From: "Arny Krueger"
Date: 4/26/2004 2:45 AM Pacific Standard Time
Message-id:

S888Wheel wrote:

I made my claim about 6 hz with the
assumption that it would be taken within the context of high end
audio and the recording and playback of music.

So far so good.

Clearly some people on
RAHE find 6 hz tones useful for things that exist outside of those
parameters.

The other, non-audio related uses of infrasonic sound are irrelevant. Just
another straw man argument.

It wasn't an argument. I was simpoly pointing out that some people are
interested in the use of 6 hz tones outside of high end audio and the recording
and playback of music. I thought in consideration of those other interests held
by other people that we should clearly define the parameters of usefulness for
this discussion. I will happily discuss it within the parameters of high end
audio, the recording and playback of music.


Fourier analysis proves that any musical sound can be analyzed and found to
be a collection of tones.

http://music.arts.uci.edu/dobrian/digitalaudio.htm

Indeed it does. Your source also clearly indicates that the lowest tone any
instrument can produce is the fundimental tone. So the lowest tone needed to
reproduce any acoustical instrument in the real world is just above 16 hz.




High quality recordings of a number of musical works, both classical and
popular, have been analyzed and found to contain substantial content at
frequencies at or near 6 Hz, and lower.

http://www.smr-home-theatre.org/Sub-...How-Low-2.html

I have never said there are no CDs containing such content. I have said that
such content is of no use. Hopefully you will remember the context in which I
am making that claim. IMO it is unlikely that any of that content is anything
other than cheap effects and garbage, We can be pretty sure none of it is of
any acoustic musical instrument. If you can find the specifics of any such low
frequency content then we can discuss it's merits. For instance, I would be
very keen to know what microphone was used to record any of these low
frequencies. I would be curious to know the levels of such content as well. We
can then figure out if the content was or was not mangled to the point of pure
garbage at the point of recording and we can figure out whether or not there is
audible content or just enough energy to shake the listening room which is in
effect garbage because no such listening room was present at the recording.



Furthermore, it has been found that the means generally used to reduce or
eliminate 6 Hz tones from recordings have reliably audible effects on the
rest of the recording.


This is a bit of a broad assertion. What are those means "generally used" that
you are refering to? What are other means used? What audible effects can we say
for sure these different means of attenuating low frequencies 6hz and below)
have on the recording and playback? Without an investigation of these questions
we cannot say that 6 hz tones are "useful" or not.


The Subjective Importance of Uniform Group Delay at Low Frequencies
Author(s): Fincham, L. R.
Publication: JAES Volume 33 Number 6 pp. 436·439; June 1985
Abstract: Analog recordings always have high group delay at low frequencies
due to the combined effects of all the components in the record/replay
chain, and in particular the analog recorder. Digital recorders now make it
practical to remove much of this group delay. It is discussed whether it is
worthwhile to produce a record/replay chain having uniform

High fidelity is about approaching the quality of the original sound that
was recorded, as closely as possible. Eliminating musical content, and/or
intentially making alterations that adversely affect sound quality seem to
be the opposite of high fidelity.

http://encyclopedia.thefreedictionar...igh%20fidelity

http://en.wikipedia.org/wiki/High_fidelity



I don't see any evidence of "musical" content at 6 hz. There are recordinbg
engineers that seem to think not filtering 6 hz tones and others in that region
will adversely affect the recording. If the mic can't relaibly record such
content without gross distortion that content is simply garbage that does harm
to the final recording if it does anything at all.


Now if you wish to discuss the topic of what I think is
useful in the way of low frequency extension we must establish the
parameters of use.

The stated context of high end audio and recording and playback of music
seems to be just fine.






Excellent. Thank you for your post. My compliments for keeping it about audio.