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electrostatic question

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Anonymous
June 7, 2005 5:13:00 PM

Archived from groups: rec.audio.pro (More info?)

how "fast" does a quality electrostatic loudspeaker membrane return to
it's "resting state" after it's been hit with program material?

Earthworks mics were saying they have a super-fast return to resting
state. I thought that was a cool feature for a mic to have, so I was
wondering if 'stats are faster-returning than cone/tweeter loudspeakers
(assuming good build quality in both types).

More about : electrostatic question

Anonymous
June 7, 2005 9:26:29 PM

Archived from groups: rec.audio.pro (More info?)

In article <1118175180.557742.239650@g47g2000cwa.googlegroups.com>,
<genericaudioperson@hotmail.com> wrote:
>how "fast" does a quality electrostatic loudspeaker membrane return to
>it's "resting state" after it's been hit with program material?
>
>Earthworks mics were saying they have a super-fast return to resting
>state. I thought that was a cool feature for a mic to have, so I was
>wondering if 'stats are faster-returning than cone/tweeter loudspeakers
>(assuming good build quality in both types).

For the most part, the effective slew rate of a ribbon or electrostatic
tweeter is very good because of the low mass of the moving part and the
large amount of force that can be applied to it.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Anonymous
June 7, 2005 11:36:15 PM

Archived from groups: rec.audio.pro (More info?)

Thanks for the responses, Gentlemen.

I learned a lot from your responses, but I might not have stated the
key thing I was trying to figure out clearly enough:

Let's say you have a really sharp impulse sound that dies
immediately... like a woodblock hit or something with an even tighter
attack and sharper decay.

Which loudspeaker would return to zero-sound output quicker, the
electrostatic speaker or a cone/tweeter design like a Genelec 1029 or a
Mackie HR-824?

Or put in car terms, which type of speaker can come to a "dead stop"
quicker?
Related resources
Anonymous
June 8, 2005 12:28:35 AM

Archived from groups: rec.audio.pro (More info?)

wow, thanks Phil! that was very informative for me.

i'm disciplining myself to pay some bills and lay low for a while. but
when it's time for me to jump into a serious set of speakers, i'm
checking out 'stats first and foremost. i can't see myself getting
anything but a set of 'stats at this point.
Anonymous
June 8, 2005 3:27:46 AM

Archived from groups: rec.audio.pro (More info?)

On 7 Jun 2005 13:13:00 -0700, genericaudioperson@hotmail.com wrote:

>how "fast" does a quality electrostatic loudspeaker membrane return to
>it's "resting state" after it's been hit with program material?
>
>Earthworks mics were saying they have a super-fast return to resting
>state. I thought that was a cool feature for a mic to have, so I was
>wondering if 'stats are faster-returning than cone/tweeter loudspeakers
>(assuming good build quality in both types).

Microphones, unlike loudpseakers, do not couple significantly to
the air around them. They sit like little flies on the wall,
obeserving, but not influencing.

A loudspeaker's conversion efficiency (percentage watts out for
a given watts in) is directly related to its ability to couple
to the surrounding air.

Electrostatic speakers are very tightly coupled, and so have
high conversion efficiency, despite mistaken rumors otherwise.
Because of this, their effective moving mass includes a
considerable amount of surrounding air.

If you were to imagine a electrostatic, or any other speaker,
operating in a vacuum, the analogy to microphones might apply
better.

Good fortune,

Chris Hornbeck
"What, never?"
"No, never."
"What, never?"
"Well, hardly ever."
"HMS Pinafore"
Anonymous
June 8, 2005 7:46:29 AM

Archived from groups: rec.audio.pro (More info?)

On 7 Jun 2005 19:36:15 -0700, genericaudioperson@hotmail.com wrote:

>Thanks for the responses, Gentlemen.
>
>I learned a lot from your responses, but I might not have stated the
>key thing I was trying to figure out clearly enough:
>
>Let's say you have a really sharp impulse sound that dies
>immediately... like a woodblock hit or something with an even tighter
>attack and sharper decay.
>
>Which loudspeaker would return to zero-sound output quicker, the
>electrostatic speaker or a cone/tweeter design like a Genelec 1029 or a
>Mackie HR-824?
>
>Or put in car terms, which type of speaker can come to a "dead stop"
>quicker?

Let me turn the question around to you: given a choice between a high
mass small geometry driver and a low mass large geometry driver,
which will (all other things, blah-blah) more faithfully generate
an accurate wavefront? (At high speeds, your issue)

Methinks that's your real question, and it's a good one. The fact
that you can ask it also makes me think you can answer it. Maybe
start by thinking about the near-field case first, then worrying
about the far-field later.

Good fortune,

Chris Hornbeck
"What, never?"
"No, never."
"What, never?"
"Well, hardly ever."
"HMS Pinafore"
Anonymous
June 8, 2005 8:46:14 AM

Archived from groups: rec.audio.pro (More info?)

> Which loudspeaker would return to zero-sound output quicker, the
> electrostatic speaker or a cone/tweeter design like a Genelec 1029
> or a Mackie HR-824?

The electrostatic. Why do you think 'stats "sound better"?

The greater the mass per unit area, the less damped the driver is. Dynamic
drivers are worse in this regard than electrostatic.
Anonymous
June 8, 2005 12:29:36 PM

Archived from groups: rec.audio.pro (More info?)

In article <1118198175.149034.236350@o13g2000cwo.googlegroups.com>,
<genericaudioperson@hotmail.com> wrote:
>electrostatic speaker or a cone/tweeter design like a Genelec 1029 or a
>Mackie HR-824?
>
>Or put in car terms, which type of speaker can come to a "dead stop"
>quicker?

That depends on the frequency of excitation, and how well-designed the
speaker is.

Take a look at the speaker reviews in Stereophile, which have reasonably
accurate waterfall plots of amplitude decay vs. frequency. It is impressive
to see how much variance from one design to another exists, and there is
a pretty good correlation between impulse response and perceived sound too.

I have seen some monkey boxes that looked pretty good. The plot on the
HR-824 looks a whole lot better than the plot on the 1029. I have also
seen some electrostats that looked pretty bad, and vice-versa.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Anonymous
June 8, 2005 4:54:09 PM

Archived from groups: rec.audio.pro (More info?)

genericaudioperson@hotmail
>
> Let's say you have a really sharp impulse sound that dies
> immediately... like a woodblock hit or something with an even tighter
> attack and sharper decay.
>
> Which loudspeaker would return to zero-sound output quicker, the
> electrostatic speaker or a cone/tweeter design like a Genelec 1029 or a
> Mackie HR-824?


** The electrostatic one - by a mile.

One of the biggest faults in most loudspeakers is that the moving parts,
trapped air and enclosure structures all STORE energy and that energy must
return as sound to the room after the input signal ceases - or in practice
as a continuous additional signal ( distortion) that is not part if the
input. The technical name for this is "overhang" - the major cause of
coloration in the sound of loudspeakers.

Because the moving part ( ie diaphragm) of a ES speaker is extremely light
weight and is driven evenly all over it surface ( unlike cone/dome drivers
that are driven via the edge of a coil ) it has almost no ability to store
energy in the first place. Pretty much, an ES diaphragm starts moving
instantly a signal is applied and stops moving instantly it ceases.

Folk who have spent their lives listening to highly coloured dynamic
speakers ( like JBL or AR) find on first hearing the sound of a good ( ie
Quad) ESL that the sound is quite eerie - voices in particular sound too
real for comfort.




............ Phil
Anonymous
June 9, 2005 4:33:28 AM

Archived from groups: rec.audio.pro (More info?)

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3gn4ujFd5mjlU1@individual.net...
>
> genericaudioperson@hotmail
>>
>> Let's say you have a really sharp impulse sound that dies
>> immediately... like a woodblock hit or something with an even tighter
>> attack and sharper decay.
>>
>> Which loudspeaker would return to zero-sound output quicker, the
>> electrostatic speaker or a cone/tweeter design like a Genelec 1029 or a
>> Mackie HR-824?
>
>
> ** The electrostatic one - by a mile.
>
> One of the biggest faults in most loudspeakers is that the moving parts,
> trapped air and enclosure structures all STORE energy and that energy must
> return as sound to the room after the input signal ceases - or in
> practice as a continuous additional signal ( distortion) that is not part
> if the input. The technical name for this is "overhang" - the major
> cause of coloration in the sound of loudspeakers.
>
> Because the moving part ( ie diaphragm) of a ES speaker is extremely light
> weight and is driven evenly all over it surface ( unlike cone/dome
> drivers that are driven via the edge of a coil ) it has almost no ability
> to store energy in the first place. Pretty much, an ES diaphragm starts
> moving instantly a signal is applied and stops moving instantly it ceases.
>
> Folk who have spent their lives listening to highly coloured dynamic
> speakers ( like JBL or AR) find on first hearing the sound of a good ( ie
> Quad) ESL that the sound is quite eerie - voices in particular sound
> too real for comfort.

Are those the "voices" you hear in your head Phil?

>
>
>
>
> ........... Phil
>
>
Anonymous
June 9, 2005 9:55:12 AM

Archived from groups: rec.audio.pro (More info?)

<genericaudioperson@hotmail.com> wrote in message
news:1118198175.149034.236350@o13g2000cwo.googlegroups.com...

> I learned a lot from your responses, but I might not have
stated the
> key thing I was trying to figure out clearly enough:

> Let's say you have a really sharp impulse sound that dies
> immediately... like a woodblock hit or something with an
even tighter
> attack and sharper decay.

> Which loudspeaker would return to zero-sound output
quicker, the
> electrostatic speaker or a cone/tweeter design like a
Genelec 1029 or a
> Mackie HR-824?

I find it quite ironic when ordrinally well-informed people
throw basic electrical engineering principles out the door,
in order to mindlessly recite audiophile dogma.

Loudspeakers are at their core bandpass filters. Yes, there
are a lot of secondary effects such as diaphragm breakup,
reflections from internal and external components, etc.

But, in the end loudspeakers are bandpass filters. If you
have measurement equipment with sufficient range, most
speaker drivers act like bandpass filters with what are
ultimately 6 dB or 12 dB/octave skirts.

IOW, like the rest of the known universe, loudspeakers tend
to be and act like collections of second-order systems.

So, if I restated the question as follows:

"Which bandpass filter would return to zero-sound output
quicker?"

Most people who have some training and/or experience with
electrical engineering would answer about as follows:

"All other things being equal, the bandpass filter with the
highest upper corner frequency would would return to
zero-sound output quicker"

> Or put in car terms, which type of speaker can come to a
"dead stop"
> quicker?

All other things being equal, the loudspeaker with the
highest upper corner frequency.

AFAIK the current generally-avaialable commercial
loudspeakers drivers with the highest upper corner
frequencies are essentially dome tweeters.

While it seems like planar or ribbon speakers should have
the highest upper corner frequencies, when the sound waves
hit the calibrated microphones, they frequently fall short.

AFAIK the reason for planar speakers to tend to have
relatively low upper corner frequencies is mechanical, and
that it is actually quite difficult to generate high force
levels compared to the weight of a given area of the
diaphragm, using a planar or ribbon design. If the planar or
ribbon is electrodynamic, the magnetic motor structures tend
to be inefficient. Electrostatic planar speakers require
very high signal voltages to generate high force levels, and
if operated at high voltages, they tend to fall prey to
various kinds of electrical breakdown.

Plasma-based speakers seem to be a third approach that would
have the potential to develop very high corner frequencies.
However, commercial designs based on plasma are very rare
and tend to be very expensive.

BTW, given that conventional drivers can easily have corner
frequencies higher than the frequency range of the human
ear, and that human hearing actually has fairly poor phase
and transient response, the question is moot.
Anonymous
June 9, 2005 9:55:13 AM

Archived from groups: rec.audio.pro (More info?)

> I find it quite ironic when ordrinally well-informed people
> throw basic electrical engineering principles out the door,
> in order to mindlessly recite audiophile dogma.

I find it unfortunate when supposedly educated people don't stop to think
about basic principles.


> Loudspeakers are at their core bandpass filters. Yes, there
> are a lot of secondary effects such as diaphragm breakup,
> reflections from internal and external components, etc.

> But, in the end loudspeakers are bandpass filters. If you
> have measurement equipment with sufficient range, most
> speaker drivers act like bandpass filters with what are
> ultimately 6 dB or 12 dB/octave skirts.

You are assuming that the bandpass-filter model is the only significant
aspect of the speaker's behavior.


> So, if I restated the question as follows:

> "Which bandpass filter would return to zero-sound output
> quicker?"

....you'd be asking an invalid question.

The correct (?) question is... Which driver dissipates its kinetic energy
most rapidly when the signal is removed? Hint: it's the driver with lowest
unit mass.

Driver bandwidth is only indirectly related to sound quality, because it's
determined by only one set of driver properties. It ignores the relationship
between the driver and the air load it moves. Given a planar driver with the
same open-air resonance as a cone driver, the former is going to STOP
FASTER, simply because it's better-damped by the air.

The analogy is simple... Should a driver be a golf ball or a ping-pong ball?
Think about it.


As for plasma speakers... Have you ever actually heard the Plasmatronics
playing live master tapes? I have. I worked in a store that sold them.

Nothing has ever come as close to actually sounding like "the real thing".
Anonymous
June 9, 2005 12:13:50 PM

Archived from groups: rec.audio.pro (More info?)

"William Sommerwerck" <williams@nwlink.com> wrote in message
news:11agbmgrio31i4a@corp.supernews.com...
> > I find it quite ironic when ordrinally well-informed
people
> > throw basic electrical engineering principles out the
door,
> > in order to mindlessly recite audiophile dogma.
>
> I find it unfortunate when supposedly educated people
don't stop to think
> about basic principles.
>
>
> > Loudspeakers are at their core bandpass filters. Yes,
there
> > are a lot of secondary effects such as diaphragm
breakup,
> > reflections from internal and external components, etc.
>
> > But, in the end loudspeakers are bandpass filters. If
you
> > have measurement equipment with sufficient range, most
> > speaker drivers act like bandpass filters with what are
> > ultimately 6 dB or 12 dB/octave skirts.
>
> You are assuming that the bandpass-filter model is the
only significant
> aspect of the speaker's behavior.

Not a bad assumption, considering the breadth of the field
that is before us - thousands of designs, numerous basic
technologies, etc.

> > So, if I restated the question as follows:

> > "Which bandpass filter would return to zero-sound output
> > quicker?"

> ...you'd be asking an invalid question.

Perhaps, perhaps not. In the end everything is just a
collection of second order systems.

> The correct (?) question is... Which driver dissipates its
kinetic energy
> most rapidly when the signal is removed? Hint: it's the
driver with lowest
> unit mass.

Wrong, rate of dissipation of energy relates to things like
efficiency. The usual units of dissipation of energy are
watts per second, right?

Besides, you want us all to think that planar speakers can't
ring, or that they aren't basically collections of second
order systems?

> Driver bandwidth is only indirectly related to sound
quality, because it's
> determined by only one set of driver properties. It
ignores the relationship
> between the driver and the air load it moves. Given a
planar driver with the
> same open-air resonance as a cone driver, the former is
going to STOP
> FASTER, simply because it's better-damped by the air.

Last time I looked, free-air resonance is an effect that we
worry about at the low end of the audio spectrum, not the
top.

> The analogy is simple... Should a driver be a golf ball or
a ping-pong ball?

I think there are examples of both that in some sense work.

> Think about it.

Been there, done that.

> As for plasma speakers... Have you ever actually heard the
Plasmatronics
> playing live master tapes?

Yes, at Hal Kacholsky's (sp?) in Westchester county, NY I
think it was. I lose track of the city names out there. ;-)

>I have. I worked in a store that sold them.

> Nothing has ever come as close to actually sounding like
"the real thing".

Please see my specific comments about plasma speakers. I
didn't count their performance out, but I did point out that
they are very rare and tend to be very expensive to own and
operate. Did I mention the potential life and property
dangers and regulatory issues? No. I should.

Heck, in the Plasmatronics days we had tone arms with live
liquid mercury in open vats. Wow!

Would you buy a house from someone who had liquid mercury in
vats laying out in their living room?
Anonymous
June 9, 2005 7:34:58 PM

Archived from groups: rec.audio.pro (More info?)

> > The correct (?) question is... Which driver dissipates its
> kinetic energy
> > most rapidly when the signal is removed? Hint: it's the
> driver with lowest unit mass.

> Wrong, rate of dissipation of energy relates to things like
> efficiency. The usual units of dissipation of energy are
> watts per second, right?

Not so. Most drivers are highly inefficient. Most of the energy used to get
them moving is never converted into audible sound.


> Besides, you want us all to think that planar speakers can't
> ring, or that they aren't basically collections of second
> order systems?

Of course not. I'm simply saying that seeing a driver as little more than a
second-order bandpass filter ignores other significant factors.


> > The analogy is simple... Should a driver be a golf ball or
> a ping-pong ball?
>
> I think there are examples of both that in some sense work.
>
> > Think about it.
>
> Been there, done that.

If you had, you'd understand the principles involved.


> Please see my specific comments about plasma speakers. I
> didn't count their performance out, but I did point out that
> they are very rare and tend to be very expensive to own and
> operate. Did I mention the potential life and property
> dangers and regulatory issues? No. I should.

> Heck, in the Plasmatronics days we had tone arms with live
> liquid mercury in open vats. Wow!

> Would you buy a house from someone who had liquid mercury in
> vats laying out in their living room?

Perhaps. I have been told that liquid mercury, though poisonous, is not as
dangerous as organic-mercury compouns.
Anonymous
June 10, 2005 1:13:58 AM

Archived from groups: rec.audio.pro (More info?)

"Arny Krueger"
>
> I find it quite ironic when ordrinally well-informed people
> throw basic electrical engineering principles out the door,
> in order to mindlessly recite audiophile dogma.


** Which is exactly what Arny is about to do.

Plus use a truly bizarre false analogy.


> Loudspeakers are at their core bandpass filters. Yes, there
> are a lot of secondary effects such as diaphragm breakup,
> reflections from internal and external components, etc.
>
> But, in the end loudspeakers are bandpass filters.


** Arny sets up the false analogy - one that has only a superficial
connection to the facts of the question.


> If you
> have measurement equipment with sufficient range, most
> speaker drivers act like bandpass filters with what are
> ultimately 6 dB or 12 dB/octave skirts.


** Part 2 of the false analogy.


> IOW, like the rest of the known universe, loudspeakers tend
> to be and act like collections of second-order systems.


** Now Arny makes a giant leap from the particular to the general - watch
out for the coming back flip that completes the stunt.



> So, if I restated the question as follows:
>
> "Which bandpass filter would return to zero-sound output
> quicker?"


** Here is goes - the flawed analogy has now become a predicting model !!



>> Most people who have some training and/or experience with
> electrical engineering would answer about as follows:
>
> "All other things being equal, the bandpass filter with the
> highest upper corner frequency would would return to
> zero-sound output quicker"


** Truisms about the false model are now about to be foisted back onto the
question is hand. This is getting exciting - I can't wait to see how
wacko this gets !!!


>> Or put in car terms, which type of speaker can come to a
> "dead stop" quicker?
>
> All other things being equal, the loudspeaker with the
> highest upper corner frequency.


** Errr - the reality is that nearly all hi-fi speakers have upper
corner frequencies that equal or exceed the range of human hearing. Has
Arny abandoned the concept of "audible" effects completely ?????


> AFAIK the current generally-avaialable commercial
> loudspeakers drivers with the highest upper corner
> frequencies are essentially dome tweeters.


** Errr - but a tweeter is not a "loudspeaker" at all.

Has Arny decided to re-define the OP's question to suit this evil game ???


> While it seems like planar or ribbon speakers should have
> the highest upper corner frequencies, when the sound waves
> hit the calibrated microphones, they frequently fall short.


** Hang on a minute - is this some new phenomenon ??

" Heavyweight high frequencies that fall under gravity ??? "


( snip some very esoteric ramblings)


> BTW, given that conventional drivers can easily have corner
> frequencies higher than the frequency range of the human
> ear, and that human hearing actually has fairly poor phase
> and transient response, the question is moot.


** Bloody heck !!!

Arny was just having a lend of us all along.

A giant Kreuger verbal fart engineered to blow the minds of the terminally
gullible !!!





........... Phil
Anonymous
June 10, 2005 5:53:50 AM

Archived from groups: rec.audio.pro (More info?)

Arny Krueger wrote:

> "All other things being equal, the bandpass filter with the
> highest upper corner frequency would would return to
> zero-sound output quicker"

Or in terms of high school physics, the lighter it is the
faster it will accelerate when a given force is applied and
the sooner it will stop when the force is removed. Inertia
and all that.

When I was first looking at ESL's many, many years ago I
remember reading that a practical diaphragm can be as light
as a quarter inch of air. I'm too lazy to look up material
thickness and densities to know if that's true or not but it
proved hard to forget nonetheless.



Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
June 10, 2005 7:20:24 AM

Archived from groups: rec.audio.pro (More info?)

> Or in terms of high school physics, the lighter it is the
> faster it will accelerate when a given force is applied and
> the sooner it will stop when the force is removed. Inertia
> and all that.

The membrane may be very light but the electrostatic force is weak.
Anonymous
June 10, 2005 8:28:42 AM

Archived from groups: rec.audio.pro (More info?)

This is directed to Arny, but everyone should read and heed.

In the comic strip "Non Sequitur," Danae is pushing her current theory of
theories -- you make up your mind about something, a priori, and then reject
everything that doesn't fit. Rejection includes putting your fingers in your
ears and chanting "la, la, la".

It's easy (and accurate) to accuse subjectivists of this, but people who
claim to be "scientists" are supposedly immune to such criticism, because
they don't do such things. Well, they do.

I woul suggest that anyone who thinks the behavior of speaker drivers is
principally determined by their bandpass characteristics have a look at
Peter Walker's 1980 article in the JAES about the development of the ESL-63.
He specifically discusses the advantages of a driver whose mass is
significantly lower than the air load it "looks into".

One of these is that, the lower the unit-mass of the driver, the less
"reactive" its motion. That is, it's harder for the driver to move on its
own. And that's one of the most-important things we want in a driver.
Anonymous
June 10, 2005 9:57:21 AM

Archived from groups: rec.audio.pro (More info?)

Bob Cain wrote:
> Arny Krueger wrote:
>
>> "All other things being equal, the bandpass filter with
the
>> highest upper corner frequency would would return to
>> zero-sound output quicker"
>
> Or in terms of high school physics, the lighter it is the
> faster it will accelerate when a given force is applied
and
> the sooner it will stop when the force is removed.
Inertia
> and all that.

I'm from the F=MA school of thought. If you want more
accelleration, you can increase F, or decrease M or both.

> When I was first looking at ESL's many, many years ago I
> remember reading that a practical diaphragm can be as
light
> as a quarter inch of air.

But the force that acts on them is about as substantial as a
quarter inch of air. ;-)

> I'm too lazy to look up material
> thickness and densities to know if that's true or not but
it
> proved hard to forget nonetheless.

F=MA just goes around and around in my mind. I need a cup of
coffee! ;-)
June 10, 2005 11:02:28 AM

Archived from groups: rec.audio.pro (More info?)

William Sommerwerck wrote:
> This is directed to Arny, but everyone should read and heed.
>
> In the comic strip "Non Sequitur," Danae is pushing her current theory of
> theories -- you make up your mind about something, a priori, and then reject
> everything that doesn't fit. Rejection includes putting your fingers in your
> ears and chanting "la, la, la".

I think this is known as "The G W Bush method"

Steve

> It's easy (and accurate) to accuse subjectivists of this, but people who
> claim to be "scientists" are supposedly immune to such criticism, because
> they don't do such things. Well, they do.
>
> I woul suggest that anyone who thinks the behavior of speaker drivers is
> principally determined by their bandpass characteristics have a look at
> Peter Walker's 1980 article in the JAES about the development of the ESL-63.
> He specifically discusses the advantages of a driver whose mass is
> significantly lower than the air load it "looks into".
>
> One of these is that, the lower the unit-mass of the driver, the less
> "reactive" its motion. That is, it's harder for the driver to move on its
> own. And that's one of the most-important things we want in a driver.
Anonymous
June 10, 2005 12:08:14 PM

Archived from groups: rec.audio.pro (More info?)

> The membrane may be very light but the electrostatic force is weak.

"Hmmm. The Force is weak in this one...." :=P
Anonymous
June 10, 2005 1:06:10 PM

Archived from groups: rec.audio.pro (More info?)

William Sommerwerck wrote:

> One of these is that, the lower the unit-mass of the
driver, the less
> "reactive" its motion. That is, it's harder for the driver
to move on
> its own. And that's one of the most-important things we
want in a
> driver.

However, its good to avoid confusing potential causes with
actual effects.
Anonymous
June 10, 2005 6:41:15 PM

Archived from groups: rec.audio.pro (More info?)

andy wrote:
>>Or in terms of high school physics, the lighter it is the
>>faster it will accelerate when a given force is applied and
>>the sooner it will stop when the force is removed. Inertia
>>and all that.
>
>
> The membrane may be very light but the electrostatic force is weak.

Which is why the signal must be stepped up to thousands of
volts peak to peak to get decent SPL. Usually that is done
with a transformer but I've seen direct tube designs with
feedback that eliminates the distortion of a transformer
(which is already small compared to the coil-gap
configuration of a speaker.)


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
June 11, 2005 2:04:33 AM

Archived from groups: rec.audio.pro (More info?)

On Thu, 9 Jun 2005 05:55:12 -0400, "Arny Krueger" <arnyk@hotpop.com>
wrote:

>Most people who have some training and/or experience with
>electrical engineering would answer about as follows:
>
>"All other things being equal, the bandpass filter with the
>highest upper corner frequency would would return to
>zero-sound output quicker"

True, but in this case all other things are very unequal.
One is a high Q resonance; the other a low Q.

My only point in *not* answering the OP directly was that
generalizing is dangerous in this case; better to work
out a good model first and leave the rules of thumb to
*much* further down the road.

I'm just not convinced that a general answer exists.
But the models are quite understandable, and worthwhile.
It's important stuff for audio folks to know in depth,
methinks. Rubber meeting road stuff.

Chris Hornbeck
Anonymous
June 11, 2005 2:09:01 AM

Archived from groups: rec.audio.pro (More info?)

On Fri, 10 Jun 2005 04:28:42 -0700, "William Sommerwerck"
<williams@nwlink.com> wrote:

>I woul suggest that anyone who thinks the behavior of speaker drivers is
>principally determined by their bandpass characteristics have a look at
>Peter Walker's 1980 article in the JAES about the development of the ESL-63.
>He specifically discusses the advantages of a driver whose mass is
>significantly lower than the air load it "looks into".
>
>One of these is that, the lower the unit-mass of the driver, the less
>"reactive" its motion. That is, it's harder for the driver to move on its
>own. And that's one of the most-important things we want in a driver.

In electrical filter terms, this is "low Q", like "viciously
damned clueing" for tonearms.

Chris Hornbeck
Anonymous
June 11, 2005 2:09:02 AM

Archived from groups: rec.audio.pro (More info?)

> >I would suggest that anyone who thinks the behavior of speaker drivers is
> >principally determined by their bandpass characteristics have a look at
> >Peter Walker's 1980 article in the JAES about the development of the
ESL-63.
> >He specifically discusses the advantages of a driver whose mass is
> >significantly lower than the air load it "looks into".

> >One of these is that, the lower the unit-mass of the driver, the less
> >"reactive" its motion. That is, it's harder for the driver to move on its
> >own. And that's one of the most-important things we want in a driver.

> In electrical filter terms, this is "low Q", like "viciously
> damned clueing" for tonearms.

No, this has nothing to do with Q (as I understand it).
Anonymous
June 11, 2005 7:20:16 AM

Archived from groups: rec.audio.pro (More info?)

On Fri, 10 Jun 2005 15:40:49 -0700, "William Sommerwerck"
<williams@nwlink.com> wrote:

>> In electrical filter terms, this is "low Q", like "viciously
>> damned clueing" for tonearms.
>
>No, this has nothing to do with Q (as I understand it).

Okay, let me put it this way: the rock suspended by a spring
has reactive components to its motion, the (mostly) rocks'
mass and the spring's compliance.

In a frictionless abstraction, any excitation causes oscillation
that lasts forever. The frequency of that oscillation varies inversely
with the square root of the product of mass and compliance.

Sound like a familiar term from electronics? So the electronic
term "Q", the ratio of reactance to resistance in a resonant
circuit has come to be associated with electromechanical things
too.

In this context, the viscous damping from whatever sources are
the resistive component, and plugging that R into standard
electronic formulas gives correct results. Analogies drawn this
way really are very useful, conceptually and practically.

Loudspeaker drivers are complicated by being *both* motors
and rocks suspended on springs. The OP's generalizations are iffy.

By the by, been meaning to ask, are you *the* William
Sommerwerck mentioned on "Say's You"?

Thanks, as always,

Chris Hornbeck
Anonymous
June 11, 2005 12:45:00 PM

Archived from groups: rec.audio.pro (More info?)

>> No, this has nothing to do with Q (as I understand it).

> Okay, let me put it this way: the rock suspended by a spring
> has reactive components to its motion, the (mostly) rocks'
> mass and the spring's compliance.

> In a frictionless abstraction, any excitation causes oscillation
> that lasts forever. The frequency of that oscillation varies inversely
> with the square root of the product of mass and compliance.

> Sound like a familiar term from electronics? So the electronic
> term "Q", the ratio of reactance to resistance in a resonant
> circuit has come to be associated with electromechanical things
> too.

> In this context, the viscous damping from whatever sources are
> the resistive component, and plugging that R into standard
> electronic formulas gives correct results. Analogies drawn this
> way really are very useful, conceptually and practically.

> Loudspeaker drivers are complicated by being *both* motors
> and rocks suspended on springs. The OP's generalizations are iffy.

You're absolutely correct, but one does not normally think of the damping
provided by the air load ("in front of" the driver) as having a significant
effect on the driver's Q. For example, large planar drivers can have a very
high fundamental-resonance Q, but still are heavily damped by the air load.

I consider this an "open" issue, and don't feel I really understand what's
going on. (I'm going to call JD later today; maybe he can explain it.)

Speaking of "vicious" damping... There's a classic Rodrigues cartoon in
which a clueless hi-fi salesman informs a customer that "Yep, this is about
the most viciously damped arm you can buy". Or something to that effect.

I consider myself privileged to own the original of Rodrigues's classic
"life-support machine" cartoon.


> By the by, been meaning to ask, are you *the*
> William Sommerwerck mentioned on "Say's You"?

You left out "inimitable".

Yes, I am he. I've sent them tons of stuff, most of it better than what they
used. Perhaps they'll use more. My anagrammies are wonderful. Here's the
clue for one of my favorites...

"Hollywood goddess's rodent-racing facilities"

I won't give you the answer, because when you figure it out, you'll be
rolling on the floor in laughter. Or shaking your head in disbelief. ("What
a weirdo.")
Anonymous
June 11, 2005 5:01:30 PM

Archived from groups: rec.audio.pro (More info?)

"Bob Cain"
>>
>>
>> The membrane may be very light but the electrostatic force is weak.
>
> Which is why the signal must be stepped up to thousands of volts peak to
> peak to get decent SPL. Usually that is done with a transformer but I've
> seen direct tube designs with feedback that eliminates the distortion of a
> transformer ...



** That is utter madness.

A tube amp has far more THD than a (correctly designed) transformer.




........... Phil
Anonymous
June 11, 2005 5:01:31 PM

Archived from groups: rec.audio.pro (More info?)

Phil Allison wrote:
> "Bob Cain"
>
>>>
>>>The membrane may be very light but the electrostatic force is weak.
>>
>>Which is why the signal must be stepped up to thousands of volts peak to
>>peak to get decent SPL. Usually that is done with a transformer but I've
>>seen direct tube designs with feedback that eliminates the distortion of a
>>transformer ...
>
>
>
>
> ** That is utter madness.
>
> A tube amp has far more THD than a (correctly designed) transformer.

You do understand linearizing feedback, right?


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
June 11, 2005 5:01:32 PM

Archived from groups: rec.audio.pro (More info?)

On Fri, 10 Jun 2005 20:29:08 -0700, Bob Cain
<arcane@arcanemethods.com> wrote:

>> A tube amp has far more THD than a (correctly designed) transformer.
>
>You do understand linearizing feedback, right?

And, perhaps surprisingly, appropriate numbers of push-pull
paralleled 211/VT4C's can be spectacularly linear before
feedback while swinging 1400 volts peak-to-peak into
each stator.

Including the loadline curvature from parasitic capacitance.

It's almost universally canonical to mock the linearity of
vacuum tubes, but it's fundamentally misplaced. And in the
higher voltage ranges, where they come alive, performance
can be amazing to jaded modern viewpoints.

Many smaller signal tubes, like 12AX7's, 6SN7's, 5687's, etc.
are more linear than *any* other device used for the same
purpose. Impedances are scaled up maybe two orders of
magnitude, raising costs and limiting flexiblity.

But for intrinsic linearity, we still have a ways to go
to better some devices designed before the Big War.

Thanks for letting me get that out. I feel better now.

Chris Hornbeck
Anonymous
June 11, 2005 5:57:27 PM

Archived from groups: rec.audio.pro (More info?)

>> "Bob Cain"
>>
>>>>
>>>>The membrane may be very light but the electrostatic force is weak.
>>>
>>>Which is why the signal must be stepped up to thousands of volts peak to
>>>peak to get decent SPL. Usually that is done with a transformer but I've
>>>seen direct tube designs with feedback that eliminates the distortion of
>>>a transformer ...
>>
>>
>> ** That is utter madness.
>>
>> A tube amp has far more THD than a (correctly designed) transformer.
>
> You do understand linearizing feedback, right?


** Typical worthless, smartarse reply from one of the ripest nut cases on
usenet.





............. Phil
Anonymous
June 11, 2005 5:57:28 PM

Archived from groups: rec.audio.pro (More info?)

Phil Allison wrote:
>>>"Bob Cain"
>>>
>>>
>>>>>The membrane may be very light but the electrostatic force is weak.
>>>>
>>>>Which is why the signal must be stepped up to thousands of volts peak to
>>>>peak to get decent SPL. Usually that is done with a transformer but I've
>>>>seen direct tube designs with feedback that eliminates the distortion of
>>>>a transformer ...
>>>
>>>
>>>** That is utter madness.
>>>
>>> A tube amp has far more THD than a (correctly designed) transformer.
>>
>>You do understand linearizing feedback, right?
>
>
>
> ** Typical worthless, smartarse reply from one of the ripest nut cases on
> usenet.

I.e.., Phil Allison doesn't understand. I'd try and explain
it but Phil Allison's ability to understand is questionable
at best. Phil Allison's reliance on slurs when things get
over his head indicates otherwise.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
June 11, 2005 6:20:04 PM

Archived from groups: rec.audio.pro (More info?)

"Chris Hornbeck"
>>
>>> A tube amp has far more THD than a (correctly designed) transformer.
>>
>>You do understand linearizing feedback, right?
>
> And, perhaps surprisingly, appropriate numbers of push-pull
> paralleled 211/VT4C's can be spectacularly linear before
> feedback while swinging 1400 volts peak-to-peak into
> each stator.


** Pure " tube head " insanity - from any engineering or economic view.

Normal for a lunatic like Hornbeck.




.............. Phil
Anonymous
June 11, 2005 6:20:05 PM

Archived from groups: rec.audio.pro (More info?)

On Sat, 11 Jun 2005 14:20:04 +1000, "Phil Allison"
<philallison@tpg.com.au> wrote:

>> And, perhaps surprisingly, appropriate numbers of push-pull
>> paralleled 211/VT4C's can be spectacularly linear before
>> feedback while swinging 1400 volts peak-to-peak into
>> each stator.
>
>
>** Pure " tube head " insanity - from any engineering or economic view.

I no longer know what either "engineering" or "economic" mean
in a modern American context. I can say fersure that I'm a'gin
both, as currently interpreted in politics, consumer products,
medical, health infrastructure, energy policy, criminal code
policy, yadayadadon'tgetmestarted, in our modern world.

So, you tell me, what actually is *not* insane? Table's open.

> Normal for a lunatic like Hornbeck.

Glad to amuse,

Chris Hornbeck
Anonymous
June 12, 2005 3:06:30 AM

Archived from groups: rec.audio.pro (More info?)

On Sat, 11 Jun 2005 08:45:00 -0700, "William Sommerwerck"
<williams@nwlink.com> wrote:

>> Loudspeaker drivers are complicated by being *both* motors
>> and rocks suspended on springs. The OP's generalizations are iffy.
>
>You're absolutely correct, but one does not normally think of the damping
>provided by the air load ("in front of" the driver) as having a significant
>effect on the driver's Q. For example, large planar drivers can have a very
>high fundamental-resonance Q, but still are heavily damped by the air load.

Perhaps a more useful appoach to the model is to say that
any particular electromechanical resonance, and loudspeaker
drivers have *lots*, has only *one* effective Q, calculated
as the RMS sum of all contributors.

'Course, this is still just one element of the OP's question.
The motor element determines the rise and fall (tangetial) slopes,
and Q determines settling time. Very roughly.

> My anagrammies are wonderful. Here's the
>clue for one of my favorites...
>
>"Hollywood goddess's rodent-racing facilities"

Still working on it. Please! don't anybody tell me.

Thanks, as always,

Chris Hornbeck
Anonymous
June 12, 2005 5:01:48 AM

Archived from groups: rec.audio.pro (More info?)

On Sat, 11 Jun 2005 08:45:00 -0700, "William Sommerwerck"
<williams@nwlink.com> wrote:

>"Hollywood goddess's rodent-racing facilities"
>
>I won't give you the answer, because when you figure it out, you'll be
>rolling on the floor in laughter. Or shaking your head in disbelief. ("What
>a weirdo.")

Not even a clue? Does it involve MM?

Please!!! don't anybody tell me the answer.

Chris Hornbeck
Anonymous
June 12, 2005 5:01:49 AM

Archived from groups: rec.audio.pro (More info?)

> Not even a clue? Does it involve MM?

No, but that's the sort of star you should be thinking of. Start listing
screen goddesses.
Anonymous
June 12, 2005 5:47:07 AM

Archived from groups: rec.audio.pro (More info?)

On Sat, 11 Jun 2005 18:18:04 -0700, "William Sommerwerck"
<williams@nwlink.com> wrote:

>> Not even a clue? Does it involve MM?
>
>No, but that's the sort of star you should be thinking of. Start listing
>screen goddesses.

My list of screen goddesses starts with Anna Karina and Monica Vitti,
but I'm guessing you've taylored this for American tastes...

Hmmm...

(Anyway, I'm very glad that it doesn't include Marilyn Monrodent.
That'd be sacreligious).

Later, tater,

Chris Hornbeck
Anonymous
June 12, 2005 12:35:26 PM

Archived from groups: rec.audio.pro (More info?)

> My list of screen goddesses starts with Anna Karina and Monica Vitti,
> but I'm guessing you've taylored this for American tastes...

No, it's not Liz Taylor, either... <grin>
!