I was talking with another member here and the topic of the old 70s color organ came up. OK, here's a question- how many people here spaced out to these back in high school? (my hand is raised).
The reason I ask is this- I have a current Lumia projector in the works, and I thought it would be nice to be able to modify it by adding a mode that controls modulation via sound input. I have a modern version of a color organ that blinks LED's, but I have found that this one is more of a peak level meter than a true notch filter that segregates frequency bands. Another thing that I would seek in the ideal circuit is the ability to modulate with intensity, rather than a mere on/off flicker.
There are plently of kits out there, but after much looking, I am not sure any of them possess the specific attributes I require.
I have a toy "spy microphone" that has a sensitive mic and preamp, so I thought that might serve as a starting point. It seems like most of these circuits use what amounts to a speaker crossover to split the incoming sound signal into its respective bands. It shouldn't bee too difficult, but then again I am no EE. If anyone has any suggestions or thoughts, let me know!