Real-Time Spectrum Analyzer
Frequency Range Guide
About This Spectrum Analyzer
This real-time audio frequency spectrum analyzer uses the Web Audio API to visualize the frequency content of audio captured from your microphone. It performs Fast Fourier Transform (FFT) analysis to break down complex audio signals into individual frequency components.
How It Works
- FFT Analysis: Converts time-domain audio samples into frequency-domain data, showing which frequencies are present and their relative amplitudes.
- Real-time Visualization: Updates 60 times per second for smooth, responsive frequency display.
- Frequency Resolution: Higher FFT sizes provide more frequency bins and better resolution, especially at lower frequencies.
- Smoothing: Time-domain smoothing reduces visual fluctuations and makes patterns easier to see.
Common Uses
- Analyzing musical instruments and their harmonic content
- Testing room acoustics and identifying resonant frequencies
- Troubleshooting audio equipment and speaker frequency response
- Educational demonstrations of sound and frequency concepts
- Tuning audio systems and identifying frequency masking
- Visualizing voice characteristics and formants
Understanding the Display
The spectrum analyzer shows frequency on the horizontal axis (20 Hz to 20 kHz) and amplitude on the vertical axis. Each vertical bar represents the energy present at that frequency range. Taller bars indicate stronger frequency components. The display uses a logarithmic frequency scale to match human hearing, which perceives frequency ratios rather than linear differences.
Privacy Notice
All audio analysis happens locally in your browser. No audio data is recorded, transmitted, or stored. Your browser will request microphone permission, but the audio stream is only used for real-time visualization and is never saved.
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Audio Frequency Spectrum Analyzer FAQ
What is a frequency spectrum analyzer?
A frequency spectrum analyzer visualizes the amplitude of different frequencies present in an audio signal. It uses FFT (Fast Fourier Transform) to break down complex audio into individual frequency components, displaying them as bars or lines where height represents amplitude.
What is FFT size and how does it affect analysis?
FFT size determines the frequency resolution of the analysis. Larger FFT sizes (like 4096 or 8192) provide better frequency detail but slower response time. Smaller sizes (like 512 or 1024) update faster but have less frequency precision. 2048 is a good balance for most uses.
What frequency ranges can humans hear?
The human hearing range is approximately 20 Hz to 20,000 Hz (20 kHz). Sub-bass is 20-60 Hz, bass is 60-250 Hz, low-mids are 250-500 Hz, mids are 500-2 kHz, upper-mids are 2-4 kHz, presence is 4-6 kHz, and brilliance is 6-20 kHz.
How accurate is browser-based frequency analysis?
Browser-based frequency analysis using the Web Audio API is quite accurate for most purposes. It uses the same FFT algorithms as professional audio software. Accuracy depends on sample rate (typically 44.1 or 48 kHz), FFT size, and microphone quality.