Voxengo SPAN Plus
As a Mixing and Mastering engineer, and also as a University professor, I have been testing different spectral analysis plugins for years. Without a doubt, Voxengo Span Plus has all the features that an audio engineer requires when performing a detailed analysis of any type of signal. Its design is very intuitive, and totally versatile.
As usual, Voxengo has been carefully behind every detail in the design of Span Plus.
I think Span Plus is my best partner when it comes to mixing or mastering!
I have many FFT and spectrum display programs (at least 12 on this machine).
I was, once again, looking to generate some noise profile images for a report and in frustration, went back to the web looking for alternatives - I found Span Plus.
Several of the features make generating the presentation materials I need super easy and effective - taking the files into an editor/mixer so that I can use the plugin is completely offset be the ease of seeing what I need and capturing PNG files all within the software - I know it probably wasn't your intent to support the test and measurement industry, but it does!
Impressed enough that I just bought the Premium Membership and am looking forward to using the tools for their real intent - Music