Re: Tube Audio Question

>I'd substitute 'possibly wrong' actually. No-one can see into the future.
>However the scientist might have a valid rationale for his assertation. But
>no-one should 'close the gate' unless there is a clear factor involved that
>makes sense to do so.

Much makes sense.... until it doesn't. Historical examples include the
theory war between Westinghouse and Edison (Edison lost, even though
his 'science' was better at the time). But then, look now and see
chopped DC at several hundred thousand volts on power transmission
lines... so maybe Edison was right after all? That would be the point.

Isaac Asimov wrote a story called "Not Final" in 1941 that was directly
pointed to such closed gates. If you ever have the privilege of leafing
through a 1913 Encyclopedia Britannica, you will see the claim that it
includes the complete body of human knowledge. Even for the time that
was a preposterous claim but the editors believed it.

You did not follow the link. You should go back and follow it... then
you will see the reason for the cautionary on spelling.

With reference to speakers, I agree on the pretty severe limitations
for single drivers, even poorly executed multiple driver systems. And
so many things are done to avoid the necessities of physics. If the
purpose of a speaker is to move air in a controlled fashion, then it
should be pretty easy to understand that the moving of said air
requires a certain amount of energy delivered to the air. Then, there
is the question of the virtual sound stage. A violin, as a single
example produces sound directly from the string, and as a group of
harmonics reflected from the sound box. Which is why it sounds like a
violin and not a clarinet. That sound is pretty well dispersed,
_somewhat_ akin to a dome speaker. The Clarinet produces sound from a
single, small area _somewhat_ akin to a horn (or cone) speaker. If you
are off-axis from the clarinet, it will sound fine, but be less
focused. It is hard to be 'off axis' from a violin as long as you are
somewhat in front of the musician. How does this affect speaker design?
Well, a horn or cone speaker will not do well with a violin, piano,
cello, drum... but OK with a voice, horn or trumpet.... IF you are on
axis to it. A dome will do fine with all of it, if the microphone doing
the recording is carefully placed and designed. Moving on: A horn is
often chosen for efficient speaker design. It 'moves air' over a much
smaller stage (and is very directional as a result), and so requires
much less energy to drive. A dome disperses over nearly a hemisphere,
so to fill that area with sound, it has to move a great deal more air.
Down goes efficiency.

So. If one wishes to listen to music from other than a fixed point in a
given room with given speakers, lots of design decisions need to be
made. They can be solved partially with LOTS-O-POWER from the amp, they
can be solved partially with VERY EXPENSIVE SPEAKERS, using massive
magnets extracting the last bit of energy from every watt of power from
the amp, point being that they can be solved either way, but only
partially. And if/when they fail it will be around the edges, not all
the time. So, 'edges' might include a 30dB P/A source, a source that is
only 20dB P/A but reaches below ~40hz or above ~12,000hz on a regular
basis, stuff that is unusual as compared to most source played. Combine
the two, and very damned few speaker/amp combinations will do well. I
have heard some drop-dead stunning systems playing solo-voice, the only
thing in that room was the voice... no amp artifacts, nothing. But that
same combination fell flat (OK, not 'flat') when asked to play the
Saint-Saens Organ Symphony at any level above conversational. The
system simply could not move enough air when the time came.

Peter Wieck
Wyncote, PA

.

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