Re: [linux-audio-user] transposing frequency

From: Lars Luthman <larsl@email-addr-hidden>
Date: Mon Dec 12 2005 - 00:17:51 EET

On Sun, 2005-12-11 at 22:37 +0100, Atte André Jensen wrote:
> 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)?

To transpose X semitones up, multiply the frequency with 2^(X/12). To
transpose down, just use a negative X. For C cents it should be
2^(C/1200).

Bb above A440 has the frequency 440 * 2^(1/12) = 466.16.

-- 
Lars Luthman
PGP key:     http://www.d.kth.se/~d00-llu/pgp_key.php
Fingerprint: FCA7 C790 19B9 322D EB7A  E1B3 4371 4650 04C7 7E2E

Received on Mon Dec 12 04:15:05 2005

This archive was generated by hypermail 2.1.8 : Mon Dec 12 2005 - 04:15:05 EET