Microphone output driving PWM LED loudness indicator

[ccurtis]

I got it to where I am quite satisfied now. Ear hears voltage, S, as S^0.3. Eye sees voltage ,S, as S^0.5. Take the square root of the voltage, S^0.5, and call it S'. Eye sees S' as S'^0.5=S^0.25 which is close to S^0.3, which is what the ear hears. Experiment with that approach looks quite right.

 

[Tony Stewart]

Your eyes and ears might be able to comfortably detect 100 dB or more when young but you don't have this dynamic range on a TV so you certainly won't need more than that. If you want it adaptable to any environment 30dB range is plenty. with fast-attack slow-decay quasi-peak detecting AGC to normalize it, if you are too lazy to adjust the sensitivity,

I remember a Manitoba musician had a semitrailer with the inside walls having thousands of tiny coloured lights arranged in an array and driven by 1/3 octave stereo graphic equalizer in 3dB steps. ... playing his music of course. But I really liked the quadraphonic display in the EE lounge at U of Mb in early '70s that Advance Electronics provided. They modified a TV using RGB colors with no raster scan. Instead the yoke was rotated 45 degrees and had a radar plot of 3 bands from 4 sources starting from a dot in the center. Lissajou had nothing to compare.