Measurement AccuracyA built-in microphone is not a measurement device. Results are indicative only — for accurate analysis use a calibrated measurement microphone.
RMS
—dB
Peak
—dB
Spectrum (FFT)
Spectrogram
About this tool
The Spectrum Analyzer shows microphone audio in real time: an instantaneous FFT spectrum, a time-accumulating spectrogram, and live RMS and peak levels in decibels. It is a basic tool for quickly assessing the room's noise spectrum, finding ringing frequencies, checking tonal material, or watching for hum and background interference.
Why it matters: hearing a problem does not always tell you at what frequency it sits. The spectrum and spectrogram give a visual fingerprint of the sound — a peak at 60 Hz suggests mains hum, a dark horizontal band at 100–120 Hz points to room boom, a slowly decaying "tail" on the spectrogram indicates long reverberation. Two capture modes are available: infinite (the user stops the measurement) and until-spectrogram-fills (fixed duration).
How to read results: on the spectrum, horizontal axis is frequency and vertical axis is instantaneous level. On the spectrogram, horizontal is time, vertical is frequency, and color is loudness. RMS shows the average level; peak shows the instantaneous maxima. If peak hits 0 dB the signal is clipping and the analysis is distorted.
Limitations: a built-in laptop or phone microphone is not measurement-grade. The numbers show ballpark levels and a relative spectral picture, not certified acoustic measurements. For RT60, NC, or room transfer-function measurements use a calibrated microphone and specialized software (REW, Smaart).
Next steps: to evaluate room resonant frequencies use the Room Modes calculator; for reverberation time use RT60; for treatment design use the Treatment Planner and absorber calculators.
