The "Missing Fundamental" demo

[barefoot]

There is a cool psychoacoustical effect which you might be able to use to create the illusion of deeper bass in your mix.

It's called the "missing fundamental effect" and it works this way:

If you hear the harmonics of a tone, but not the fundamental tone itself, your brain will invent the fundamental. You will actually perceive the missing tone an octave below the first harmonic even though it's completely absent on a spectrum analyzer.

Likewise, harmonics enhance the perception of fundamentals which really do exist.


I threw together a quick demonstration.

In Stomper using pure sine waves I created a 30Hz tone, a 60Hz tone, and group of tones of decreasing amplitude which correspond to the harmonics of 30Hz (60, 90, 120, 150 and 180Hz). I didn't put much thought into the amplitudes, they just go roughly like this:

|*
|* 
|*  
|*  
|*   *  
|*   *   * 
|*   *   *   * 
|*   *   *   *   *   *
+----------------------
30  60  90  120 150 180

Attached first is the 30Hz tone to give you a reference

|*
|* 
|*  
|*  
|*   
|*   
|*   
|*   
+----------------------
30  60  90  120 150 180

 

[barefoot]

Now the 60Hz tone.

|
| 
|   
|   
|    *  
|    *    
|    *     
|    *    
+----------------------
30  60  90  120 150 180

 

[barefoot]

Finally the harmonics:

| 
|  
|   
|   
|    *  
|    *   * 
|    *   *   * 
|    *   *   *   *   *
+----------------------
30  60  90  120 150 180

Notice how much deeper this sounds than the 60Hz alone and how you can really almost hear 30Hz in there.

Looking at the waveform gives us an idea why this is. Even though 30Hz is not present, the wave pattern repeats itself at 30Hz. Our brains latch onto this periodicity and perceive it as a distinct tone.

Pretty cool

barefoot

 

[CyanJaguar]

GREAT POST

I was surprised that I could even hear thirty on my ns10ms. I had to turn the volume way up though. I sounded like a kind of thudish sound which I like very much.

The 60 hz tone sounded blahish.

THe tone with harmonics sounded great. As you pointed out, I could hear most of the 30hz THUD in there even though there is not actually any 30 hz present.

I think this is very important in mixing. I had been wondering how to get that deep sound.

peace

 

[tubedude]

123

The Waves Maxxbass plugin does that, removes the bottom end and replaces it with the proper harmonics, therefore giving the impression of bigger, clearer bass on smaller systems. Check it out.