Maximum Number Of Bands For Spectrum Analyzer

[brandondrury]

It may be cost prohibitive, but I was just curious of the maximum # of bands that would be realistic for an Arduino-driven spectrum analyzer.  I see the 7-band spectrum analyzer frequently.  That's fine for a nice visual effect, but I wouldn't mind having one that actually had some purpose in my recording studio.  Off hand, I think 31 bands would be the bare minimum.  Is this possible with the Arduino?  What about 2 Arduinos?

Brandon

[retrolefty]

Well a true spectrum analyzer doesn't limit one to descrete bands but rather covers some continous frequency range. But it all comes down to the complexity of the external circuitry and components you utilize. The seven band design I saw used an external seven bandpass active filter IC device where the arduino was just measuring the voltage level output of each of the discrete bands, not true specturm information suitable for many of the measurement applications that need such an instrument.

Lefty

[Nantonos]

There is an Arduino implementation of a Fast Hartley Transform (FHT)] Fast Hartley Transform (FHT) over at Open Music Labs.

It can give you up to 256 frequency bins at 16b depth, at a minimum of ~3ms update rate. It is adjustable from 16 to 256 bins, and has several output methods to suit various needs. It can be set to 16b linear, 8b linear, 8b logarithmic, or 8b octave output.