help with LED visual equalizer

does anybody know how to build a led visual equalizer?
i was think that it would be 10 leds wide and about 7 high
with colors ranging from green to red
any help would be nice

Ive seen kits for single width ones, but I havent seen much more. I was trying to get a simmalar project going and never did find anything. But Good luck.

This isn't exactly the same it's just 1 row of 10 LEDs, but there is a link to a Winamp plugin that animate the LEDs. linky
I'm think of doing this, it looks really cool.

Is there still interest in this? I have one almost designed and have tested most of the stages

~J

Oh god this is old

Interested a bit still, but I really have no use for it anymore.

I've asked about this in electronics forum some months ago. No one could offer an easy solution.

What you need is LM3914 dot/bar driver that you could wire as 10 LED bar graph in green/red or green/yellow/red but it'd limited to 1 wide. For multiple bars, you'd need to build filters to isolate and pass only specific frequency to one of the multiple LM3914's but this isn't easy as it involves lot of computing to get proper capacitors, inductors, and/or resistors to get the correct frequency range. A DSL filter would be a cheap solution to pass everything from 4KHz and below (voice part for telephone part), and if you find another filter for DSL modem intended to pass 4KHz and up that too. Now day most DSL modem has high pass filter built in.

There is a downside to using a 3914 in that your limited to a linear resistance ladder that is not customizable. If you were to wire it yourself with voltage comparators the voltage scale is completely up to you. You also are going to need an Op-amp running into each 3914, otherwise your results would be poor, as standard audio signals are 1v peak-peak. Id recommend creating two voltage follower configurations to handle both the channels and run those into a voltage sumer config. By using a potentiometer in that op-amp stage you would be able to have variable gain for different audio signals strengths. As far as filtering goes, the calculations are extremely simple. 4GHZ_or_bust suggests inductors as well as capacitors, I however propose filtering with only capacitors and resistors as they are significantly cheaper and in most cases smaller.
~J