Live Spectrum Analyzer

Knowledge Base

How to Use This Alongside the EQ Reference

The EQ Frequency Reference teaches you what each frequency band sounds like in isolation. This tool shows you what's actually present in a real signal (your voice, a mix, an instrument) in real time, so you can identify problem frequencies (a resonant boom, harsh sibilance, a buzzing hum) as they happen rather than only in theory.

Reading the Display

The x-axis is frequency on a logarithmic scale (matching how we perceive pitch), from roughly 20 Hz to 20 kHz. The bright, moving bars are the current spectrum. The fainter trailing line above them is peak-hold. The highest level each frequency has reached recently, useful for spotting a brief resonance or spike that the live display alone might flash past too quickly to catch.

Common Uses

• Finding the exact frequency of a room hum, mic buzz, or feedback squeal.
• Seeing where a voice's energy actually concentrates, compared to where you assumed.
• Checking whether a de-essed or EQ'd signal has actually reduced energy in the target band.

FAQ

Q: Why does the display look different for the same sound on different microphones?
A: Every microphone has its own frequency response. A bright condenser and a darker dynamic mic will show genuinely different spectra for identical source material, which is expected and part of why mic choice matters.

Q: Can I use this to check a whole song, not just live input?
A: Yes. Use "Load Audio File" to analyse an uploaded track's spectrum in real time as it plays back.

Reading a spectrum display

A spectrum analyser shows how much energy sits at each frequency at this instant. Low frequencies appear on the left, high on the right, and height indicates level. Speech and music both look lumpy and constantly moving, which is normal. What matters is not the exact shape but the parts of it that stay still, because anything constant is usually something you did not intend to record.

A narrow spike holding steady at one frequency while nothing is happening in the room is almost always electrical. Fifty or sixty hertz, matching your mains supply, means hum from a ground loop or an unbalanced cable. A steady peak somewhere between 100 and 300 hertz in an untreated room is more likely a room mode, where a dimension of the room reinforces one particular frequency.

Use peak hold to find problems that pass too quickly to see. It keeps the highest level reached at each frequency on screen, so a single resonant ring or a brief burst of sibilance stays visible after the sound has gone. This is the fastest way to locate a specific offending frequency without repeatedly replaying the same passage.

Do not mix a spectrum with a frequency response target. A display showing more energy at low frequencies than high does not mean the recording is wrong, because most natural sound genuinely holds more energy down there. Compare a recording with a reference you trust rather than with a flat line, and trust your ears over the picture when the two disagree.

Give yourself a reference before trusting the display. Playing a track you know well through the same system shows how this room and these speakers colour what you see, so you learn to discount the peaks belonging to the room rather than to the material.

Vocabulary

Spectrum. A view of sound broken into its component frequencies, showing how much energy sits at each. Different from a waveform, which shows level over time and says nothing about which frequencies produce it.

FFT. Fast Fourier Transform, the calculation that converts a slice of audio into its frequency components. Every spectrum display runs one continuously. A longer slice gives finer frequency detail and slower response to change.

Room mode. A frequency reinforced by the dimensions of a room, where a sound wave fits its width, length or height and reflections add to it. Produces a fixed peak that follows the room rather than the microphone.

Peak hold. A display mode keeping the highest level reached at each frequency visible after the sound has passed. Useful for catching brief events too fast to see on a live display.