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oscillator, test tone, and sine waves, oh my!

I hear terms like oscillator, test tone, sine waves, pink or white waves. I know that they are gotta have tools and knowledge for serious recording people. Can anyone explain to me in laymen terms, what they do and how I can use an oscillator to improve my recording? I have Emu1212m soundcard and it has DSP which has some test-tone generating function.




RemyRAD Tue, 05/09/2006 - 18:28
Definitions 101

Oscillator: something you put batteries in for personal gratification

Test tone: "Don't talk to me that way young man!"

Sinewaves: Pedro sez see you at South of the border in 42 miles

Pink noise: Senator Barney Frank

White noise: Rev. Jerry Falwell

An oscillator is something that generally (at least at this forum) refers to an audio test device but really pertains to anything that creates electromagnetic waves from direct current to gamma waves, you know? Beyond light?

We use certain frequencies to analyze our audio equipment that relates to our human hearing and so we use test tones created from 20-20kHz (for the most part), as a steady tone or as a sweep from low to high, in conjunction with our analyzers, oscilloscope's, volt meters, etc..

Pink and white noise are also related to brown noise. No shit! It's true! Those three types of noise are three different types of " static", in that white noise relates to more high-frequency weighted noise while pink noise sounds more like a rain shower and brown noise sounds like the rumble of your automobile engine under your feet.

How can you use an oscillator to improve your recording? Hopefully you will not have to. For the most part, most of this digital stuff all utilizes a finite amount of popular chips that have fairly flat frequency responses. In the days of analog tape, differences in tape formulations and head construction required us to tune our recorders from one session to the next and more often than we tuned up our cars. Of course the late great Robert Moog had a different idea on how to use oscillators that changed the world.

Definitions R US
Ms. Remy Ann David

pmolsonmus Wed, 05/10/2006 - 11:54
While I rarely disagree with Remy and I don't really this time. A bit of clarification may be in order. I'm sure Remy knows this but a number of readers may not.

Basically an oscillator uses electricity to create a wave. Amplitude (louds and softs) and Frequency (high/low pitches) can be altered and using a variety of eq and timing effects can be made to sound like almost anything. (e.g - your basic 1970's analog synth to the most up-to-date digital tone generator) The core tone is a sine wave which can then be altered to create triangle, sawtooth and square waves.
(sawtooth = all even harmonics 180 degrees out of phase, triangle all odd 180 out of phase, square all odd in phase.

White noise is random occurence of all frequencies so that the sound energy in every equal bandwidth is the same. (e.g same sound energy between 100Hz and 200 Hz as 1000Hz and 1100Hz) Sounds higher and hissier (no offense Remy :D )

Pink Noise is random occurences of all frequencies so that every OCTAVE possesses equal sound energy. (e.g 100Hz and 200Hz is the same as 1000Hz and 2000Hz)

Get a book and start reading. Running noise through a system with a spectrum analyzer can help you determine which frequencies are emphasized in your listening environment and can help you to determine acoustic treatment that can minimize the effects of reflections and standing waves.

Good Luck

pmolsonmus Fri, 05/12/2006 - 11:49
Fourier's Theorem states that "any periodic vibration, no matter how complex, is equal to the sum of a series of simple vibrations (called components, whose frequencies are harmonically related"

A sawtooth waverform is the sum of ALL harmonics, each with an amplitude of 1/n times the amplitude of the fundamental (where n is the # of the harmonic) AND with all EVEN numbered harmonics shifted 180 deg. out of phase.

I could do the same for triangle and square, but that's not the issue.

I was trying to summarize and point out the major distinction between the waves in a way that a general reader could use and remember. The poster wasn't asking for the theorem.