APU Software Spectrum Analyzer v5.1.7 STANDALONE VST3 AU AAX WiN MAC

APU Spectrum Analyzer is a free analysis tool that lets you see exactly what your audio is doing across the frequency range. It works as a standalone application or as a VST3, AU, or AAX plugin on both Windows and Mac, so it fits into most production setups. You can adjust the FFT window type—choosing from Rect, Hann, Hamming, Blackman, or Kaiser—and set the FFT size anywhere from 64 to 65536 samples to balance speed and detail. Real-time monitoring includes a variable history size, and you can also load an external audio file for full spectrum analysis. The display switches easily between standard dB ranges and auto-range, and you can view the spectrum on a logarithmic, linear, or note-based scale. A histogram hold feature helps you measure long-term frequency response, and you can adjust the bucket size independently of the FFT size. Snapshots let you save a reference frequency response for comparison. This tool is aimed at hobby producers who want a clear, customizable view of their mix without spending anything.