Blog Assignments

Are not optional.
It is now 12:08 and several of you have not blogged on the Harmonic series as requested and will not get full points on the assignment. I will explain in depth and give you options on what you may choose to blog on each week, but i expect that you blog prior to the class day so i may read them and we all may comment and communicate with each other during the week.

If you have NOT blogged on the harmonic series YET, please do so but realise everything AFTER this post is essentially LATE and will not receive full credit.

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Fundamental Frequencies and Harmonic Series

Hey all,

I'm Andres, Film and Media Studies major and Mass Communications minor, looking to graduate next fall. I have a pretty sound/music intensive project I'm currently working on and I'm looking forward to this class as it will probably be of great help.

A friend of mine that is music inclined once explained to me the harmonic series, I just didn't realize it was what we were talking about in class. But to get there I should first discuss what I've found on fundamental frequency. In plainest terms, the fundamental frequency is the lowest frequency at which an object vibrates freely. This is one of the definitions I found, but mostly applies to just physics. In music however, this is incomplete. A fundamental frequency is the lowest frequency of a periodic waveform. If I'm correct, periodic waveforms in sound are sustained sounds without varying pitch, although their frequency may be low enough that you can hear the variations in wavelength. Because the wave is periodic, meaning it repeats exactly the same, one period alone of the wave serves to describe the entire wave. This period is thus known as the fundamental period, and the lowest frequency for which this smooth repetition remains true is the fundamental frequency. The fundamental frequency is also the first harmonic.

The harmonic series then is the series of sounds produced when the frequency is increased by adding the initial frequency repeatedly. For example if the frequency of the fundamental is 50 Hz, the second harmonic would be 100 Hz, the third 150 Hz, etc. The harmonic series is related by whole number ratios, and like stated before, have periodic waveforms. When these are played in conjunction to each other, they sound very smooth and pleasant, whereas other notes whose frequency does not fall in the harmonic frequency, have irregular and/or non-repeating wavelengths, and thus don't sound nearly as pleasant. This is because all the tones on a harmonic series are related by whole number ratios; same wave with increased frequency by two times, three times, four times, etc.

I have heard this being played in a piano, going up a harmonic series from C to C to G... etc, and with dissonant keys not from the series thrown in to clarify the point.

On another note I found this video on YouTube about an iPod application that may help on the understanding of periodic waves.

Harmonic series.. so essentially every sound has a frequency which is a wavelength, the higher the note the shorter the wavelength and the shorter the frequency. Each instrument creates a different sound due to its structure which creates a different wavelength and frequency even though they all may be hitting the same middle c.

A harmonic series can have any note as its fundamental wavelength. So there are many different harmonic series but the relationship between frequencies in the series are the same. So essentially say you have a trumpet on a middle C, that creates a fundamental wavelength...lets call it the "Fundamental note"..or the "Fundamental Harmonic"... the second harmonic always has exactly half the wavelength (twice the freq) of the fundamental; the third harmonic always has exactly a third of the wavelength (3 times the freq) of the fundamental.. etc..

Thats essentially it. From what i understand

-Tim

Interesting Stuff

Hey guys.  Just thought you all might be interested in seeing this... It's a pretty cool little project, I think.  It's called Tanguy Ukulele Orchestra, and it is this guy who put together little clips of himself humming and what not.  They actually come together to be something tangible.  I was thinking about doing something like this for one of the projects.  Let me know what you all think.

http://www.miniclash.com/tuo/

Introduction

Greetings,

I just wanted to introduce myself to the class. My name is Matthew Carroll and I am a Masters student with Digital Worlds. I have bachelors degrees in both Computer Science and Mathematics. I'm with Digital Worlds to help gain some proficiency in creative media to compliment my software development skills.

When it comes to audio design I have zero experience. I played with Fruity Loops and Rebirth about 10 years ago but gave up very quickly. However, I do love techno music and hope that we can pick up some skills in that area this semester.

I read a bit about harmonics as requested but it seems the amount of it I understand has already been posted on this blog. There is one element, though, that might benefit from some clarification. We keep hearing this term "fundamental" and it wasn't clear to me what "fundamental" was. One finds that harmonics are multiples of this "fundamental" frequency - and a "harmonic series" is based on multiples of the fundamental frequency. In examples it seemed that the fundamental frequency was taken from nowhere - just some hypothetical number.

So I'd like to clarify how one arrives at a fundamental frequency. Consider a string. If you hold that string taught at both ends and pluck it, that string will vibrate in and out at some frequency - this frequency cannot be changed no matter how hard you pluck because its based on the length and type of the string. The longer the string, the more distance in its vibration, the lower its frequency. The shorter the string, the less distance in its vibration, the higher its frequency. Thus this "fundamental frequency" is that frequency at which a string will vibrate when held taught at both ends. However, this concept extends to other media as well - for example air in a cylinder has this concept of a fundamental frequency, and though I don't remember this for sure, my guess is that metal rods also have this fundamental vibration frequency (tuning forks?).

I hope that helps someone.

Matt

Harmonics

I did a little reading on "harmonics" and the "harmonic series". I play the guitar, so this is good stuff for string instrument players, especially, to understand. Basically, I am understanding that most of the sounds we hear are complex. A sound oscillates, or vibrates at multiple frequencies for even one note. If the frequencies are integers of a fundamental frequency, they produce sounds that are harmonics of each other.

An integer of something means simply that if the fundamental frequency is 25Hz, that 2 x 25Hz, 3 x 25Hz and so on, would produce the harmonics for that particular wave. Conversely, if a wave is oscillating at partials/frequencies that are not integers of each other, the sound is referred to as inharmonic and not so pleasing to the novice ear.

The way that our ear discerns the different styles of sound or timbre (ie: the difference between the flute and the clarinet playing the same note), is the result of the relative strengths of each individual frequency making up the sound.

SPRING 2011

Hello and welcome to Sping 2011 ADDP
SO far we did the intro to the class and covered what we will be doing and i gave a basic outline of my expectations, history and qualifications for this course. I hope you all are as excited as i am about this class, we will have a nice intimate class and i hope to get to know you all and share some great design ideas, technologies and interests inside this semester.

SO far i have asked that you
DOWNLOAD AUDACITY and play with it a bit if you can
http://audacity.sourceforge.net/download

Join Freesound
http://www.freesound.org

and create a soundcloud account too
http://soundcloud.com

just so we can find, edit and upload our work as well as joining blogger!

see you all tomorrow when we start tweaking!