Advice for low frequency & high fft bins

[SpikedCola]

Hi,

First, big thanks for your work on this project. It was really easy to get going out of the box and works well!

I am trying to visualize just the sub-bass, so I've set min_frequency to 20 and max_frequency to 200, n_rolling_history to 2, and n_fft_bins to 40. I'm expecting 40 buckets/peaks with ~5Hz in each. Instead I only see 6 buckets:

If I adjust n_rolling_history, eg. by setting to 3 instead of 2, I get a couple more bins:

Any advice? Thanks again!