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Voxengo SPAN
What it is
Voxengo SPAN is a free real-time FFT spectrum analyzer plugin for audio and music production applications. It can analyze stereo, mono, mid-side, and surround signals, including 5.1 and 7.1. Metering includes EBU R128 and K-system readings, RMS and true-peak measurements, clipping detection, and stereo correlation. Users can adjust FFT block size, window overlap, visual slope, smoothing, and a secondary spectrum display. Multi-channel analysis can show spectra from two channels or channel groups at once. Other tools include channel routing and grouping, output power statistics, presets, undo and redo, and A/B comparisons. SPAN is available for Windows and macOS in VST, VST3, AAX, and AudioUnit formats, with formats varying by system. The maker lists Windows XP and later, macOS 10.12 and later, a 2.5 GHz dual-core or faster processor, and at least 4 GB of RAM. Spectrum import and export for track comparisons is a SPAN Plus feature; the free-plugin method works only in some hosts.
For and against
For
- Analyzes stereo, mono, mid-side, and surround signals.
- Includes EBU R128 and K-system metering.
- Measures RMS and true peak, and detects clipping.
- Displays spectra for two channels or channel groups.
- Offers VST, VST3, AAX, and AudioUnit compatibility.
Against
- Spectrum import and export for track comparisons is a SPAN Plus feature.
- The free-plugin comparison method works only in some hosts.
- The maker specifies at least 4 GB of RAM.
- Plugin formats differ between Mac and Windows.
The verdict
SPAN provides real-time spectrum analysis with several metering and channel-view options at no cost. Users who need spectrum import and export for track comparisons should note that this is a SPAN Plus feature.
Who it suits
SPAN suits audio and music production users who want real-time spectrum analysis and level metering in a plugin. It supports a range of channel configurations and plugin formats.
Plans and prices
Voxengo SPAN free
Freeware FFT analyzer · requires compatible audio host · Windows/macOS plugin formats
Read 15 Oct 2026 · voxengo.com
Voxengo SPAN
Free real-time FFT spectrum analyzer plugin
Read 3 Oct 2026 · voxengo.com
On the record
- Additional features
- The feature list includes spectrum smoothing, resizable interface, output signal power statistics, channel routing and grouping, preset management, undo/redo, and A/B comparisons.voxengo.com · read 3 Oct 2026
- Analysis modes
- It provides stereo, mono, mid-side, and surround spectrum analysis, including 5.1 and 7.1.voxengo.com · read 3 Oct 2026
- API and SDK
- The documentation describes SPAN as a plugin loaded by AudioUnit, AAX, VST, or VST3 hosts and does not specify a public API or SDK.voxengo.com · read 15 Oct 2026
- Authorization
- Free Voxengo plugins do not require a product key or online authorization.voxengo.com · read 15 Oct 2026
- Correlation meter
- SPAN includes stereo-correlation metering for checking phase and mono compatibility.voxengo.com · read 15 Oct 2026
- Current version
- The downloads index lists SPAN version 3.24 released April 4, 2026.voxengo.com · read 15 Oct 2026
- Documentation
- The product page links English, French, German, and Russian user guides, including a seven-page English PDF covering spectrum, statistics, metering, and correlation.voxengo.com · read 15 Oct 2026
- Downloads
- Separate Mac and Windows downloads are offered; the product page lists AU, AAX, and VST3 for Mac and VST, VST3, and AAX for Windows.voxengo.com · read 3 Oct 2026
- FFT configuration
- Users can set Fourier block size, FFT-window overlap, visual slope, secondary-spectrum type, and smoothing.voxengo.com · read 15 Oct 2026
- Formats
- Official downloads provide VST, VST3, AudioUnit, and AAX builds.voxengo.com · read 15 Oct 2026
- Host integrations
- Listed compatible hosts include Ableton Live, Cubase, Logic Pro, REAPER, Pro Tools, FL Studio, Studio One, OBS, Bitwig Studio, Nuendo, and Adobe Audition.voxengo.com · read 3 Oct 2026
- Installation model
- The primary guide says each platform and plugin specification is distributed in a separate archive or installer containing the binary, documents, license agreement, and change history.voxengo.com · read 15 Oct 2026
- Integrations
- Listed compatible hosts include Ableton Live, Cubase, Logic Pro, REAPER, Pro Tools, FL Studio, Studio One, OBS, Bitwig, Nuendo, WaveLab, GarageBand, and others.voxengo.com · read 15 Oct 2026
- Known limitation
- Voxengo says importing and exporting spectra for easy track comparisons is a SPAN Plus feature and that the free plugin method works only in some hosts such as Ableton Live.voxengo.com · read 3 Oct 2026
- License
- Voxengo software is copyrighted proprietary software governed by an accompanying end-user license; redistribution is prohibited unless that license permits it.voxengo.com · read 15 Oct 2026
- Limit: learning curve and scope
- An independent 2026 review described the interface as utilitarian, warned that beginners can misread FFT and slope settings, and noted that SPAN analyzes problems rather than correcting them.michaelmusco.com · read 15 Oct 2026
- Limit: multi-channel setup
- Bonedo said the multi-channel function was not immediately intuitive.bonedo.de · read 15 Oct 2026
- Limit: no standalone operation
- Independent coverage describes SPAN as a plugin for Windows and macOS hosts rather than a standalone audio editor or mastering application.audiopluginlist.com · read 15 Oct 2026
