From:  Jens M Andreasen
To:  mailto:linux-audio-dev@lists.linuxaudio.org">linux-audio-dev@lists.linuxaudio.org
Subject:  LAD? Circular Reasoning
Date:  Fri, 31 Aug 2007 14:59:55 +0200
Mailer:  Evolution 2.0.4-3mdk

Late one friday afternoon, a sound-engineer was sitting in his chair
admiring a brand new pair of flat frequency response monitors. He then
observed the following:

For two frequencies represented by sine-waves and an octave apart to
have the same relative loudness, the higher octave will need to have its
amplitude adjusted to half of that of the lower octave.1?

Both frequencies will then force a membrane to travel the same distance
within a given timeframe - the higher will go half as far but twice as
often than the lower - and they will also both have the same speed or
steepness at the zero-crossing.

Surprisingly, the lower frequency consumes four times as much energy
than the higher2?, although it is apparently not doing any more actual
work.


Therefore, it is a better excersize to take a walk around the block,
rather than running around in small circles.

QED

cheers! // Jens M Andreasen


1? Assuming that a saw wave has an even distribution
of harmonics and can be written as:

saw(t){ for(k = 1;k < inf;k++) rv += sin(k*t)/k; return rv * 2/M_PI}

2? Ohms law ...


attachments

imageappend Append an Image
>