Hello everybody

Since yesterday I discovered new backgrouds for anna-vu, I'm running it all day. And I've noticed a strange behaviour: does it only measure the low frequencies? It seems not to 'hear' middles and highs, and only moves with deep bass...
And, does equalization affect the anna-vu ear?

Ok, maybe there is a FAQ entry for this, but I couldn't find it...

Thanks again!

Miguel.

...waiting for radio kit #74...

Equalization does not affect the visuals. Neither does Voladj, as far as I know.

Regarding the high and low frequencies: Take a look at a spectrum analysis of a given song sometime. You'll see how high frequency sounds seem louder to your ear than low frequency sounds at the same DB deflection.

Also, I wouldn't find it surprising that the visuals respond to low frequencies. Most of the visuals have aspects that want to change to the beat, and a simple way of detecting the beat of a song is to look at pulses in the low frequencies.

It's quite likely than the VU meters respond in this way as the rest of the visuals do.

Yes, it could be that way.
I've tried with some test tunes, recorded to tune subwoofers, and the results are that anna-vu only responds to low frequencies...
One of the tests goes from 20 Hz to 20 khz in an oscilaing wave, always at the same Db level. With other visual (spectrolog128) I can see the line going from left to right always at the same level, crossing the screen.
With this tune, at the beginning (low freq.) the gauges of anna-vu moves near 0 Db mark, then they fade out as the freq. increases.
It seems to use the 'beat detection' system as you said.
My old-style pioneer cassette deck, with analogue vu-meters, seems to listen to all the audible range... maybe anna-vu uses a peakmeter instead of the traditional system?
Even being that not so real, I like how fast and responsive it is.

Thanks:

Miguel.
Spain.

Desesperatly waiting for a tuner module #74...

I suspect the algorithm may be looking at the amplitude of the signal, and not the energy content contained within. According to physics, the energy contained in a waveform is proportional to both amplitude and frequency. In other words, you can increase the energy (and perceived loudness) by increasing either frequency or amplitude.

A consequence of this is that if you compare the waveforms for a high-frequency and low-frequency signal which sound equally loud, the high frequency waveform will have a much smaller amplitude. If you combine the two together, the low frequency waveform will dominate the overall raw shape and height of the waveform. When you extract the spectral response curve from material, you must progressively scale up the upper frequency values in software to account for this effect.

- Chris