I explored this options as well. In my testing I was able to get a factor of 6 speedup simply by reshaping a 1D array into 2 dimensions. The FFT on the 1D audi

I explored this options as well. In my testing I was able to get a factor of 6 speedup simply by reshaping a 1D array into 2 dimensions. The FFT on the 1D audio would not work because the FFT of a sub sample would not be immediately recognizable in the FFT of the whole. This is why I took the spectrogram approach, which is many FFTs over time.