Tech Tools / RTA
RTA & Feedback Finder
A real-time analyzer in your browser. Open the mic, watch the spectrum, and let it call out the frequency that's ringing before the room hears it.
Works offline. Once this page has loaded, you don't need internet to use it. Audio is analyzed on your device and is never recorded or uploaded. Built-in laptop and phone mics aren't measurement mics, so read levels as relative unless you calibrate with a measurement mic and SPL meter. Feedback detection is a guide: sustained notes and test tones can trigger it, so confirm by ear.
Use Chrome or Edge. They give the cleanest raw mic signal and are what we test on. Safari works but may keep some voice processing on. Firefox can fail to open some mics; if it does, switch to Chrome or Edge.
Press Start and allow the microphone. Tap or drag on the graph to read any frequency.
Feedback now
Room tuning
A relative 1/3-octave EQ starting point, not an automatic system alignment. Use a calibrated measurement mic for trustworthy results.
1. Play pink noise
Send pink noise from the generator above or your console through the PA. Start low, mute unused live mics, and keep the test level steady. Don’t use white noise, a tone or a sweep for this measurement.
2. Measure several positions
Place the mic at ear height in the listening area, away from walls. Keep it still for each 6-second average, then move to another representative seat. Positions are power-averaged equally.
No positions measured. The microphone starts when you measure.
3. Review the suggested EQ
EQ can’t fix low-frequency nulls or room reflections. Boost sparingly. Check speaker placement, polarity, delay and coverage first. Apply either graphic EQ or the parametric approximation—not both—then remeasure.
● Measured● Target● Predicted (parametric)
31-band graphic EQ
Changes below 1.5 dB are ignored. Cuts stop at −12 dB. A dash means outside the selected or measurable range.
| Frequency | Change (dB) |
|---|
Parametric approximation
Up to 8 grouped peaking filters. Predicted response uses their actual combined curves. No EQ is applied in this browser.
| Frequency | Gain | Q |
|---|
Ring-out log
| Frequency | Note | Suggested cut | Hits · last |
|---|
How the feedback finder works
Feedback is a single frequency that holds steady and keeps building. The finder looks for a narrow peak that stands well above the spectrum around it, stays put for about half a second, and isn't fading. When it finds one, it marks it on the graph, names the frequency and musical note, and suggests a narrow EQ cut.
Measuring room response
Pink noise has equal power per octave and reads approximately flat in the 1/3-octave view. White noise rises about 3 dB per octave. Send the output to the PA, not just a laptop speaker. Measure several seats; the tool averages power, references 500 Hz–2 kHz, and suggests limited EQ. Verify after applying changes. A sine sweep is a test signal, not a transfer-function or impulse-response measurement.
Ringing out a room
With mics in place, slowly raise the system gain until the first ring. Note the frequency, apply a narrow cut of 3 to 6 dB, then keep going. The log collects every frequency that rang so you have the list ready for the show.
FAQ
Can it generate tones and sweeps?
Yes. Choose pink or white noise, a 20 Hz–20 kHz sine tone, or a log/linear sine sweep with optional looping. Output uses your selected speakers or connected interface. Press Play to start; keep the PA low.
Will it make my room perfectly flat?
No. It estimates relative EQ from steady pink noise. Mic response, background noise and reflections affect it; don’t boost deep nulls. Use suggestions as a starting point and remeasure.
Does it need internet?
No. After the page loads once it's saved on your device and opens without a connection.
Is my audio recorded?
No. Everything is processed in the browser and nothing is sent anywhere.
Can I use a calibration file?
Yes. Load the frequency and dB text file that came with your measurement mic. The correction is applied to the graph, feedback finder and room measurements. Changing calibration clears room positions so different curves aren’t mixed. Then set the calibration offset against an SPL meter to read true SPL.
Which browser works best?
Chrome or Edge. They give the cleanest raw mic signal. Safari on iPhone and iPad works but may keep some voice processing on. Firefox can have trouble opening some microphones, so use Chrome or Edge if it doesn't start.
Want it tuned for you?
Kynetic tunes PA systems for corporate and medical shows.