Im new need help cause im lost!!

[ll y3m1t ll]

Hi im new to this forum so please dont eat me if this is in the wrong section. I have recently just put LED's in my xbox controller ports not hard i know but i wanted to start off with something easy then i was thinking of making lights flash with music and this is an idea i had. If i had a power supply going to the LED's with a resistor but before it got to the negavtive rail put a transistor in it so when i put a positive music wire into it, it would beat with the music?? Im really don't know if that made sense to anyone at all but it's an idea i had and i just wanted to ask the pro's Thanks in advance

UPDATE: For those who don't have a clue what im on about heres a picture of what im thinking of doing
**broken link removed**
I don't know what values to put in for resistors and such. Also forgot to add LED resistor.
Thanks

 

[audioguru]

The base of a trasistor is its input. A current-limiting resistor must be used in series with the base so that the music source and the transistor don't blow up. Then if the music is more than 0.7V the transistor will turn on briefly for half the music. The other half of the music will blow up the transistor if a reverse diode isn't across its base-emitter. A resistor should also be across the base-emitter to turn off the transistor when it shouldn't be turned on.

So a transistor, three resistors, a diode and an LED will work, but poorly.

I have a circuit that quickly charges a capacitor to the peak level of music and the capacitor holds the peak for a few moments that are long enough for your eyes to see. The LM386 can drive up to 18 LEDs each one with its own current-limiting resistor.
I have a Veroboard layout for it if you want.

 

[ll y3m1t ll]

ok so scrap my idea and follow the circuit u gave me. So if i connect the music source upto the circuit it will flash with the music. I don't know what voltage it is running through the music i just know that that speakers can handle 50 watts RMS which i never go past the loudest they woulld be is 50 watts if that helps any to this.

 

[audioguru]

I don't know how much or how little is the output power of an X-box. You can connect 50W speakers to a 1/2W amplifier and the output is only 1/2W, not 50W. So don't turn up the pot too high in my circuit or the LM386 will fry. Maybe you should add a 10k resistor in series with the input to the pot for safety.
Here is the Veroboard layout for the circuit.

 

[ll y3m1t ll]

right kk thanks alot, soory about all the questions only 16 years old and new to all this. All i no is that the display on the stereo shows up what wattage it is outputtingand i never put it past 50 watts. Also is this what that diagram is for. **broken link removed** thanks

 

[ll y3m1t ll]

ok thanks for that so when i input my music to this is shud pulse with the music especially like dance and stuf since im into that kinda stuff lol and i never put my speakers past 50 watt i have a small display on my stereo that tells me the output. so is this a veroboard **broken link removed**

 

[audioguru]

The Maplin stripboard is fine for a circuit board.

The circuit is designed for a low input level so connect a 100k resistor in series with the input pot to reduce your 50W down to a safe level.