How to Master in REAPER (Stock JS/ReaPlugs)

Updated August 2026 · by Loopin

You can master entirely with REAPER’s stock ReaPlugs on the master track: ReaEQ for corrective EQ, ReaXComp for multiband compression, an optional JS saturator for character, then ReaLimit as a true-peak limiter with a −1 dB ceiling. REAPER’s built-in JS loudness metering and the loudness readout in Render let you land near −14 LUFS before you bounce to WAV. Prefer to skip the chain-building? Loopin’s browser mastering does it automatically.

Why REAPER is great for mastering

REAPER ships with a full set of stock plugins — the ReaPlugs suite plus a huge JS (JesuSonic) scripting library — so you can build a complete master chain without buying a single third-party plugin. It’s CPU-light and endlessly configurable.

Just as important, REAPER includes proper loudness metering. There’s a JS LUFS meter for real-time monitoring, and the Render dialog can measure loudness on the way out — so you can hit a streaming target with confidence instead of guessing.

Stock ReaPlugs cover the whole chain — EQ, comp, limiting
JS scripts add saturation and metering for free
Built-in LUFS metering for real-time monitoring
Render measures loudness so you can confirm your target

Open the Master track’s FX window (the FX button on the master) — all mastering goes here, not on individual channels.
Add a JS loudness/LUFS meter so you can monitor integrated loudness live.
Confirm your mix bounce feeds the master with headroom — no clipping on the way in.
Build the chain in order: ReaEQ ’ ReaXComp ’ saturation ’ ReaLimit.

Step 1 — ReaEQ (corrective)

Insert ReaEQ first for corrective moves. This is about cleaning up the mix, not reinventing it — a high-pass to trim useless sub, and gentle wide cuts where the balance is boxy or harsh.

Keep boosts small. Broad, subtle changes translate far better on a master than narrow surgical ones.

High-pass the rumble below the useful low end
Cut mud or harshness with wide, gentle bands
Small boosts only — a touch of air can help
Aim for a cleaner version of the mix, not a new tone

Step 2 — ReaXComp (multiband compression)

Next add ReaXComp for multiband compression. Splitting the spectrum into bands lets you control the low end independently from the mids and highs, so bass movement doesn’t duck the whole track. ReaXComp gives you as many bands as you need, and each has its own threshold, ratio and gain, so you can treat problem areas surgically while leaving the rest of the mix alone.

At the master stage go gently — a small amount of gain reduction per band for glue and control, not obvious squashing. Solo each band briefly to hear what it’s catching, then set the crossover points where the instruments naturally divide so the compression stays transparent.

Independent bands keep bass from pumping the whole mix
Gentle reduction per band — glue, not crush
Tame any band that jumps out (often the low mids)
Listen for cohesion, not audible pumping

Step 3 — Saturation (optional JS character)

For a bit of character, insert a JS saturator after the multiband stage. A hint of saturation adds harmonics and perceived warmth or loudness without heavy limiting.

This step is optional and should stay subtle — drive it until it flatters the track, then back off before it sounds obviously distorted.

Adds harmonics and perceived warmth
Keep it subtle — flavour, not distortion
Sits after multiband, before the limiter
Skip it if the track already sounds full

Step 4 — ReaLimit at a −1 dB ceiling

End the chain with ReaLimit, REAPER’s true-peak limiter. Set the ceiling to −1 dB so nothing exceeds that level on output — the headroom protects against clipping when a platform re-encodes to a lossy format.

Use ReaLimit as the brickwall safety net. Push into it only as much as needed to reach your loudness target; heavy limiting here means something earlier in the chain is too hot.

Set the ceiling to −1 dB (true peak)
It’s the last plugin in the chain
Use it to brickwall peaks, not to force loudness
Watch gain reduction — a little goes a long way

Hitting about −14 LUFS and rendering

With the chain in place, use REAPER’s loudness meter to aim for about −14 LUFS integrated across the whole song — the level the major streaming platforms normalize toward. Adjust ReaXComp and the limiter input a touch until the integrated reading settles there.

Then render with the limiter still in the chain so your final file matches what you heard:

Play the full track and read integrated LUFS on the meter — nudge levels toward about −14 LUFS.
Open File ’ Render and set format to WAV.
Enable the loudness measurement in the Render dialog to confirm the integrated value.
Render Master mix with the ReaLimit brickwall in place — don’t bypass it.
Check the reported LUFS and true peak, then you’re done.
Want it done for you? Drop the raw mix into Loopin’s free mastering tool and it targets −14 LUFS and −1 dBTP automatically.

Common mistakes in REAPER mastering

Processing tracks instead of the master — the master chain belongs on the master track.
Rendering without measuring loudness — enable the Render loudness readout so you confirm about −14 LUFS.
Bypassing ReaLimit on render — render with the brickwall in place or your file won’t match what you heard.
Over-driving ReaXComp — multiband is for glue and control, not squashing.
Setting the limiter above −1 dB — the −1 dB ceiling leaves headroom for lossy encoding.
Chasing loudness past −14 LUFS — streaming turns hot masters down and keeps the artifacts.

The faster free alternative

Stock ReaPlugs give you total control, but wiring ReaEQ, ReaXComp, saturation and ReaLimit and dialing each one takes time and a good ear. Loopin’s online mastering runs the same sequence — corrective EQ, multiband compression with an independent low end, saturation, M/S stereo shaping, two-pass loudness targeting to about −14 LUFS and a true-peak limiter at −1 dBTP — automatically in your browser.

It’s free, needs no signup, uploads nothing, and adds no watermark. A/B it against your mix and export a 16-bit WAV in minutes, then take it back into REAPER if you want to fine-tune.

Frequently asked questions

Can you master in REAPER with only stock plugins?

Yes. REAPER’s stock ReaPlugs cover a full master chain on the master track: ReaEQ for corrective EQ, ReaXComp for multiband compression, an optional JS saturator, then ReaLimit as a true-peak limiter with a −1 dB ceiling. Render to WAV with the limiter in place.

What LUFS should I target when mastering in REAPER?

About −14 LUFS integrated, which matches the level major streaming platforms normalize toward. REAPER’s JS loudness meter and the Render loudness measurement let you confirm you’ve landed there before bouncing.

Does REAPER have a loudness meter?

Yes. REAPER includes JS loudness/LUFS metering for real-time monitoring, and the Render dialog can measure loudness on the way out, so you can confirm your integrated LUFS and true peak.

What ceiling should ReaLimit use?

Set ReaLimit’s ceiling to −1 dB. As a true-peak limiter it brickwalls peaks below that level, leaving headroom so lossy encoders don’t clip on playback. Render with it in place.

Is there a faster free alternative to building a REAPER chain?

Yes. Loopin’s browser mastering runs corrective EQ, multiband compression, saturation, stereo shaping, loudness to about −14 LUFS and a −1 dBTP limiter automatically. It’s free, uploads nothing, and exports a 16-bit WAV.