As an experienced designer of speakers, I can speak with some authority
on this topic. In order to achieve the intelligibility you are looking
for you need to purchase loudspeakers that use metallic diaphragms in
the speech frequency range. (This is typically considered to be 300 -
3000 Hz.) Other materials, especially plastic cones (e.g.,
polypropylene) lose articulation as the soft diaphragm material "soaks
up" the energy imparted by the voice coil.
The trick is that the metallic diaphragms will have a high-frequency
resonance that requires special care when designing the crossover.
Otherwise, music reproduction can become "bright" or even "harsh".
There are really only a handful of speakers that will do what you are
looking for. Many of them are somewhat expensive, unfortunately.

Broadly speaking, I would group cone materials into 3 categories:

1) Metals -- by far the greatest stiffness to weight ratio.

2) Plastics -- by far the lowest stiffness to weight ratio.

3) Paper -- right about smack dab in the middle of the other two.

(By the way, things like Kevlar really fall into the same category as
other plastics -- pretty flimsy. The only way to make these things
reasonably rigid is to use a sandwich construction like Eton and Focal
(JM Lab)).

Paper is significantly more articulate than plastic. Although it's not
as good as metal in that regard, it also doesn't have nearly the same
resonance problems that afflict metals. The reason I didn't make this
recommendation to Audio-Dad is that hardly any mainstream manufacturers
use paper any more. I couldn't think of any paper cone + metal dome
designs (for example) off the top of my head that would be an obvious
recommendation for his application.

Chu Gai wrote:


Very little validity. Generalised waffle would be my description.

The reason I didn't make this
recommendation to Audio-Dad is that hardly any
mainstream manufacturers
use paper any more. .


B+C, RCF, Electrovoice, etc etc etc etc. What do you know that they don't
?!

geoff

"Chu Gai" wrote in message
oups.com...


** Beware - Google Groper TROLL


As an experienced designer of speakers, I can speak with some authority
on this topic.


** You have taken some words someone said out of context and made it
anonymous.

That is a ****ing asinine thing to do.

**** off.




........ Phil

"Peter Larsen"

Chu Gai wrote:

As an experienced designer of speakers, I can speak with
some authority on this topic.

Only one guy meets that spec in this newsgroup.



** ROTFL .......

As if this Larsen scumbag has the ****ing faintest.

What a closer cock sucker.






........ Phil

"Peter Larsen" = Scum

As an experienced designer of speakers, I can speak with
some authority on this topic.

Only one guy meets that spec in this newsgroup.

** ROTFL .......

As if this Larsen scumbag has the ****ing faintest.


I am confident that I am not the least qualified partipant in this
newsgroup.



** My gawd - does this woeful & asinine Larsen cretyn

*actually* think that is something to brag about ??

Like a slug bragging he is one up on a snail.





........ Phil

Without knowing anything else about the construction of a given driver,
choosing between paper, plastic or metal is ridiculous. There are many
variations within the formulae of each of these materials, then there is the
size and shape of the radiating surface that they become. In general, it is
a good idea to look for materials that have a good lifetime when exposed to
oxygen and ultra violet. As far as I can tell, the worst material for this
is the foam suspensions on cone type speakers. I avoid those completely.
Other than that, experience, common sense and good luck will direct you to
the right choice of driver. I have also found that the price of a given
driver is not necessarily proportional to its quality.

http://www.akrobiz.com/speakers/

BTW as soon as I get off these crutches, I will be resuming my work on three
totally new speaker systems. Each of them is a variation on a 2 way bi amp
design. There will be lots of pictures.

James. )




"Chu Gai" wrote in message
oups.com...
As an experienced designer of speakers, I can speak with some authority
on this topic. In order to achieve the intelligibility you are looking
for you need to purchase loudspeakers that use metallic diaphragms in
the speech frequency range. (This is typically considered to be 300 -
3000 Hz.) Other materials, especially plastic cones (e.g.,
polypropylene) lose articulation as the soft diaphragm material "soaks
up" the energy imparted by the voice coil.
The trick is that the metallic diaphragms will have a high-frequency
resonance that requires special care when designing the crossover.
Otherwise, music reproduction can become "bright" or even "harsh".
There are really only a handful of speakers that will do what you are
looking for. Many of them are somewhat expensive, unfortunately.

Broadly speaking, I would group cone materials into 3 categories:

1) Metals -- by far the greatest stiffness to weight ratio.

2) Plastics -- by far the lowest stiffness to weight ratio.

3) Paper -- right about smack dab in the middle of the other two.

(By the way, things like Kevlar really fall into the same category as
other plastics -- pretty flimsy. The only way to make these things
reasonably rigid is to use a sandwich construction like Eton and Focal
(JM Lab)).

Paper is significantly more articulate than plastic. Although it's not
as good as metal in that regard, it also doesn't have nearly the same
resonance problems that afflict metals. The reason I didn't make this
recommendation to Audio-Dad is that hardly any mainstream manufacturers
use paper any more. I couldn't think of any paper cone + metal dome
designs (for example) off the top of my head that would be an obvious
recommendation for his application.

"Chu Gai" wrote in message
oups.com...
As an experienced designer of speakers, I can speak with some authority
on this topic. In order to achieve the intelligibility you are looking
for you need to purchase loudspeakers that use metallic diaphragms in
the speech frequency range. (This is typically considered to be 300 -
3000 Hz.) Other materials, especially plastic cones (e.g.,
polypropylene) lose articulation as the soft diaphragm material "soaks
up" the energy imparted by the voice coil.
The trick is that the metallic diaphragms will have a high-frequency
resonance that requires special care when designing the crossover.
Otherwise, music reproduction can become "bright" or even "harsh".
There are really only a handful of speakers that will do what you are
looking for. Many of them are somewhat expensive, unfortunately.

Broadly speaking, I would group cone materials into 3 categories:

1) Metals -- by far the greatest stiffness to weight ratio.

2) Plastics -- by far the lowest stiffness to weight ratio.

3) Paper -- right about smack dab in the middle of the other two.

Shame you missed option (0) Ceramics, which are superior to metals in
this regard.

BTW, what gives you the impression that paper is superior to modern
plastic matrix composites?

(By the way, things like Kevlar really fall into the same category as
other plastics -- pretty flimsy. The only way to make these things
reasonably rigid is to use a sandwich construction like Eton and Focal
(JM Lab)).

You don't seem to have noticed that pistonic operation is not a
requirement for high quality, vide the B&W 'free edge' midrange
driver, widely regarded as among the most transparent midrange drivers
available.

And what about fabric treated with viscous liquids, such as is used by
ATC for their superb midrange dome, the heart of many studio monitors?

Paper is significantly more articulate than plastic.

What is that supposed to mean?

Although it's not
as good as metal in that regard, it also doesn't have nearly the same
resonance problems that afflict metals.

Untrue, it simply has more but less severe resonances and breakup
modes.

The reason I didn't make this
recommendation to Audio-Dad is that hardly any mainstream manufacturers
use paper any more.

Actually, nearly *all* mainstream manufacturers still use paper in
some of their models, even B&W.

I couldn't think of any paper cone + metal dome
designs (for example) off the top of my head that would be an obvious
recommendation for his application.

There are however numerous good quality paper cone + fabric or plastic
dome speakers.

--

Stewart Pinkerton | Music is Art - Audio is Engineering

"Chu Gai" wrote in message
oups.com

As an experienced designer of speakers, I can speak with
some authority on this topic.

Then what's the title line all about?


In order to achieve the
intelligibility you are looking for you need to purchase
loudspeakers that use metallic diaphragms in the speech
frequency range.

I'm thus reminded that :"some authority" can mean "very little authority" or
"bogus authority".

Where did you get the idea that metallic diaphragms are necessarily any
better or worse for speech intelligibility than anything else?

(This is typically considered to be 300
- 3000 Hz.) Other materials, especially plastic cones
(e.g., polypropylene) lose articulation as the soft
diaphragm material "soaks up" the energy imparted by the
voice coil.

In fact speech intelligibility has as much if not more to do with
reflections within the room as anything else. There's no necessary
connection between diaphragm materials and room reflections. Therefore your
whole pretext - that there is a necessary connection between diaphragm
materials and speech intellibility is questionable to say the least.

The trick is that the metallic diaphragms will have a
high-frequency resonance that requires special care when
designing the crossover.

Metallic diaphragms need not have high-frequency resonances in the normal
audible range.

Otherwise, music reproduction
can become "bright" or even "harsh". There are really
only a handful of speakers that will do what you are
looking for. Many of them are somewhat expensive,
unfortunately.

Nonsense.

Broadly speaking, I would group cone materials into 3
categories:

1) Metals -- by far the greatest stiffness to weight
ratio.

As if stiffness is always a virtue.

2) Plastics -- by far the lowest stiffness to weight
ratio.

As if stiffness is always a virtue or always a problem.


3) Paper -- right about smack dab in the middle of the
other two.

It can work.

(By the way, things like Kevlar really fall into the same
category as other plastics -- pretty flimsy. The only way
to make these things reasonably rigid is to use a
sandwich construction like Eton and Focal (JM Lab)).

See former comments about stiffness as the most important parameter.

Paper is significantly more articulate than plastic.

Again, all generalizations based on materials choice are false.

Although it's not as good as metal in that regard, it
also doesn't have nearly the same resonance problems that
afflict metals. The reason I didn't make this
recommendation to Audio-Dad is that hardly any mainstream
manufacturers use paper any more.

Wrong.

I couldn't think of any
paper cone + metal dome designs (for example) off the top
of my head that would be an obvious recommendation for
his application.

Seems like you're referencing a post from some other newsgroup.