Sampling, Additive Synthesis, and a Man Named Fourier

            What is the difference between a sampler and a synthesizer? Sometimes depending on the sampler, not much. A sampler instead of having an oscillator to generate its signal has previously recorded sounds that are used, and in some cases modified just like a synthesizer. So some samplers are in fact synthesizers.

            My next question that I have for myself is, if synthesizers can create whatever sound you want it to, why do you need samplers? The answer, “Myself”, is because while synthesizers can create a vast number of sounds, they do have their limitations. Take Additive Synthesis for example. With Additive Synthesis, you can create any sound you want by adding sinusoidal waveforms on top of each other to create a lifelike sound such as a piano. The difficulty lies in the fact that complex waveforms such as our voices, a piano, or a bird singing, have an infinite number of harmonics, or for this examples sake, sinusoidal waveforms.  

On a side note, it was Joseph Fourier that figured out that all complex waveforms could be broken down into sinusoidal waveforms. Science is fun.

This representation of additive synthesis shows
just 3 waveforms. Now just imagine adding 100
more to get closer to an accurate representation.
And suddenly the redundancy of the matter
sets in.

            A complex waveform, such as a note on a piano, has what is called the fundamental, or the lowest frequency heard that acts as the base for all the rest. On top of that fundamental, there are harmonics, or partials (harmonics are whole-number multiples of the fundamental, while partials are any frequency within the sound’s spectrum) that stack up and create the unique sound. By adding all these partials together and varying the amplitude of each we can create a fairly close representation of the sound.

            Additive synthesis has its limitations, and that is it can be costly to keep buying oscillators, envelope generators, and amplifiers for each sinusoidal waveform. New technology such as virtual instruments make the stacking of a large number of waveforms possible, and only are limited by your computer’s processor, but it takes time and it is not the most enjoyable form of synthesis (who knows, you can be weird and like it, I wont judge you…). Each time you stack the sinusoidal waveforms and get an accurate representation of the sound, you just created one pitch; now if you want to mimic an entire piano, you have to do it for each individual note (I’ll see you in a few years when your done).

            That is where samplers come into play. Samplers allow you to take a recording of a sound, such as a piano note, and play it. By doing this, instead of having to go buy an expensive piano, you can get a fairly accurate representation of just about any piano. While the more expensive sampling instruments do cost you a hefty sum of money, it is nowhere near as much as that grand piano you just sampled costs.

            Piano sounds are just one option, samplers allow you to load any sound you want into them. They give the performer access to sounds and instruments that they 1) would otherwise not be able to play or have access to and 2) not be able to or want to purchase. A world of possibility lies within the world of synthesis and sampling, you just have to take the time to find it (hopefully not with additive though, but again, I’m not judging you…).

A caption depicting
the first 6 harmonics of
a sound.

A spectrum analyzer depicting the frequency content of a sound. 

...My mistake in "Player Piano" was my failure as a futurist. I did not foresee transistors, and so imagined that super computers would have to be huge, with bulky vacuum tubes taking up a lot of space. -Kurt Vonnegut in "Letters"