Sub Bass - Wave Shaping
2001-08-14

You might find this usefull you might not.

Its fairly simple, just use a pulse waveform with a very narow pulse width, around 10% for example.

The reason for this is that the standard wave forms you have availible in every synth are

Square -- The harmonics decrease in volume by 6dbs an octave 

Saw -- The harmonics decrease in volume by 6dbs an octave 

Triangle --- The harmonics decrease in volume by 12dbs an octave 

Pulse --- which at 50% pulsewidth is the same a the square wave. But as the pulse width is reduced the harmonic rolloff is also reduced. So the closer you get to 0% pulse width the closer you get to a harmonic series with equal volume for each harmonic in the waveform. 

The reason that this is good for sub bass is that if the fundamental frequency goes below the lowest bass the speakers can reproduce then the next harmonic in the waveform is almost as loud as the previous one so there will be a less obvious drop in volume than if you use a square, saw or the worst triangle. 

You can demonstrate this by setting up a patch with each of these waveforms and playing them down bellow the bass response of your speakers. A sine wave will die realy quick. Next comes the triangle wave which also dies realy quick. Square and saw arnt so bad. But by far the best is the narrow pulse waveform.

Obviously the narow pulse will need to be lowpass filtered to get rid of most of the hight frequencys and make it sound more like bass. 

chris
