Smash Happy Audio — User Manual

Meridian

A precision metering suite — VU, full BS.1770-5 loudness, true peak, and a Real World Matrix that lets you audition how a master will actually translate.

Formats · AU, VST3 (macOS) Version · 1.0 Manufacturer · Smash Happy Audio
01 / Overview

What Meridian is for

Meridian is a pass-through analyser — it reads your audio, measures it in several genuinely useful ways at once, and passes it through unmodified except when you deliberately engage a Real World Matrix monitoring filter to audition a translation scenario. Nothing it does changes your master unless you ask it to.

Four instruments live side by side: a calibrated VU meter, a full BS.1770-5 loudness suite (momentary, short-term, integrated, and loudness range), a 4x-oversampled true-peak meter, and the Real World Matrix — three toggleable filters that simulate how your master will sound on a phone speaker, after streaming-platform loudness normalization, or over Bluetooth.

02 / The Interface

The interface

Four columns run left to right: VU Meter, LUFS Display, True Peak, and Real World Matrix, all reading the same signal simultaneously — you never have to switch modes to see level, loudness, and inter-sample peak behaviour together.

03 / VU Meter

VU meter

A calibrated segmented VU meter with proper 300 ms ballistics. Calibration is adjustable from −18 to −6 dBFS (default −18) so 0 VU can be set to match whatever reference level you're working against.

04 / LUFS

LUFS

Full BS.1770-5 loudness metering with proper K-weighting: Momentary (400 ms), Short-Term (3 s sliding), and Integrated (the two-stage absolute + relative gated measurement the spec actually requires — not a simplified approximation), plus Loudness Range. Use START / STOP / RESET to control an integrated measurement pass over a full track.

Accuracy

Meridian's LUFS engine has been verified against an independent BS.1770 reference implementation on real mastered material, matching within hundredths of a LU — this is a genuine spec-accurate measurement, not a loudness estimate.

05 / True Peak

True peak

4x-oversampled true-peak metering catches inter-sample peaks that a plain sample-peak meter misses entirely — the kind of over that only appears after your master is converted to a lossy format. CLIP lights and latches when 0 dBTP is exceeded; RST clears it. An overall peak-hold tracks the loudest true-peak moment across the session.

06 / Real World Matrix

Real World Matrix

Three toggles let you monitor through a simulated real-world listening scenario without leaving your DAW:

Smartphone TrapSums to mono, band-limits ~350 Hz–6 kHz — what a phone speaker actually reproduces
Streaming PenaltyApplies the gain offset a streaming platform's loudness normalization would impose against your Stream Target
Bluetooth TranscodeA high-frequency shelf cut approximating lossy Bluetooth codec transcoding

Toggle any of them on to hear — and see, via the dedicated meters each one drives — exactly how your master degrades in that scenario, then adjust with that translation in mind rather than guessing.

07 / Specifications

Specifications

FormatsAudio Unit, VST3
PlatformmacOS 12+, universal binary (Apple Silicon + Intel)
Loudness standardITU-R BS.1770-5, momentary/short-term/integrated + LRA
True peak4x oversampled, dBTP with latched clip + peak hold
VU calibration−18 to −6 dBFS for 0 VU
Real World MatrixSmartphone Trap, Streaming Penalty, Bluetooth Transcode
ProcessingPass-through — signal is unmodified unless a Matrix filter is engaged
Channel configurationMono or stereo in / stereo out
08 / Troubleshooting

Troubleshooting

My integrated LUFS reading doesn't match another meter exactly

Small differences (a few hundredths of a LU) between spec-accurate BS.1770 implementations are normal and usually trace to filter normalization or gating edge cases — Meridian's engine has been independently verified against a reference implementation. Larger gaps usually mean the other meter isn't fully spec-compliant, or you're comparing Integrated against Short-Term/Momentary by mistake.

True Peak shows a clip my sample-peak meter didn't catch

That's expected and the whole point of true-peak metering — inter-sample peaks exceed 0 dBTP without any single sample in the file itself clipping. Back off your ceiling if this happens regularly.

A Real World Matrix toggle doesn't seem to change anything

Confirm you're actually listening through Meridian's output (not monitoring pre-fader) and that the toggle is actually engaged — each one is a real, audible filter change, not a meter-only simulation.