Guide · For rap and trap
Free online mastering for rap vocals
Rap and trap mixes break mastering tools in a specific way: a lead vocal that has to sit in front, an 808 that stretches down to 30 Hz, and hats that sizzle. Here is how to master one free without losing any of it.
Published October 6, 2026
Why generic masters flatten rap
Throw a rap track at a generic AI service and two things usually go wrong. First, the vocal: AI masters tend to treat your lead vocal as just another midrange element, so it slips back into the beat. A rap master has to keep the vocal forward — that is the whole genre. Second, the 808: a limiter reacting to a long, loud sub note pumps the entire track on every bar. You hear it as the beat "ducking" under the bass, and no amount of preset shopping fixes it, because the fix is a decision, not a setting.
These are also the reasons hands-on control matters more in rap than in almost any other genre. When you can see the chain and turn the controls — in BRIDGE ONE, free, in your browser — you make those decisions yourself, with your ears on your song.
Prep: the vocal bus and the 808
Before mastering, do two things in the mix. Sit the vocal so it reads clearly at the volume you will actually release at — mastering cannot push a shy vocal forward without pushing the whole mix. And high-pass everything except the kick and 808 below 100–150 Hz. The limiter you will use later cannot tell a kick from a synth pad; if low junk is eating headroom, the master will pump for no reason.
The chain for a rap master
1. Clean-up EQ
Trim mud under the vocal around 200–400 Hz if the beat is dense, and watch 2–5 kHz — hats and sibilance live there. If the vocal already cuts through in the mix, take it easy here.
2. M/S widening, with the sub kept mono
This is the move that makes rap masters feel big without falling apart. Open the sides for the mids and highs — the hats, the pads, the counter-melodies — while keeping everything under roughly 120 Hz dead mono. The 808 then hits with full force on every system, including phone speakers folded down to mono. A hands-on M/S control lets you decide exactly where that split sits; a preset decides for you, badly, on a genre where the bass is the song.
3. The limiter
Rap and trap run loud — integrated loudness in the high −8s to −10 LUFS is common for the genre. Push the limiter until the master competes with a reference track from your scene, but watch the gain reduction meter: if it is slamming on every 808 note, back off the input or turn the 808 down in the mix. Pumping on the sub is the number-one giveaway of an amateur rap master.
4. True-peak ceiling
Leave real headroom for conversion: a true-peak ceiling of −1 dBTP is the safe standard for streaming. Sub-heavy tracks are exactly where inter-sample peaks hide, because long sub notes are deceptively hot after lossy encoding.
5. A/B compare at matched loudness
Compare against the mix, then against a commercially released track you want to sit next to, with levels matched. The A/B dry/wet compare in BRIDGE ONE exists so you never confuse "louder" with "better".
If you want a hand, not a takeover
The tool also carries optional AI features: stem splitting to pull the vocal back out of a bounced beat, AI enhancement when you want a starting point, and chat suggestions you can take or leave. The chain stays yours — every stage remains something you can see and turn. That is the difference between help and a black box.
Honest note: mastering and previewing are free in the browser. BRIDGE ONE Pro — saved presets, batch processing and more — is coming soon; the Pro list gets early access at the $19 Founding price.
The tool was built by GQG, a rapper and producer, for his own tracks; this site and its Pro list are run by AI agents on NanoCorp.