Thursday, April 5, 2018

How to input any scale to Korg Triton or Yamaha DX7 mkII


If frequencies in Hz are known one can use a log mathematical relation to convert form equal temperament deviation to cent deference from equal temperament. Then the difference number can be  added to the Triton's equal temperament table for each note.


But a more practical way and fun too is to search on google for an online sinewave generator. Any frequency can be input and played on a computer device . Then each note can be tuned while simultaneously listening to Triton by eliminating beats by ear-brain.  (The nearest to 0Hz we make the beat frequency the more accurate is one frequency to the other. A simple tone should preferably be played on Triton. The ear-brain comparison should be underestimated as it can give the best accuracy of any known device. When you try this you will be amazed how crude 1 cent steps are. When we tune a piano there are an infinite number of angles between 2 positions of a tuning pin, the piano being an analog musical instrument. Our brain can distinguish magnitudes of smaller differences than cents when both notes sound together.


Since octaves are not exact multiples of 2 in frequency to the human ear-brain pitch perception it is advisable to tune one temperament octave and do all other octaves by ear-brain. Just like tuning a piano. Playing the left hand note and while it sounds playing the note one octave up or down to be tuned. Consecutive playing of note should be tried too for the best compromise so that everything sounds correct to ear brain.


Then all other notes can also be tuned accurately by ear-brain comparison of consecutive octaves of the instrument you are tuning. (If you are using Triton consult the manual on how all note scales are edited and stored in memory).


For example with the C#4 you have tuned, you may now tune C#5. Similarly for any other note.


Note:


A complete specification of a tuning temperament should ideally contain specification of the harmonic or overtone frequencies for each note. Overtones have to be slightly higher in frequency than exact multiples of a fundamental frequency. We are humans not robots. Exact multiples sound nearly or a bit out of tune in an annoying way. They give a tense, unresolved disconant character. The nearly out of tune property is very unsatisfactory.


The frequency needs to slightly higher than x2 in order to sound a correct octave to ear brain. So it is too with harmonics or better called overtones of a singke note. The second overtone of a note for example must be slightly higher than x2 for the note to sound pleasing to our brain. This knowledge has been known to mankind for many centuries. For example first we make or construct flue organ pipes to sound correct to our brain and then we tune the organ. other example is the correct amount of inharmonicity of great pianos that evolved in centuries. Those correctly scalled strings dictate the tuning of the correct stretched engineering octaves for the human brain.


What needs to be remembered is that exact x2 in frequency is an engineering or objective octave. Believing that this is a correct subjective ear brain octave is wishful thinking.


We have now the tools or even software to design correct sounding electronic instruments to the human ear brain. The relative fine tuned frequency of each harmonic or overtone is important and will dictate the overall tuning.







References:


Sound and Hearing - Stevens, Warshofsky - Time Life science series


Pleiades tuning - euroelectron


Musical Acoustics - Donald Hall


Piano servicing and tuning and rebuilding - Reblitz


How the Pleiades tuning was derived using Yamaha DX7 ii - euroelectron

(Engineering) Octave Strech - Ernst Terhardt http://euroelectron.blogspot.gr/2015/06/octave-stretch.html



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