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Room Frequency Analyzer

Play pink noise or a log sweep through your speakers, capture it with your microphone, and see your room’s relative frequency response — resonant peaks, nulls, and low-frequency room modes — with treatment hints.

ℹ This is an uncalibrated guide. What you measure is your speakers + room + microphone combined, at one listening position — not the room alone. Laptop and phone mics colour the sound and roll off the deep bass, so trust the shape (big peaks, deep nulls, mode pile-ups) rather than exact dB, and ignore very-low-bass readings on a built-in mic. Measure from your seat, with your speakers playing into the room (don’t use headphones). For accurate work use a calibrated measurement mic and software like REW. The test signal plays through your speakers; the mic is analyzed live and never recorded or uploaded.

Microphone is off. Set a comfortable level, click “Start measuring”, and keep the room quiet while it plays.

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How It Works

This room frequency analyzer sends a known test signal to your speakers and measures what comes back through the microphone. In pink-noise mode it plays continuous pink noise (equal energy per octave) and builds a long-term average of the captured spectrum, then removes pink’s natural −3 dB/octave tilt so a perfectly flat speaker+room+mic would read as a flat line. In sweep mode it plays a single 20 Hz→20 kHz logarithmic frequency sweep and peak-holds the response at each frequency as the tone passes. Either way the curve is smoothed to about one-sixth of an octave and normalised to its own average, so it shows relative deviations, not absolute level. Sharp bumps are resonances and dips are cancellations; below roughly 300 Hz these are usually room modes (axial, tangential, and oblique standing waves) set by the room’s dimensions. Enter your room size and the tool overlays the predicted axial modes (f = n·c/2L) so you can see which peaks line up with them. If you want a full breakdown including tangential and oblique modes, the room mode calculator handles all three types and lets you compare your room’s modal distribution against ideal ratios.

Because there is no calibration, the vertical scale is relative and the absolute accuracy depends entirely on your microphone and speakers. A built-in laptop or phone mic has its own frequency-dependent sensitivity and very little true deep-bass response, so treat sub-100 Hz readings with caution and compare changes on the same setup. For quantitative work, a calibrated USB measurement microphone (such as a Dayton EMM-6 or miniDSP UMIK-1) dramatically improves low-frequency accuracy. Used sensibly, this analyzer is great for finding the big problems: a boomy modal peak, a deep null at the listening seat, or an obviously bright or dull tonal balance — the things that physical treatment and speaker/seat positioning actually fix. Once you know where the peaks are, the room EQ advisor converts them into ready-to-use parametric cut filters you can dial straight into your DSP or DAW.

Between pink noise and the log sweep, each has its strengths. Pink noise with the real-time RTA is better for comparing before and after a physical change (move a bass trap, shift a speaker) because the display updates continuously as you work. The log sweep is cleaner for capturing a single stable picture of the full room response, especially in rooms with significant background noise, since the peak-hold integrates the swept signal more robustly than a short RTA average. For a thorough room survey, consider taking measurements at multiple seat positions across the listening area: a peak that moves or disappears between positions is a mode; one that stays fixed is a speaker/EQ issue.

Frequently Asked Questions

Is this as accurate as REW with a measurement mic?
No. This is an uncalibrated guide using whatever mic you have, so the vertical scale is relative and the deep bass is unreliable on built-in mics. It’s for spotting gross problems; for precise work use a calibrated USB measurement mic and software like Room EQ Wizard (REW).
Should I use headphones?
No — this measures your room, so the test signal must play through your speakers into the room while the mic listens at your seat. Headphones would defeat the purpose.
What are room modes?
Standing waves between parallel surfaces. The lowest (axial) modes sit at f = n·c/(2·distance) for each room dimension, and they cause the biggest low-frequency peaks and nulls. Enter your room size to overlay them on the curve.
Is my microphone recorded or uploaded?
No. The mic is analyzed live in your browser and never leaves your device. Only the test signal is produced as sound. Stopping releases the mic immediately.
A null can't be fixed with absorption — why?
A null is acoustic cancellation at a point, not excess energy, so absorbing more does little. Moving your seat or the speakers/subwoofer out of the cancellation usually helps far more than treatment.
Should I use pink noise or the log sweep for measuring my room?
Pink noise (RTA) is better for live comparison — move a bass trap or speaker and watch the curve update in real time. The log sweep gives a cleaner single-shot picture in noisy rooms because the peak-hold integrates the swept tone more robustly than a short running average. For a one-off room survey use the sweep; for iterative treatment experiments use pink noise so you can see each change immediately.
How many measurement positions should I use?
At minimum, measure at your primary listening seat. Measuring 3–5 positions spread across the listening area is more revealing: a peak that moves frequency between positions is a room mode; one that stays fixed is a speaker or EQ issue. A null that disappears just 30 cm to one side is a cancellation you can escape by repositioning — far more useful information than a single-point curve can give you.
What should I do after finding peaks and nulls?
For peaks below about 300 Hz (room modes), the first step is physical: add bass traps at corners and wall-ceiling boundaries where modal energy concentrates. For residual low-frequency peaks that persist after treatment, apply parametric EQ cuts — the room EQ advisor generates specific filter settings (Fc, gain, Q) directly from a measurement. Nulls should not be EQ'd; instead, experiment with speaker and listening-seat placement to move out of the cancellation zone.