Syncing LEDs to audio

I've got this idea and I'm trying to determine if its possible and the best method to do it...

Basically what I want to do is feed an audio signal into my circuit which is low passed at ~150Hz by my subwoofer amp. The circuit will then process the audio and flash an LED (or possibly a strobe light) with a freq. slightly slower than the audio (differing by 1-2Hz). If it works properly, it should look like the subs are just slowly moving in and out (at the 1-2hz difference).

I think I might need to add another LPF in there to cut the freq down to 80Hz or lower since there isnt alot of excursion at the higher freqencies.

It might be easier to do this with a pic...if its even possible.

It may be posible to to analog.Low pass it and add a cap to make a bit of a deay then feed in the LED.

It should also flash to the beat

Here is what I have.

Nice idea, probably not as simple as it first sounds. I'm thinking the only way that could work is a frequency-to-voltage IC connected to a voltage-to-frequency IC and calibrated as you want. A 555 could do the voltage to frequency part using pin 5, albeit rather poorly (with the PWM changing with frequency, and its non-linear response).

A better if more expensive way could involve using chips such as the LM2917 frequency-to-voltage IC and the LM331 voltage-to-frequency.

https://www.electronicpeasant.com/projects/ledlamps/ledcolor.html

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I've decided that this project is alittle too difficult at the moment. Maybe I'll come back to it when/if I take DSP in the spring.

I've got another idea which involves the LEDs that I have installed in the headliner...I have a sound to light circuit that I'm using, but the lighting patterns are kinda random and dont look as good. So, my idea involves enbedding a signal in with the music using some sound editing software that will allow me to tweak how the LEDs light up.

I'd probably use a carrier signal at 15kHz (hopefully the CD player doesnt have a LPF below that?)

What would be the best encoding schemes to use? FSK? PSK? (I wish I would have done better in my communications class). I'll be using a pic16f877A for this project, so I'd need something that is easy to interface to it. Oh and I figure I'd need 3 bits of data (8 possible signals) too.

It is like my suggestions are not what you are looking for. Did you even consider them?

Your suggestions are in the right field, but arn't exactly what jrz is looking for.

I expect the frequency voltage/voltage frequency system could work, or is it likely to be slow responding? I've never actually used the chips. DSP is definately an option, although I'm pretty sure the hardware is expensive?

I once used a bargraph Ic to make the same thing a voltage controlled audio light bar. LM3914
https://www.electro-tech-online.com/custompdfs/2006/05/lm3914.pdf

Hi John,
He doesn't want an audio sound level light bar. He doesn't want a color organ display.
He wants to shine a strobe-light LED on a subwoofer's cone at a slightly different frequency than it is playing, so you can see it slowly moving in and out.

Ya, I wanna make something similar, syncing light to music through the audio jack. There was this tutorial i could not figure out. It involved a TIP31, switch, power, LEDs, and a audio jack. I have pics, but i need someone to tlel me whats wrong.

This sounds like it would look great. If someone gets a circuit up (too complex for me to design, sadly) Id love to try it. Id probably build it right into the enclosure.

I was wondering if multiple leds at slightly different frequencies or phases(in a PWM setup) might work as when the cone moves there would be a shift toward/away from from the LEDs and Moire patterns should be the result.
https://www.mathematik.com/Moire/

Heres one:

http://www.talkingelectronics.com/te_interactive_index.html