Contrabass Digest

2000-08-24

From: FOLLASRW
Date: Thu, 24 Aug 2000 09:57:02 EDT
Subject: Re: [CB] [Contra Digest]

The number of cycles occurring during the length of a note is not the
determining factor of pitch: It is the number of cycles per second.   A BBb
which vibrates 8 times during a quarter note at 218 bpm still has a frequency
of approximately 29Hz, or 29 cycles per second.  Even if the note is as short
as a quarter note, enough vibrations are present for the listener to
recognize a pitch.  The issue becomes problematic when there are too few
vibrations to create a pitch, for example, a staccato note in the lowest
contra range.  Creating only one Hz does not give the ear enough information
to create a physical comparison for pitch.  Hertz is a physical description
of cycles PER SECOND, not cycles created.

Ron Follas

In a message dated 8/23/00 6:29:01 PM, The List writes:

<<
Staccato notes have frequency components from the starting and stopping that
is clearly audible well below the supposed hearing limit of 20Hz.  Say if you
play a BBb quarter note at 218 bpm, the note is only eight cycles long.  This
is within normal technique on five string bass guitar, I haven't recorded
brass or reeds yet.

If you do a Fourier analysis, you will find that a series of such notes has a
strong frequency of 3.64Hz  (BBBBBb).  I have found that this frequency  is
"heard" at normal listening levels by 100% of my test subjects.

Conventional bass speakers have resonances in the lower octaves and roll off
the bass above this hearing range so that the pitch and rhythm of staccato
notes is audibly distorted.  For this reason either the low frequency content
or dynamics are limited in 99% of all recordings.

I have been searching for recordings with extreme low bass of a percussive
nature.  This sound was nearly impossible to capture on vinyl, but is well
within CD technology - it just doesn't match commercially available speakers.
It can be heard through good closed-ear headphones made by Sennheiser, Sony,
Koss and Beyerdynamic which have response beolw 10Hz.

There is also a limit of conventional microphones, because of either
capacitors or transformers in the signal path which roll off bass at 20-30Hz.
Can anybody recommend extreme bass acoustic recordings, or is anyone near
Greenwich, CT, interested in making some?  (I just got a microphone that is
flat to 10Hz)

Larry de Martin
 >>

***End of Contrabass Digest***

 
Next Digest ->
Previous Digest <-
Index
Top