Room Acoustics Test (MATT)
Check how your room treats sound, not just your speakers. The test sweeps a train of short tone bursts — a clean, fast “Ta-Ta-Ta-Ta” — across the low end. Where the room resonates, the bursts smear into a blur. Tap Mark when you hear it and the frequency is logged.
Tap the moment the bursts blur together; the frequency is logged.
Start low and raise the volume to a clearly audible, comfortable level — loud enough to excite the room. Run it once on headphones first to learn the clean reference.
Headphones bypass the room, so one pass on them teaches you the clean “Ta-Ta-Ta-Ta” every burst should have.
Through speakers, listen for bursts that run together, boom, or lose their sharp attack — that is the room talking.
Each mark logs a frequency. Reposition or treat the room, sweep again, and watch the marks disappear.
MATT — Musical Articulation Test Tones — was developed by Acoustic Sciences Corporation in 1986 and is still the classic way to hear a room fail. A frequency-response sweep only tells you how loud each frequency plays, never what happens after the note stops. Music is built from starts and stops, and a resonant room rings on through the stops: bass notes hang over, transients lose their edge, articulate playing turns to mush. MATT makes that audible by gating a slow sine sweep on and off eight times a second, leaving silent gaps between the bursts. Room reflections and resonances fill those gaps, so the frequencies where your room blurs the pattern are the frequencies where it blurs your music.
The signal is generated locally with the Web Audio API: a sine sweep gated into 8 bursts per second at a 50% duty cycle, rising at a constant rate so the readout always shows the frequency being played. Run it on headphones first — they bypass the room, so you learn what a fully articulate pattern sounds like. Then play the same sweep through your speakers from your normal listening position. Wherever the crisp Ta-Ta-Ta collapses into a steady tone, a flutter, or a boomy hangover, press mark; the frequency is logged and the full list appears when the sweep ends. Nothing is recorded or uploaded.
How do I read what I hear?
Three things give a room away. Smearing: bursts that run together instead of separating cleanly, because the room is filling the silent gaps. The disappearing attack: each burst normally starts with a tiny click-like edge, and that edge is the first thing reverberation swallows, well before the bursts audibly merge. Unevenness: bands where the bursts jump out louder or nearly vanish, the signature of standing waves boosting and cancelling. Problems come and go in narrow bands a few tens of hertz wide — clean articulation, then a smeared patch, then clean again. Smeared on speakers but clean on headphones is the room or the speaker placement; blurred on headphones too is the gear.
Common problem bands and what fixes them
| What you hear | Likely cause | What helps |
|---|---|---|
| Boomy, one-note hangover, roughly 30–80 Hz | Axial room modes — standing waves between parallel walls, floor and ceiling | Bass traps in the corners, front two first; sweep again after each change |
| Bursts vanish or double in loudness, roughly 80–200 Hz | Speaker-boundary interference — the reflection off the wall behind the speaker cancels or reinforces the direct sound | Move the speakers off the front wall or shift the seat; even 20–30 cm changes the band |
| Smearing and harshness, roughly 200–500 Hz | Early reflections from the desk, floor, side walls, or a bare ceiling | A rug between speakers and seat, panels at the first reflection points |
| Washed out on speakers, crisp on headphones | A live, reverberant room — bare walls, hard floor, little furnishing | Curtains, bookshelves, soft furnishings; anything absorbent or diffusive |
| Blurred or buzzing bursts on headphones too | The gear itself — a resonant driver, a rattling enclosure, or heavy processing | Turn off EQ and “enhancement” DSP, then recheck the drivers |