Re: [linux-audio-user] transposing frequency

From: Cesare Marilungo <cesare@email-addr-hidden>
Date: Mon Dec 12 2005 - 00:22:52 EET

Atte André Jensen wrote:

> Hi
>
> Suppose I have an A with a frequency of 440 hz. Which formula should I
> use for transposing x semitones up/down? So which frequency would the
> Bb a half step higher for instance have? What about cents (1/100's of
> half steps)?
>
You know that every note has a frequency which is twice the frequency of
the same note an octave below. You have too go from the A at 440 hz to
the A at 880 hz with 12 equal steps. So, for each semitone you have to
multiply the frequency of the previous note by the twelfth root of two
(approx. 1.059463094).

See:
http://en.wikipedia.org/wiki/Twelfth_root_of_two

c
www.cesaremarilungo.com
Received on Mon Dec 12 04:15:05 2005

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