Amplitude Modulation Synthesis

I recently got my technician license for operating HAM radios, so I decided to blog about amplitude modulation. Amplitude modulation consists of two oscillators, a carrier and a modulator. From our previous exercises, we learned that an oscillator generates a tone. However in amplitude modulation, the carrier could also be another type of signal, such as an instrument or vocal input.

The modulator oscillator controls the gain of the carrier signal. Below is a video created by a radio teacher to help visualize this concept. It helped me understand how data can travel on a specific signal.

Additive Synthesis, Tremolo, Ring Modulation

Additive synthesis is simply combining two or more signals into a single waveform. When two waves are added together, the new waveform contains characteristics of all the signals combined to make it. Amplitude modulation synthesis is where the gain of one signal is modulated by the gain of another signal. Tremolo is a form of AMS where the gain of an audio signal is changed at a slow rate often at a frequency below the range of hearing (20 Hz). It is often used as an effect for organs or electric guitar. Ring modulation is where one audio signal is modulated with another audio signal, which has both positive and negative values. It is often used to create alien voices or distort an analog signal with a digital one.

Weekend HW

 pick 2 of the scales and replicate them in PD
http://www.kylegann.com/tuning.html



Do the Simple Synth tutorial located on the left column beneath the audio tutorials section 

http://en.flossmanuals.net/pure-data/

start these tutorials
http://en.flossmanuals.net/pure-data/

Just Intonation

In music, notes are defined by the their frequency, and their relationships to other frequencies. Since our ears are capable of recognizing frequencies in the 20 to 20000 Hz range with great accuracy, we rely on mathematical observations when devising a musical scale out of different frequencies. Two main types of assigning notes to frequencies are just intonation and equal temperament. In just intonation, the frequencies that define notes are related by ratios of small whole numbers. On the other hand, equal temperament defines all notes as multiples of the same basic interval, so that the distance between each frequency is the same for all.

Here is an example sourced from Wikipedia, it plays a pair of major chords with the first in each sequence tuned in equal temperament, with the second tuned in just intonation.

http://upload.wikimedia.org/wikipedia/en/9/99/Just_vs_equal.ogg

Just intonation

Just intonation is a type very precise of musical tuning. Notes in a series are spaced apart by ratios of small whole numbers multiplied by the frequency of the Fundamental note (aka first harmonic). This differs from equal temperament because the intervals between each note are not constant. Musicians who rely on close harmonies prefer to use just intonation because the sound is much more stable. Perhaps computers and electronic make it easier to achieve these sounds, when traditional instruments are not always calibrated to be so precise.

 

 Sources: 

Harmonic Series. (n.d.). Retrieved from http://www.scottopus.org/topicharmonicseriesSS.htm

Just Intonation. (n.d.). Retrieved from http://en.wikipedia.org/wiki/Just_intonation

Just Intonation vs. Equal Temperament. (2009). Retrieved from http://www.youtube.com/watch?v=BhZpvGSPx6w&feature=youtube_gdata_player

Creating a new window for design...

That's been always my slogan, and how I see Digital and Graphic design. My name is Juan Carlos Tafur Mejia, and now I'm doing my MA in Digital Arts & Sciences in The Digital Worlds Institute. I feel blessed to be part of this new experience and goal because my best interest is to become a professional 3D designer to create 3D modeling and animations combined with visual effects for movies, films or commercial publicity. I graduated in 2008 from the college of Liberal Arts and Sciences at UF, and after been working as a freelance designer for 4 years and now at UF as a web designer, I'm back to school to combine my graphic and web design and development skills with everything that this new program has to offer. Everyone can visit my two websites to see my work at www.digi-graphical.com and www.jcdesignideas.com.