Voxengo SPAN is a free spectrum analyzer that shows the frequency balance of your audio in a real-time graph. When you wonder in a mix, “Is there too much low end?” or “Is the top end lacking?”, it gives you a way to check with your eyes as well as your ears. This page covers how to get it, its features and how you might use it.
Disclosure: this site uses affiliate programs. The fact that SPAN is free, and its features and formats, were checked on the maker’s official page around 2026-10-16. Terms of distribution can change, so please check the official page before you download.
How to get Voxengo SPAN
- Open the Voxengo SPAN official page (free).
- On Mac, download from the “Download AU, AAX, VST3 for Mac” link; on Windows, from the “Download VST, VST3, AAX for Windows” link.
- Run the installer you downloaded. The official page has a link with installation guidance titled “How to install this free software?”.
- Open your DAW (recording and production software) and rescan your plug-ins.
- Load SPAN on the insert of the track or master you want to monitor.
We could not find any request for account registration on the official page.
What kind of product is Voxengo SPAN?
The maker describes SPAN as a “free real-time FFT audio spectrum analyzer”. FFT (Fast Fourier Transform) is a calculation method that splits sound by frequency and measures the strength of each part. As a plug-in, it is described as running in AAX, AudioUnit and VST formats.
SPAN lets you fine-tune how the display looks through its “modes”. You can set the FFT block size, the window overlap rate and the slope of the graph, and the maker explains that you can also overlay a second spectrum (such as a real-time maximum or an all-time maximum). There are also functions that visually smooth the spectrum so it is easier to read, and a function to choose colors to your taste.
Main features
- FFT spectrum analyzer (per the manufacturer): Shows stereo, mono and mid-side (a method that separates the center from the left-right difference) spectrums.
- Surround support (per the manufacturer): It is described as usable as a 7.1 and 5.1 surround spectrum analyzer too.
- Compare several channels at once (per the manufacturer): Supports multi-channel analysis and can show the spectrums of two different channels (or groups of channels) at the same time.
- Built-in level meters (per the manufacturer): Supports RMS, true peak and clipping detection, and lets you adjust the meter response speed and integration time. EBU R128 and K-System meters are also included.
- Stereo correlation meter (per the manufacturer): Comes with a correlation meter for checking the phase relationship between left and right.
- Level statistics (per the manufacturer): Level statistics, a headroom estimate and true-peak clipping detection are also described as being displayed.
- Color variations (per the manufacturer): The official page shows examples of the display in different colors.
Who it may suit
- People who want to check frequency balance with their eyes as well in mixing and mastering
- People who want to compare the frequencies of their own mix with a reference track
- People who want to find a build-up of low end or a lack of high end
- People who are concerned about stereo phase (differences between left and right)
- People who want a level meter alongside, for free
Tips for using it
- SPAN is a tool for looking, not for changing the sound. The final decision is made with your ears; the basic way to use the graph is to “find where the part that bothered your ears is”.
- Placing it at the very end of the master track (after the other effects) lets you view the balance of the whole song.
- Another way to use it is to put it on a vocal or instrument track and look for “bands that sound muddy” or “bands that hurt the ears”. It might give you a clue about where to cut with an EQ.
- If you load a song you want to use as a reference into the same DAW and compare it in SPAN while playing, you can get hints about which bands are too strong or too weak in your own mix.
- With the mid-side display, you can look separately at the sounds gathered in the center and the sounds spread to the left and right.
- If the graph moves too finely to read, try adjusting the spectrum smoothing setting or the slope setting.
Things to know before you download
The place and terms of distribution for free plug-ins can change. Before you download, check the latest information on the official page.
- Supported formats: The official page lists AU, AAX and VST3 for Mac, and VST, VST3 and AAX for Windows.
- Supported OS: 64-bit Mac OS and Windows PCs are listed as supported.
- Supported hosts: Ableton Live, Cubase, Logic Pro, REAPER, Pro Tools, FL Studio, Studio One, OBS, Bitwig Studio, Nuendo, WaveLab, Cakewalk, Adobe Audition, GarageBand and others are named (part of the official list).
- Paid version: The Voxengo website also lists “SPAN Plus” (a spectrum analyzer) as a separate product. The SPAN introduced on this page is the one distributed for free.
- Always get the file from the official website.
FAQ
Q. Are there feature limits even though it is free?
The official page says “SPAN free”, and it is distributed for free. For the differences in features from the paid SPAN Plus, please check each product’s page.
Q. Does installing SPAN change my sound?
SPAN is a meter product that analyzes and displays sound. Its role is different from an EQ or compressor that processes the sound.
Q. Aren’t my ears enough?
Your ears still come first. However, how things sound can change with your monitoring environment and ear fatigue, so many people use a graph alongside to check.
Voxengo SPAN is available from the Voxengo official website (free).
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