Wiring lights to speakers

[captain_insano]

Hello all, I guess this is my introduction as well as a question. My name is Sean I go to SUNY Delhi for HVAC so i have some electrical experience. Now my question is, I have a a sony stereo system in my room at home, its not anything fancy, just some run of the mill stereo you buy in Target thats always on sail, about 530 watts of RAW SOUND POWAHH. Anyway, it has these holes for air to flow through to help keep the drivers and speakers cool. Actually getting to my question now lol, i want to wire in some sort of LED or light from the speaker wire coming off of the control unit to have the lights blink with the beat of the music. can i just buy two LED's that will handle the load o do i have to have like a small pc board to power them so i dont burn them out?

 

[Ken_McE]

What is the power that actually gets into the speaker? What voltage, how many watts?

 

[captain_insano]

What is the power that actually gets into the speaker? What voltage, how many watts?

i figured i would have to get that before selecting my LED. but besides the power question can i just wire an LED into the circuit or would i have to get a PC board and driver and all that?

 

[DonShock]

There are some pretty cheap pre-made systems intended for lighting up computer cases.

$8 Blue-Green-Red sound activated CCFL
$6 Blue only sound activated CCFL

 

[Magnumpy]

I have a set of transparent speakers with LEDs, here is a picture of the subwoofer:

http://i36.photobucket.com/albums/e16/josiahsuarez/DSC01319.jpg

as you can (sort of) see the LEDs are mounted on a PCB with some resistors and capacitors. but you could always try just running an LED straight in line with the speaker wire and see how it goes! you might have to really crank the volume before you get any light

 

[mahoney]

What goes to speakers is pretty much AC at varying frequencies, and can easily be at voltages high enough to fry an LED. You are going to need a circuit to protect the LEDs, but there's probably someone out there on the net who's already figured this out and posted a design.

 

[JohnR66]

I had to see how this would work, so I hooked up a couple LEDs to a small chip amp. This small amp makes 2 watts into a 4 ohm load before clipping with a 9 volt supply.

It works although the blue LED took more signal before it would light due to its higher rated forward voltage.

LEDs should be connected reverse parallel in series with a limiting resistor. In your case, use a 1K Ohm resistor if you like to crank it up. Good quality LEDs, such as the Cree brand will be bright. Avoid the cheap LEDs sold at places like that certain auction site.