What should my mic level look like on the meter?
For speech recording or streaming, RMS should sit between -30 and -18 dBFS during normal talking, with peaks staying below -3 dBFS to leave headroom. Quieter than -30 dBFS means you will pick up too much room noise relative to voice; louder than -12 dBFS RMS risks clipping on sudden loud syllables. Singers and shouters need more headroom — aim for -24 dBFS RMS. Adjust gain in your OS sound settings or interface preamp, not in the application. Check your noise floor at https://devicecheckonline.com/microphone/noise.
What does the spectrum analyser actually show?
It plots energy across frequency bands from roughly 20 Hz on the left to your sample rate divided by two (typically 24 kHz at 48 kHz sample rate) on the right. Speech concentrates between 100 Hz and 4 kHz with peaks around 200 Hz for males and 350 Hz for females. A loud bump below 80 Hz is rumble — HVAC, computer fan, footfall — and should be high-passed. A spike at 50 or 60 Hz with multiples is electrical hum, usually a ground loop or USB power problem. A flat shelf across 8–15 kHz that never moves is broadband digital noise.
Why does my microphone work in this test but not in Zoom or Discord?
Browsers and applications each request microphone access independently. This page uses getUserMedia and bypasses noise suppression so you see the raw signal, while Zoom, Discord, and Teams apply their own gain, gating, and AI noise reduction that can mute quiet voices entirely. Common fixes: check the per-application microphone permission in OS Privacy settings, set the correct default input device, disable application-level 'Auto Adjust Mic Sensitivity', and close any other app holding the mic exclusively. Confirm gating thresholds with https://devicecheckonline.com/microphone/gate.
What is the difference between RMS and peak?
Peak is the loudest single sample in the last few milliseconds — it spikes on consonants, plosives, and any transient. RMS is the average power over a sliding window (200 ms here) and tracks perceived loudness, the thing meters in your DAW or LUFS measurements care about. Peaks 6–12 dB above RMS is normal for clear speech. If peak and RMS are nearly identical, your signal is over-compressed by the OS or hardware. If peaks are 20+ dB above RMS, you have a plosive problem — use a pop filter or move off-axis.
Why is the waveform clipped flat at the top and bottom?
You are clipping the analogue-to-digital converter. The signal exceeded full scale and was hard-limited to 0 dBFS, producing the squared-off shape. Reduce input gain in your OS sound settings, move further from the mic, or engage the -10 or -20 dB pad on your interface. Recorded clipping cannot be repaired — declipping plugins guess at the missing waveform. Verify true peak headroom with the LUFS meter at https://devicecheckonline.com/microphone/lufs.
Does this test work on phones and Bluetooth headsets?
Yes on phones — Safari, Chrome, and Firefox on iOS and Android all support getUserMedia and will prompt for mic permission. Bluetooth headsets are trickier: when active, the OS often forces HFP/HSP mode at 8 or 16 kHz sample rate, which is why your voice sounds tinny in Discord. The spectrum will visibly cut off above 4 kHz in that mode. Wired or USB mics give the cleanest signal. Always grant microphone permission to the browser before clicking start.