How to make a clock to feed a 4017 with the bass of a music.

Thread Starter

MatheusLPS

Joined Jul 16, 2011
34
So, I am trying to do a simple bass detector to "convert" it to a clock that I will put into a 4017 decade counter to count :)p) the leds on every bass note.

But it is not working like I want.

Sometimes the 4017 counts more than "one note" on the bass and the leds on the outputs lights up randomily....

I build this circuit:

http://img.photobucket.com/albums/v222/ahhh/Eletronica/vout.jpg

Is it correct?

Just to ilustrate, let me show you some screenshot of my simulator program:

Lets get a music of example : Black Eyed Peas - The Time [The Dirty Bit] (Main)

If you get this music, and play it from 40 seconds to 80 seconds, you will ear some mid and high notes from 40secs to 60secs and from 60 to 80 secs, there bass notes.....

So I took this music and put into my simulator program, the Proteus from Labcenter Electronics and configured the audio input like this:

http://img.photobucket.com/albums/v222/ahhh/Eletronica/audio_in.png


I put the audio into my simple RC circuit:

http://img.photobucket.com/albums/v222/ahhh/circuit_LP.png

and got this:

http://img.photobucket.com/albums/v222/ahhh/Eletronica/out-1.jpg

The green one is the audio in and the red one is the out after the filter.

Look and you wil se that from 40 to 60 sec most of the audio is cut beacuse I have a lower-pass filter. From 60 to 80 most of the song pass beacause there is a lot of bass on that part.

The filter works, if on my original ciruit, above, I put the out signal into a trasistor base and on the collector I put a simple LED with a current limiting resistor, the led blinks only with the bass notes.

So I thought that if I put this "pulsing" signal from the collector into a 4017 this would be a clock.... but like I said, do not work very well....

PS: Sorry my english mistakes, not my mother language.

bye
 

praondevou

Joined Jul 9, 2011
2,942
That's not an easy task. Please google "bass beat led" or "bass beat detector". Many people tried it and succeeded to some degree.

But the main problem is that the beat is not always easily recognizable/distinguishable for an electronic circuit depending on the music you play.

I also think the low-pass has to have a steeper slope not the one from a simple RC. Once extracted it should pass through a schmitt trigger circuit, you don't want to feed the 4017 with some random noise.

If you want a really 100% working circuit, it's not gonna be done with 3 or 4 components, sorry. :)
 

Wendy

Joined Mar 24, 2008
23,429
You are going to get pretty much the same answers you got at Electrotech (most of us hang out in both locations). A simple low pass filter followed by a peak detector (think AM demodulator circuit).
 

Audioguru

Joined Dec 20, 2007
11,248
You need a better lowpass filter (a multiple-order active one) because your simple one also passes voice frequencies up to 1kHz and higher.
 
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