, dynamics, stereo image, loudness — I've got all of that. You just bring the vision. Let's hear it.