I'll be posting VST plugins that I use including some tips on application in Au. Spectrum Analyzer VST by seven-phases
This is a Really Good Spectrum Analyzer that I found recently by "Accident"
Au's native analyzer(s) are Curve, Curve-Fill, Bars and Spectral. I prefer bar-graph type analyzers and I feel this one is superior to Au's.
And it's open source.
From the author(s): ''Seven Phases Spectrum Analyzer is a real-time spectrum analysis VST plugin. The idea was to create an
old-fashioned tool reminiscent of classic hardware analyzers of the earlier centuries. Unlike most of other
analyzers available these days, this plugin is not FFT-based but utilizes a filter-bank algorithms that mould its
unique pros and cons.''
This final release (v1.09-beta) was in 2015 the "Sweet Spot" for XP compliant VSTs IMO.
I don't know what happened to the development.
Arguably the best freeware Spectrum Analyzer ever...(?)