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About Audio Spectrogram Viewer
The Audio Spectrogram & 3D Frequency Waterfall Analyzer computes Fast Fourier Transforms (FFT) across audio signals, displaying real-time 2D/3D heatmaps of frequency distribution (0Hz to 22kHz) over time, identifying audio cutoffs, lossy compression artifacts, and microphone noise.
How to Use Audio Spectrogram Viewer
Step 1
Upload an audio file (FLAC, WAV, MP3, OGG).
Step 2
Select color palette and FFT resolution.
Step 3
Inspect the frequency spectrum heatmap and inspect high-frequency boundaries.
Step 4
Click "Export Spectrogram Image".
Practical Use Cases for Audio Spectrogram Viewer
Detecting Fake "Lossless" FLAC Files (Frequency Shelf Analysis)
Inspect audio files claiming to be FLAC/WAV to verify if high frequencies abruptly cut off at 16kHz or 20kHz, proving they were upsampled from lossy MP3s.
Locating Unwanted Acoustic Hum & Microphone Interference
Pinpoint exact 50Hz/60Hz AC electrical hums or high-pitched 15kHz CRT coil whine frequencies for surgical EQ notch filtering.
Input & Output Examples
Analyzing 320kbps MP3 vs FLAC Spectrogram
Audio file: `suspect_track.flac` (FFT Size: `2048`)
Spectrogram reveals sharp hard cutoff at 16.0 kHz $\\rightarrow$ Confirmed fake lossless (upscaled from 128kbps MP3)
Key Features & Performance
- ✓High-resolution Short-Time Fourier Transform (STFT) with configurable FFT window sizes (512, 1024, 2048, 4096).
- ✓Color Palettes: Viridis, Inferno, Magma, Plasma, Grayscale, Cyberpunk Rainbow.
- ✓Frequency Scales: Linear (0-22kHz), Logarithmic (Musical Octaves), Mel Scale (Psychoacoustic).
- ✓100% Client-Side WebGL / Web Audio API analyzer.
- ✓1-Click Export Spectrogram PNG.
Key Terminology & Definitions
Spectrogram
A visual representation of the spectrum of frequencies of a signal as it varies with time, where the vertical axis is frequency, horizontal axis is time, and color is intensity (dB).
Frequency Cutoff / Shelf
The sharp horizontal line above which no audio frequencies exist, characteristic of lossy perceptual encoders (e.g. 128kbps MP3 cuts at 16kHz).