What Should A Sub-Woofer Do ?
It should increase the sound intensity of the lowest pipe sounds of the 16' rank
tones to be perceived at about the same loudness to the listener as the tenor
and soprano notes, or some music seems "better" if the low bass is even
heard a bit louder (depends upon taste, etc. of the organ player and seeming need
of the music). Same is absolutely true for a large number of tones from a
32' rank, pitch going on down to 16.35 Hz at lowest C pipe (equal tempered tuning).
OK, how much increase is needed: of course this varies with frequency of the tones.
Was completely examined and reexamined at the Bell Telephone Labs decades ago,
and re-examined again more recently. The following link shows the final "summary"
data released by Fletcher and Munson at Bell, and later reaffirmed well by Robinson and
Dobson. See:
http://www.webervst.com/fm.htm
This shows that for the loudness by a lowest notes of a 16' foot rank, the source must be generating
about 45 dB higher intensity (sound pressure level, or dB SPL) than a note at Middle C (261.63 Hz).
Musical scale note frequencies are listed at the following link, note Middle is C4, see:
http://www.phy.mtu.edu/~suits/notefreqs.html
Achieving the needed sound loudness increases as the notes go lower is the
task performed by the sub-woofer. Which woofer to use? Many opinions!
Some folks and music (theatre style) might want even more intense bass, at least a
few of the instrument ranks, than implied here.
It should increase the sound intensity of the lowest pipe sounds of the 16' rank
tones to be perceived at about the same loudness to the listener as the tenor
and soprano notes, or some music seems "better" if the low bass is even
heard a bit louder (depends upon taste, etc. of the organ player and seeming need
of the music). Same is absolutely true for a large number of tones from a
32' rank, pitch going on down to 16.35 Hz at lowest C pipe (equal tempered tuning).
OK, how much increase is needed: of course this varies with frequency of the tones.
Was completely examined and reexamined at the Bell Telephone Labs decades ago,
and re-examined again more recently. The following link shows the final "summary"
data released by Fletcher and Munson at Bell, and later reaffirmed well by Robinson and
Dobson. See:
http://www.webervst.com/fm.htm
This shows that for the loudness by a lowest notes of a 16' foot rank, the source must be generating
about 45 dB higher intensity (sound pressure level, or dB SPL) than a note at Middle C (261.63 Hz).
Musical scale note frequencies are listed at the following link, note Middle is C4, see:
http://www.phy.mtu.edu/~suits/notefreqs.html
Achieving the needed sound loudness increases as the notes go lower is the
task performed by the sub-woofer. Which woofer to use? Many opinions!
Some folks and music (theatre style) might want even more intense bass, at least a
few of the instrument ranks, than implied here.
Jim Reid