LEDs Sync to Music (with Pics of My Awesome Computer Case Mod)

 I'm finishing up my computer table i've been working on and one of the final touches is making LEDs sync to the speakers.  I have some pics of my computer too.  This project took me about 15 minutes and was free because i had the parts laying around.  

 Items:

-TIP31 transistor

-4 LEDs or 12v led strips

-wire

-on/off switch

-3.5mm jacks (1 male and 1 female)

-solder

Tools:

-soldering iron

-wire strippers/cutters

 Here is the circuit i used.  For the 12v power supply i found a spare molex connector from the computer power supply and cut it. I used a multi meter to find which 2 was the positive and negative.  (for me the yellow was positive and the black wire beside it was negative).  Be careful when doing this and make sure the computer is off to prevent the risk of electric shock. (im not responsible if you get shocked or hurt).   If you have any questions just comment below.

Plug in the computer speakers into the audio jack and plug in the male audio jack from the circuit into where you would normally plug in the speakers.   Mount the LEDs and switch.  Now turn it on and put some music on.  

 I'm going to finish it when i get some glass, i just have to put a back and top on it and put a piece of glass over the screen. please rate and comment. (: