In this article, we will use Absynth to understand what harmonics and waves are all about. Absynth allows you to see both the waveform and its harmonic content. So let’s take a look.
First we will create a sine wave
Now, let’s take a look at its harmonic content
Now, let me help you understand what this thing shows. The yellow lines, above the middle, are the harmonics and their amplitude. Since all instruments use the same tuning (equal temperament tuning), which means that each note is a standard frequency, the harmonic series is always the same. If you remember from the previous article (A few things about audio waveforms and fourier-transform) harmonics are different from each organ. The harmonic series however, is always the same. If f is a frequency of a note in our tuning system, then the harmonic series is 2f, 3f, 4f, etc. What is different, is the amplitude that each harmonic has in each instrument.
In this scenario, we only have the first harmonic, the fundamental, which gives the basic note. The above picture from Absynth, tells us, that should we press a note, like for example C1, we will hear only the fundamental note, and in full amplitude.
The blue lines below the mid-line represent the phase of the harmonic and we will not occupy ourselves for now with this.
So, let’s create some other wave. We will create a square wave.
Now, let’s see its harmonic content.
Now, what we see here, is that in a square wave there are only odd numbered harmonics. That is, the fundamental, the 3rd, the 5th, the 7th, etc. The loudest is the fundamental.
Now let’s play around with the harmonics to see what comes out.
Let’s see what graphic wave function comes out of this
So, in this tutorial we saw, how we can use Absynth’s functions to draw waveforms to understand the relationship between harmonic content and wave. This is a powerful tool (especially for learning),but don’t think that you can really create the waveform you have in mind, in just 5 minutes. The key here is experimentation. You just have to play around to find something you like. The only rule that there is, is that odd harmonics sound harsh, even harmonics sound melodic. Other, than that, the only way to learn is to experiment and learn