Blue Cat s FreqAnalyst
'what you cannot hear, blue cat s freqanalyst shows it to you, for free. Blue cat s freqanalyst is a free spectrum analyzer plug-in that lets you monitor the spectral content of your audio signal in real time. This plug-in has been designed to provide extreme smoothness and high resolution for both time and frequency: unlike most spectrum analyzers, blue cat s freqanalyst is able to display continuous variations even with a very high frequency resolution, thanks to its unique smooth interpolation algorithms.
Most aspects of the audio to frequency display conversion can be managed, which lets you total control over the monitoring. A special thresholding system has been developed to help you see the important parts of the spectrum easily. In case you need extra precision in a particular frequency range, you can zoom the display and check the part of the graph you are interested in.
This plug in supports blue cat s skinning language, so that you can customize the user interface to your personal needs
For more advanced capabilities, check blue cat s freqanalyst pro plug in, an extended version that offers many more features, such as saving/restoring curves, precise measurement tools, 3d spectrogram view, midi output
For multiple tracks analysis, you can use blue cat s freqanalyst multi plug in