Led strips syncing to bass

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Thread Starter


Joined Jun 6, 2014
Hey guys, I have in my car a aftermarket audio system (4 speakers with a 600w kenwood KAC-8405 and 2 12" subwoofers 1200w each with a pyle 2220-pa 2400w amplifier) and 9 led strips 12v (5 blue strips and 4 RGB strips). I want to make a circuit using TIP31 transistor to make the blue one sync to the base (abviously from the subs). I once made a circuit that I saw on a web site, it worked so great went the music input was from my computer speakers (with a auxiliary plug) and when I tried on my car system, the 2 20amp fuses from the subs amplifier blew off... What do you guys suggest?


Joined Sep 17, 2013
when I tried on my car system, the 2 20amp fuses from the subs amplifier blew off... What do you guys suggest?
Since we have no clues (e.g. a schematic) as to what your circuit consisted of it's difficult to advise, other than to say 'don't use that circuit' :)


Joined Jan 10, 2012
If the circuit worked with your computer, then something went wrong when you tried to connect it to your car system. Did the circuit survive? Can you still use it with your computer? How did you connect it to your stereo? Could you have mixed up the wires? We all do it.


Joined Oct 26, 2011
A bit of a rethink is needed here as the amplifier you were trying to connect to definitely will not like its output connected to anything other than what it is designed for due to the design of the op stage....maybe a better way would have been to use a stand alone led driver ..... I posted such a schematic a while back-chances are the fuses blew because you grounded the op stage .....


Joined Aug 26, 2012
It is important to note power. While I have no practical experience with audio and lights and I am interested in it and hope some day to build an awesome sound system.

There are three or so stages of power. You have your input (Ipod, phone etc), your stereo output and your amplifier output. If you hook the leds to the amplifier output (which I'm assuming you did) then you are putting 300+W into LEDs, hence why they blue (pun intended) up. I would suggest, having a steady level for your lights to run off with, perhaps with a pot to adjust slightly if needed. Then you can have your lights flash the same way no matter how loud you have the music. For this I would suggest using a splitter cable (assuming you're using an ipod or phone of some sort) have one end go to the stereo and the other to your light configuration. You can then use transistors to up the power.

Lots of people just hook up some LEDs to their speakers and think they are some electrical-audio geniuses... until they blow.

What would be cool is if you then used the RGB to work with all three mids highs and lows. Red could be High, green mid, and then blue lows.

P.S. I have never done anything like this before, this is just pure hypothetical speculation based on minimal previous experience.


Joined Jan 10, 2012
You don't put 300W into LED's when you connect to your amplifier ( at least you hope you don't ) The amp might be pushing 300W, but that doesn't mean the LED's are absorbing it. For example, if you're delivering 300W into 8 ohms, that means you're RMS voltage is Vrms = sqrt(300*8) =~48V. You only want 20mA or so in your LED's, you might connect a 2.7k series resistor. Now, your LED+resistor is only absorbing 850mW. If you do it right, you absorb less.


Joined Aug 26, 2012
You're right , but it sounds like the OP did not have right resistor matching. And also I think lights hooked directly to the sub still would only have one sweet spot as far as music volume.


Joined Apr 5, 2008

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