Checked September 2026
Voxengo
SPAN review
EQFree version
Free real-time FFT spectrum analyzer for professional mixing and mastering. Best for visual frequency and loudness analysis while mixing or mastering. Price: Free.
Key features
- FFT spectrum analysis with adjustable block size and overlap
- Multi-channel analysis (stereo, mono, mid-side, 5.1/7.1)
- Stereo correlation metering
- EBU R128 and K-system loudness metering
- True peak detection and clipping indicator
Pros
- Industry-standard free analyzer used across countless mixing/mastering chains.
- Extensive metering (correlation, loudness, true peak) beyond basic spectrum display.
Cons
- Analysis-only tool; does not process or shape audio itself.
- 64-bit only, no 32-bit builds listed.
SPAN alternatives
A free parallel dynamic equalizer combining parametric EQ with full dynamics processing.
VST3supportedAUsupportedAAXsupportedCLAPnot supportedWINsupportedMACsupportedLNXnot supportedPrecision EQ plug-in with up to 24 bands, dynamic EQ, and spectral dynamics processing.
VST3supportedAUsupportedAAXsupportedCLAPsupportedWINsupportedMACsupportedLNXnot supported- FREE
Kilohearts
Kilohearts Essentials
Free collection of over 30 effects usable as DAW plugins or Snapins.
VST3supportedAUsupportedAAXsupportedCLAPnot supportedWINsupportedMACsupportedLNXnot supported
Sources: www.voxengo.com