Play a sweep through your speakers, record how the room responds with the microphone and get the impulse response: reverberation (RT60) by bands, real bass resonances, a waterfall and EQ suggestions. No REW install, no driver setup.
Measure your room's acoustics online, straight from the browser: the tool plays an exponential sine sweep through your speakers, records the room with your microphone and computes the impulse response — the same ESS technique behind REW, without installing anything or fighting audio drivers. From it you get the RT60 reverberation time by bands (Schroeder integration), the in-room frequency response, the real bass resonances of your room, a waterfall of how they decay and corrective EQ suggestions ready for Equalizer APO or a miniDSP.
Honest scope
With an uncalibrated phone or laptop mic the level curve is relative: its shape is very informative, its absolute values are not. What survives beautifully is what matters for treating a room: RT60 and mode frequencies. If you own a measurement mic (UMIK-1, iMM-6), load its calibration file and the curve gets corrected — locally, nothing is uploaded. Pair it with our room acoustics calculator to cross-check measured peaks against the theoretical modes of your room's dimensions.
Frequently asked questions
How does it measure the room from a browser?
It plays an exponential sine sweep (the same ESS technique used by REW and pro tools), records it with your mic, and deconvolves the capture against the sweep's inverse filter in a background worker. The result is the room's impulse response, from which it derives RT60 (Schroeder integration), the in-room frequency response, modal peaks and a bass waterfall.
What can I trust, exactly?
RT60 and mode FREQUENCIES are robust: they depend on relative decay and peak positions, which survive browser latency and an uncalibrated mic. The frequency response is relative — its shape is informative (peaks, dips, tilts) but absolute levels are not, and phone mics lose output below ~40-50 Hz.
Can I use a measurement microphone?
Yes, and it's the biggest upgrade: plug a USB mic like the UMIK-1 (or an iMM-6 on a phone), select it as input, and load its calibration file with the “Mic profile” button. The curve is then corrected with the manufacturer's data — the file is read locally and never uploaded.
What do I do with the EQ suggestions?
They are peaking filters (frequency, negative gain, Q) that tame the detected modal peaks. Copy them into Equalizer APO, REW, a miniDSP or your AVR's PEQ. Only cut peaks: nulls are cancellations that EQ cannot fill — those need repositioning or bass traps.
Why do my results change between runs?
Small mic movements change the standing-wave pattern at the mic position — that's room acoustics, not a bug. Keep the mic in the same spot, run a longer sweep for noisy rooms, keep quiet during the measurement, and compare like with like.