Spectrum Analyzer bands

[takev]

Hello everyone,

I've been working on Boom Recorder 7.16 (I still have to make the new manual).

And this new version will include a spectrum analyzer.

I was wondering why the bands on a hardware based analyzer or graphic equalizer show bands that are based on a 1000 Hz center. 1000 looks like a pretty number, and multiplying it in your head is quite easy but it does not resemble a musical note which would be centered around 440 Hz.

Now what I am really puzzled about is that they picked 1000 Hz, but the increments are thirds, which again is pretty important for musical notes again.

I am just wondering about it.

Boom Recorder has many more bands, so it just shows grid lines. Right now the grid lines are centered around the 440 Hz, but I will add an option for 1000 Hz as well.

Cheers,

    Take

[Sergio Sanmiguel]

Human voice relates to 1 kHz, and 440hz relates to A note on a grand piano... It's probably that the relationship.

[Philip Perkins]

The main thing for an analyzer for location dialog use would be to have most of the visible scale cover the area from about 60 Hz to about 5K.  Many of the computer-app RTAs have displays that cover lots of detail in the high frequency area, which isn't of much interest to us, with the voice range squished down to a small area at the left of the scale.

Philip Perkins

[takev]

Philip,

Just like the other RTAs out there Boom Recorder also looses resolution in the lower frequencies.

Right now it slices the frequency spectrum up in 2048 linear pieces for a 48000 Hz sample rate that would be slices of 23 Hz per band. This all gets displayed on a logarithmic scale of course.

I could increase the resolution, but that will use more CPU time.

It is just that a Fast Fourier Transform works in linear scale.

Cheers,

    Take