Spectrum Analyzer Online

How do you compare a mix to a reference track?

1. Load a bounce in the Mix well. WAV is a good choice if you have it.
2. Add a reference with a similar arrangement and a tone you know well.
3. Leave loudness matching on. The solid amber line is your mix; the pale dashed line is the reference.
4. Start with 1/3 octave smoothing for the broad balance. Try 1/6 or 1/12 to examine narrower features.
5. Read the difference curve and the band summary, then listen for the same difference in your DAW.

For a fair comparison, export similar sections from both songs. A sparse intro and a full chorus can pull the average in different directions.

How do you read a spectrum analyzer for mixing?

A spectrum analyzer shows how an audio signal's energy is distributed across frequency. Low frequencies sit on the left, high frequencies on the right. A higher curve means more energy in that region. The horizontal axis is logarithmic, so the distance from 100 to 200 Hz is the same as from 1 to 2 kHz.

This online frequency analyzer shows a long-term average first. It helps you see broad balance without chasing every kick or consonant. Hover, touch, or use the arrow keys on the graph for frequency, nearest note at A4 = 440 Hz, and level. The note is a frequency label, not a detected musical key.

The lower curve subtracts the reference from the mix. A positive value means the mix has more energy there; a negative value means less. It has its own dB scale. For examples of using an analyzer before and after EQ, read how to read a spectrum analyzer.

Why compare at matched loudness?

A louder reference lifts nearly its entire curve. That makes a simple level difference look like your mix needs more of everything. Matching integrated LUFS shifts the reference to the mix's measured loudness before the curves are compared.

This makes broad tonal differences easier to judge, but does not match dynamics or arrangement. A heavily limited master can still behave differently from an open mix. Use the loudness meter to examine loudness range and peaks separately. Matching here affects the reference display only; the listening-level control affects mix playback only.

What do the frequency bands mean?

• Sub, 20-60 Hz: the lowest weight of a kick, bass or synth. Small speakers may not reproduce it.
• Bass, 60-250 Hz: much of the low-end body and punch. Listen to how the kick and bass share it.
• Low-mid, 250-500 Hz: warmth and body, but also buildup when several instruments overlap.
• Mid, 500 Hz-2 kHz: much of the character of voices, guitars, keys and other instruments.
• Presence, 2-6 kHz: articulation and attack. Too much can feel tiring, depending on the source.
• Air, 6-20 kHz: cymbal texture, breath and upper harmonics. More is not always better.

These are working names with approximate boundaries. The EQ frequency chart maps instrument ranges and notes to the same 20 Hz-20 kHz axis.

What should you avoid?

• Chasing a flat line. Music has its own spectral shape. On this power-per-hertz display, even pink noise slopes downward.
• Mixing only by eye. A visible peak may be the useful fundamental of a note. Listen before cutting it.
• Copying a different arrangement. A reference with an extra sub synth will have more low-end energy for a reason.
• Comparing different analyzer settings. Window size, smoothing and display scaling change how a curve looks.
• Treating the summary as an EQ prescription. A 3 dB band difference is an observation, not an instruction to boost or cut 3 dB.

How does the measurement work?

A worker splits the decoded file into Hann-windowed FFT frames with 50% overlap, adding a final frame at the end when needed. It averages linear power over time and across channels, then converts it to dBFS per hertz. Stereo channels are measured separately, so opposite-polarity material does not cancel out in the average.

FFT bins are at most 3 Hz apart for a full window. Short files are zero-padded and have less frequency detail. Octave smoothing averages power across proportional frequency bands. The summary integrates wider bands from the unsmoothed result, ignores nearly empty bands, and lists up to three differences of at least 1 dB.

Integrated LUFS uses the same BS.1770 engine as our loudness meter, including its channel weights and gating. The spectrum includes all channels with equal weight; loudness excludes LFE and weights surrounds. The visible axis always spans 20 Hz to 20 kHz, but no curve is drawn beyond a file's Nyquist limit, half its sample rate.