I want to do spectral analysis of a k-rate signal giving me amplitude and frequency value pairs in spectral bands, like a phase vocoder, but only in a certain low-frequency range, e.g. 0-250Hz.
I could of course upsamp and do a pvanal of that, and then just disregard everything above the range I am interested in.
But that seems like a waste of CPU.
Is there a way to do this, e.g. using the fft family of opcodes which operates on arrays?