Under Seat Music Synced Lights for Car (Updated)




About: I am just your average high school football team captain who happens to be a total nerd and loves electronics and making things... If only my brain were as big as my biceps....
This is an updated version of My under seat music LED lights. I originally used regular LEDs and the installation was not very clean. This version uses LED strips and the components are barely visible. The lights are very bright and installation is not very difficult. Please vote for me in the car audio challenge.

Parts required:

Car Adapter
TIP 31c transistor
LED Strip  (also order 3 extra connectors)
Audio splitter


Soldering Iron
Velcro tape
Wire stipper

Scroll through pictures for steps for preparation.

This Video will show you how to install them and what they look like.


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    12 Discussions


    5 years ago on Introduction

    hey just wanted to say this is a good instructable. I did the same thing to my van. I used blue LEDs cause that's the theme color inside. it worked out great thanks to your instructable.

    your lights aren't very accurate to the beat so what i did so solve this problem on my home stereo (ps i have no lights for car yet) but what i did is get a poetintiometer or rheostat they are the same thing get like a 1000 ohm one and hook it only to the crap wait u cant do that never mind u can only do it if u have a speaker that is going to be at a differnt volume or u dont want to hear much

    1 reply

    wait u can neermind ok so from your spliter thing u put poetintio on positive and it adjusts
    the point at which the transistor turns on the lights ether making it more or less senitive
    and this way u need no extra speaker u will hae to adjust the dial on the poetinio on differnt song depending if some are just natualy louder which means too much flash not accurate or u adjust when u change your volume


    7 years ago on Introduction

    Just so you know, in IL it is illegal to have any lights under your car when you drive... So don't mount these under your car if your in IL. (Also it could be a distraction while driving... So be careful.)

    7 replies

    Reply 7 years ago on Introduction

    Thanks for the heads up! But the lights go underneath the back seat of my truck not underneath the truck itself. Since they are in the back seat they shouldn't be too much of a distraction to the driver. It was nice of you to be concerned about my safety though!! Thanks!


    Reply 7 years ago on Introduction

    No problem! I was more or less saying that for anyone who might duplicate this... It wouldn't be hard to modify these so that they go under the car, and if it's illegal in IL, then I'm pretty sure it would be illegal in a few other places as well.

    The safety would probably be more of a concern for me than for you... I have a background in intelligent lighting, so I tend to get distracted by lights very easily. ;)


    Reply 6 years ago on Introduction

    IL is known for being quite restrictive. I don't know this for a fact but it could very well be illegal in IL only, again I don't know that as a fact but it wouldn't surprise me one bit.



    Reply 7 years ago on Introduction

    i know where i live its illegal to have white, orange or red lights underneath the car, because those colors resemble the indicator lights and whatnot on a vehicle.


    Reply 7 years ago on Introduction

    No problem! (I probably could have been a little clearer, so it's not your fault.)

    Keep up the good work!