Mind Stretchers
"Audio Empire" wrote in message
...
On Mon, 28 May 2012 09:35:45 -0700, Dick Pierce wrote
(in article ):
Audio Empire wrote:
M-L Electrostatics are push-pull and cone speakers
are single-ended. That means that harmonic distortion
in cone speakers will be much harder to control than
it is in electrostatics.
This is myth for several reasons.
I disagree.
You do so at great risk to your credibility.
Electrostatics have the diaphragm driven from both the front and
the rear using opposite phased signals. I.E, the backplane pushes on the
diaphragm (repels it) while the front plane attracts it, and vice versa.
This
makes the movement of the diaphragm more linear.
I believe this was covered well by the post you are responding to.
You are ignoring the following:
"First, the something is "push-pull" does NOT mean it is
inherently lower in distortion than something that is
single-ended. What it means is that something that is push
pull will have, if there are non linearities in the driving
force, symmetrical non-linearities which are odd-order,
as opposed non-symmetrical non-linearities which even-order."
This is a topic that in the day was well-covered by any good 2nd year EE
course.
In Magnaplaners (which are
magnetic "analogies" of electrostatics) the magnets are generally on one
side
of the diaphragm, and one side only (there have been exceptions - the
tweeter
panel in the Tympani IIIC's for instance, which had magnets on both the
front
and rear of the diaphragms), and distortion is generally higher than with
electrostatics. Also, since the speaker's efficiency falls off as the
diaphragm moves away from the magnets, Maggies are subject to dynamic
range
limitations.
In fact Magnaplanar dynamic range is typically limited by the
current-carrying capacity of the conductors on the diaphragm. IOW if you
want to listen loud, you either fry the fuses or what they are there to
protect.
I would be interested in a comparison of the cost required to achieve low
distortion peak SPLs of 120 dB over the entire audio band for magnetic
planar, ribbon, electrostatic planar, waveguide/compression horn, and direct
radiators.
While this might all be a secondary, or even a tertiary effect,
it nonetheless can be heard.
Hmm, odd order distortion or even order distortion? Which will I prefer?
For the record, my preference is neither!
The cleanest, most distortion-free speakers I've
ever heard were a pair of Martin Logan CLXs driven by a pair of Krell
solid
state monoblocks.
I seriously doubt that, as you have probably heard traditional designed
speakers with lower nonlinear and linear distortion.
A recent somewhat publicized blind preference test involving ca. $4,000 ML
systems put them last out of 4 alternatives.
Once the various technologies for building speaker drivers of a kind is
reasonably well perfected, what remains is the cost, the dynamic range, and
the control over on and off axis frequency response. That is what we hear,
not the technology that pressurizes the air.
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