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RJ-Limiter · Manual

RJ-Limiter: Manual

Version 1.0Updated 2026-07-06

RJ-Limiter is the limiter I always wanted at the end of a master chain. It holds the ceiling reliably, it measures honestly in dBTP, and it doesn't hide its clipper inside some style menu but puts it right on the surface as its own knob. I deliberately did not chase zero latency. A mastering limiter naturally has latency, and the goal isn't being latency-free, it's the best possible limiting. What you see in the centre is exactly what comes out: an output envelope that visibly hangs at the ceiling and stays there.

Overview

RJ-Limiter is a transparent true-peak brickwall in the class of a FabFilter Pro-L 2. Under the hood it works in two stages. First a musical, downward-only release stage with your Attack and Release ballistics, crest-adaptive. Then an oversampled pre-clipper, then a fast brickwall with a fixed analysis window, and finally a baseband true-peak clamp that closes the dBTP guarantee. Only the fast stage and the clamp actually touch the ceiling. The musical stage pre-forms the signal but never measures against the ceiling.

Version 1 is deliberately broadband. M/S and multiband come in v2. The ceiling is also the output level, there is no separate output knob. And the clipper has no colour engine built in, that stays in RJ-Saturation. Here it is a pure, unity-gain pre-shaver.

The Interface

At its heart is the LimiterScopeView in the centre, a scrolling dB-domain animation in the Pro-L-2 style. The vertical axis is linear in dB and runs from +6 dB at the top to −36 dB at the bottom, and time scrolls right to left. There is a faint grid line every 6 dB, with the 0 dBFS line emphasised.

  • A dashed ceiling line (burgundy) with an inline label sits at the ceiling value.
  • A dashed clip line (amber) sits at the threshold T = ceiling + (4 − Clip). As you turn CLIP up, this line slides down toward the ceiling.
  • With clip engaged, the working zones tint: amber above the clip line (the clipper's territory), burgundy between the clip line and the ceiling (what the limiter smooths).
  • Behind the darker delivered output envelope sits a light input ghost envelope. The input overshoots above the ceiling while the output visibly flattens against it and hangs at the line. That is the whole point of a limiter.
  • A two-colour gain-reduction overlay hangs down from the top edge: amber on top for the clip depth, burgundy below it for the limiter GR. A dashed PEAK marker shows the deepest total reduction in view.
  • Top right sits one large GAIN REDUCTION read-out. All GR displays show the total reduction from limiter and clip. Only the read-out at the CLIP knob shows the clip share separately.

On the right sits a collapsible metering column with four scaled vertical bars and a live value under each: IN and OUT as stereo sample-peak bars, GR, and a LUFS ladder with target ticks for Spotify (−14) and Apple (−16) plus an integrated marker. The OUT read-out is the held maximum true peak (dBTP), exactly the quantity external analyzers measure against. It goes red over the ceiling.

Controls & Parameters

Eight knobs in the footer, left to right: INPUT, CEILING, ATTACK, RELEASE, LOOK, BASS, CLIP, LINK. Double-click any knob to reset it to default, that is the suite-wide gesture.

Level & Ceiling

  • INPUT: −24 … +24 dB (default 0). The drive into the limiter. Loudness is INPUT's job, the clipper has no make-up. Ramped, click-free.
  • CEILING: −24 … 0 dB (default −1.0). This is the output level, there is no output knob. The guarantee holds the true peak at or under this value.

Ballistics of the musical stage

  • ATTACK: 0 … 2000 ms (default 250). The ballistics of the musical stage, never latency. Long means transients run untouched into CLIP and the fast stage, and the GR recovers immediately after. That sounds punchy, almost like a clipper. Short means the stage grabs everything smoothly.
  • RELEASE: 5 … 3000 ms (default 500). The recovery of the musical stage. Crest-adaptive inside, percussive faster, tonal slower. Fully linked, which protects the stereo image.

Fast stage

  • LOOK: 0.1 … 5 ms (default 1.5). The analysis window of the fast brickwall, in a fixed-max-report pattern. The reported latency stays pinned at the 5 ms maximum, so this knob is never structural and is click-free. Window changes crossfade two fully warmed gain chains. Short is punchy and dirtier, long is softer and more transparent because it ducks earlier. Measured THD at 997 Hz: LOOK 0.1 = −55 dB, LOOK 5 = −94 dB.
  • LINK: 0 … 100 % (default 80). The stereo link of the fast stage. The musical stage stays fully linked, and lows under about 120 Hz are always fully linked. Unlinking therefore only frees HF transients, that is "free loudness", while the bass image can't move.

Low end

  • BASS: 0 … 100 % (default 0, off and bit-neutral). LF-aware release. A tracker around 150 Hz floors the effective release of both stages to at least a fraction of one bass period, so the gain can't ride inside a bass waveform cycle. That is the number one mechanism for LF distortion. Higher means cleaner, sustained bass at a slightly slower LF recovery.

Clipper

  • CLIP: 0 … 4 dB (default 0). The ONE clip knob. It sets how many dB of the final peak control the clipper takes over from the limiter. The threshold is T = ceiling + (4 − Clip). 0 = off (bit-exact), 4 = clip right at the ceiling (pure clipper, the limiter idles). Unity-gain below the knee, no hidden make-up. Memoryless, 0 latency. With a long ATTACK the transients the musical stage passes hit this clip first. That is the limiter versus clipper interplay. The small chevron opens the CLIP overlay.

The CLIP overlay (called from the chevron at the CLIP knob):

  • BYPASS: bypass the clipper entirely, the amount value is kept. Memoryless, so not structural.
  • MIX: 0 … 100 % (default 100). The clipper's dry/wet. 100 = plain clipper, less = parallel clipping.
  • SHAPE: 0 … 100 % (default 0). Soft-knee (0, reads SOFT) to hard (100, reads HARD).
  • TRANSIENT: 0 … 100 % (default 0). Onset routing. Onsets are briefly clipped at the ceiling instead of ducking the limiter envelopes. Punch without pump, and it works even at Clip 0.

Next to the CLIP title sits a tiny live read-out for the current clip reduction while the clipper is actually engaged.

Header, Oversampling & the guarantee

The header holds, left to right, the PRESET dropdown (save and load as .rjlimiter with a product marker so sibling-plugin presets can't load), OVERSAMPLING (Off / 2× / 4× / 8×), QUALITY (Low-Latency / High-Quality), TRUE PEAK (on/off) and BYPASS.

Oversampling is factor times quality:

  • OS factor: Off / 2× / 4× / 8× (default 4×). The full dBTP guarantee needs at least 2×. "Off" is physically detection only, the host-rate detector can't fully resolve inter-sample peaks near Nyquist, and it is honestly greyed in the UI. 8× forces the linear-phase engine.
  • QUALITY: Low-Latency (minimum-phase IIR, least latency) or High-Quality (linear-phase FIR, flat phase, more latency and CPU).

Only the two OS switches are structural, they re-report PDC latency. Attack, Release, Look, Link and Clip never change latency and are click-free. The baseband clamp uses one uniform reserve of 0.05 dB across all regimes, so an identical clip setting delivers the same loudness in every OS mode. Even under deep drive up to +24 dB in, the worst true peak stays about 0.005 dB under the ceiling.

Mastering tools

The footer carries a toggle row of tools around the guarantee chain, all neutral at default:

  • DELTA: hear only what was removed (dry_delayed − wet), delayed by the exact current PDC latency so a transparent signal cancels to silence. IN/OUT/LUFS/dBTP keep showing the delivered programme.
  • A/B MATCH: gain-matched equal-loudness bypass. In bypass the dry is lifted to the wet's loudness so A/B compares character, not level. It only affects the bypass path.
  • DC: an opt-in 2nd-order high-pass around 5 Hz on the input to remove a static offset before it eats headroom. Default off, bit-exact.
  • DITHER: Off / 16-bit / 24-bit. Terminal TPDF plus 2nd-order noise shaping, applied only on bit reduction. The ceiling is pre-lowered by the dither's worst-case peak so the guarantee still holds. Never applied in bypass or delta.

Practical Tips

  • Loudness comes from INPUT, not the clipper. The clipper is unity-gain below the knee. Push INPUT to taste and keep CEILING around −1.0 dBTP for streaming safety.
  • Punch close to a clipper, but with body: long ATTACK plus some CLIP. The limiter lets transients through, the clipper catches them, and the smooth body stays intact.
  • LOOK as a character control: short for more clipper character and punch, long for softer and more transparent. Because latency is fixed you can automate and compare freely.
  • On bass-heavy material, turn BASS up so the low end doesn't pump or ride. It costs some LF recovery speed.
  • Leave the lows linked: LINK around 80 % frees HF transients for extra loudness while the bass image stays put.
  • Use OS at least 2× for the full guarantee. OS Off is an honestly labelled low-latency detection-only mode. Watch the OUT dBTP read-out, it matches external analyzers.

Installation & Activation

RJ-Limiter runs as VST3, AU and AAX on macOS and Windows.

  1. Download and run the installer, then reopen your DAW.
  2. On first launch you get the 30-day, fully functional trial, no limitations.
  3. After purchase, enter your license key in the plugin's info area. Done. The key works for Mac and Windows alike.

Questions about activation or workflow? Just write to me directly. I build these tools myself and I'm glad to help.