Room Acoustic Test — MATT Modes
Test room acoustics with MATT articulation bursts to find modes, flutter echo and ringing. Your ears beat guesswork here. Free in your browser, no download.
Protect your hearing. Start at a low volume. Never raise the volume to make a tone audible. Levels are shown in dBFS, relative to full scale — not SPL.
How it works
Educational articulation test sequences synthesized in Web Audio API. Emits Hann-windowed tone bursts with precise silent gaps to audibly reveal modal ringing, RT60 decay time-smearing, and room resonance.
Room acoustics have a greater impact on sound quality than speakers, DACs, or amplifiers. Even top-tier studio monitors sound muddy and boomy in an untreated rectangular room.
The Science of Articulation
Music is made of transients—rapid attacks followed by brief rests (e.g., bass guitar notes, kick drum hits). In an acoustically controlled environment:
- Transient Attack: The speaker driver pushes air.
- Instant Decay: The driver stops, and room absorption dampens the reflected wave immediately.
- Articulation: Your ear perceives every individual note clearly separated in time.
Room Resonance & “Mud”
In an untreated room, sound waves reflect back and forth between parallel boundaries. At frequencies that match the room dimensions (room modes):
- Peaks (Anti-Nodes): Standing waves double the volume, creating boomy, muddy bass notes.
- Nulls (Nodes): Sound waves cancel out completely, making certain bass notes disappear.
- Ringing (Time Smearing): Sound takes 300–800 ms to die down. When a new musical note plays, the previous note is still echoing in the room.
The MATT test gives you an intuitive, audible demonstration of this phenomenon across the low-frequency spectrum.
Frequently asked questions
What is a MATT test?
MATT stands for Music Articulation Test Tones, pioneered by Art Noxon (Acoustic Sciences Corporation). It uses rapid sequences of short tone bursts separated by silent gaps (typically 8 bursts per second). If a room suffers from acoustic resonance or long decay times at a particular frequency, the room reverberation fills in the silent gaps, blurring the pulses together into a continuous drone.
Is this an automated measurement tool or a listening test?
This is an educational critical-listening tool rather than a calibrated microphone measurement. By playing articulation sequences through your speakers while sitting in your listening position, your own ears immediately perceive whether bass and low-mid frequencies remain articulate or decay into ringing resonance.
What does it mean if the tone sounds continuous instead of pulsing?
When tone bursts sound blurred or continuous, you have hit a room mode (standing wave) at that exact frequency. The acoustic energy is trapped between your room boundaries (walls, floor, ceiling) and continues to ring out after the speaker driver has stopped moving.
How do I fix room mode ringing discovered with this test?
Modal bass ringing is resolved through acoustic treatment—specifically corner bass traps (porous absorption or membrane/diaphragmatic traps) which absorb low-frequency energy where pressure builds up in room corners, and proper subwoofer/speaker placement.