How It Works

The Stadium PA effect is a layered signal chain implemented with the Web Audio API to emulate reflective decay, spectral shaping, and PA system coloration.

Why A Dedicated Stadium PA Filter?

Generic reverb presets rarely reproduce the compound texture of real stadium paging systems. A ballpark PA mixes architectural reflections, horn-loaded speaker roll-off, and moderate nonlinear saturation. This tool encodes those nuances as curated presets so you start from a convincing baseline and then refine.

Under the hood we chain calibrated delay clustering, multi-band shaping, and dynamic-range compression — plus, for the Megaphone preset specifically, a resonant harmonic boost that concentrates energy right where its clip stage bites hardest.

Signal Chain Overview

1. Pre-Delay: Simulates initial propagation delay before reflections build.
2. Reverb / Late Reflections: A tapped delay-and-decay echo series plus a short decaying noise tail approximate large enclosure reflections.
3. EQ (High / Low Cut): Bands limiting extended lows & highs typical of horn-loaded arrays.
4. Distortion / Saturation: Mild non-linear stage coloring transients.
5. Compression: Controls dynamic range for consistent intelligibility.
6. Wet/Dry Mix: Blends original articulation with spatial coloration.

Tips for Best Results

Start with a clean, mono voice recording at a moderate level, with peaks around -6 dBFS — that leaves headroom for the compression and saturation stages, which both add level before the final normalisation pass. Keep the source dry. The preset is already adding a room; stacking your own reverb on top of it smears consonants and costs intelligibility.

• Pre-Delay: increase it for larger perceived venues — it is the gap before the first reflection arrives, so a longer gap reads as a bigger room.
• High Cut: lower it for a vintage horn timbre; raise it toward 6 kHz for modern line-array clarity.
• Distortion: keep it between 10% and 25% for realism. Past that it stops sounding like a driven speaker and starts sounding like a damaged file.
• Echo Delay: the secondary reflections are spaced from the pre-delay, so widening it pushes the repeats further apart and makes the space feel deeper rather than merely louder.

Choosing a preset

Ballpark is the open-air default: a short 1.3-second tail and a wide 200 Hz–5.5 kHz band, so the words stay readable. Arena doubles the tail to 2.2 seconds, blends in far more of the wet signal and rolls the top off near 4.1 kHz — that boxy, indoor, everything-is-loud sound. Vintage and Classic narrow the band further (4 kHz and 3.5 kHz respectively) and add more saturation for older horn clusters, while Modern goes the other way with the widest passband and the lightest compression. Outdoor is the largest space on the list — the longest tail and pre-delay and the most wet signal, which the ear reads as distance. Megaphone is not a room at all: it squeezes everything into a narrow honk band around 1–2.4 kHz and clips it hard.

Processing Constraints

All steps execute in real time; large files may consume more memory. Browser sample-rate or autoplay restrictions may affect playback.