SPAN is a real-time “fast Fourier transform” audio spectrum analyzer, AU and VST plugin for professional music and audio production applications. For the most part it was derived from the Voxengo GlissEQ dynamic parametric equalizer and reproduces its spectrum analysis functionality. SPAN provides you with a very flexible “mode” system which you can use to set up your spectrum analyzer preferences. You may specify a Fourier block size in samples, the FFT window overlap percentage, and the spectrum's visual slope. Beside that, you can choose to display a secondary spectrum of a desired type (e.g., real-time maximum, all-time maximum). Spectrum can be smoothed out visually for an easier examination.