Color organ/Audio visualizer with AGC.

[inkoverflow]

So I'm in the process of making a color organ from an Arduino and a ws2812b led strip. However I want the visualization to be independent of the volume level, through other forums I have found out that an automatic gain control is what I need however I want to check with others if this seems like a good idea and if this ic called AN5285K i found through eBay is a good alternative.

 

[Audioguru]

I cannot understand Panasonic's Jinglish. The AN5285 seems to compress loud signals so they are not so loud.
If you use it on a color organ then the LEDs will either be mostly on all the time or be off most of the time.
A color organ is supposed to show the dynamics of frequency bands.

 

[inkoverflow]

Okay maybe this ic isn't best fitted for this application however the idea of using an agc to get the visualization independent of the volume seems like a good idea?

 

[BradtheRad]

One of my early projects was an inexpensive color organ kit at Lafayette (or Radio Shack). It had three audio bands, each turned on by a triac (scr?). The different-colored bulbs were on or off. No variations of brightness. I thought it didn't look right. I thought it should create varying levels of brightness, based on sound intensity of bass/mid/treble. Then it would look more natural.

 

[chuckey]

It is very important that the brightness of the LEDs match the volume of the music. In the case of the triac based light show, some current must flow through the bulbs in the absence of music so even the smallest amount of music will brighten the bulbs slightly. The same should be done with LEDs. Put a suitable (1.6V?) voltage bias on them in the absence of music.
Frank

 

[inkoverflow]

Okay to clarify the sound signal is still supposed to affect the led's not neccecairly by brightness I want that to be the same as a normal color organ. The trouble is I don't want the reactiveness of the leds to be more or less when i turn the volume up/down, to get the correct visual effects as it is now i need to set the volume at a specific level.

 

[Audioguru]

Recorded music and voices are already compressed with a dynamic range of maybe only 30dB. If you compress it even more so that the LEDs still light when you turn the volume up or down then you will not have any dynamics. You need an extra pot on the volume control that can adjust the gain of the color organ.

 

[Externet]

I would try a volume control IC. Feeding its control input with a sample of rectified audio input.

 

[Audioguru]

I would try a volume control IC. Feeding its control input with a sample of rectified audio input.

Then like the compressor in a radio or TV station, when there is a sudden loud sound then normal level following sounds are cut to a very low level then their loudness slowly comes back up to normal.