Voxengo SPAN
Voxengo · Free
Voxengo SPAN is a free real-time FFT spectrum analyzer plugin with multi-channel modes, correlation metering, and EBU R128 / K-system level tools.
The free spectrum analyzer most mix rooms still reach for first—flexible, honest metering without a subscription or trial wall.
Best for: Producers and engineers who need reliable FFT analysis and basic loudness/correlation checks for free.
Pros
- Free commercial-use FFT analyzer with serious flexibility
- Stereo, mid-side, and surround analysis modes
- EBU R128, K-system, RMS, true peak, and correlation metering
- Configurable FFT size, slope, smoothing, and secondary spectrum
Cons
- Utility-only — it does not process or fix audio
- Interface is dense and utilitarian compared with modern GUI meters
- Paid SPAN Plus exists if you outgrow free SPAN
Overview
Voxengo SPAN is a free real-time FFT spectrum analyzer that became a default insert on mix and master buses long before loudness meters went mainstream. It does not compress or EQ anything. It shows you what is happening in the frequency domain, with enough metering extras to catch level and correlation problems while you work.
It excels at flexible analysis. Modes cover mono, stereo, mid-side, and multi-channel layouts including surround. You can set Fourier block size, window overlap, visual slope, smoothing, and a secondary spectrum (for example real-time or all-time maximum). Output metering adds adjustable ballistics, EBU R128 and K-system scales, true peak clipping detection, headroom estimates, and correlation. That combination is why SPAN still appears in free-plugin roundups years after launch.
The trade-off is purpose. SPAN will not replace a full suite like Insight 2 for detailed loudness workflows or client reports. The UI prioritizes function over fashion. If you only need LUFS targets for streaming, Youlean Loudness Meter may feel more focused. If you need tonal target curves, Tonal Balance Control or REFERENCE aim at different jobs.
Choose SPAN as a free always-on analyzer. Graduate to Insight 2 or Youlean Pro when you need deeper metering features. Download only from the official Voxengo product page.
Specifications
- Type
- FFT spectrum analyzer / metering utility
- Price
- Free
- Formats
- VST, VST3, AU, AAX (64-bit)
- Platforms
- Windows and macOS
- Metering
- EBU R128, K-system, RMS, true peak, correlation
- Manual
- Official SPAN user guide PDF on Voxengo site
Last verified 2026-07-16
FAQ
Is Voxengo SPAN free for commercial music?
Yes. SPAN is free software from Voxengo for professional audio and music production. Always confirm the current license terms on the official Voxengo page.
What formats does SPAN support?
SPAN is available as AAX, Audio Units, VST, and VST3 for 64-bit hosts on macOS and Windows.
SPAN vs Insight 2 — which should I use?
SPAN is free and excellent for spectrum and basic meters. Insight 2 is a paid full metering suite with deeper loudness, surround, and reporting tools.
Direct competitors
Voxengo SPAN vs — head-to-head specs, price, and Dubspot Score.