[yrret]

Reading the thread about sound insulation made me remember reading about
this stuff that they've been incorporating into industrial insulation and
clothing. A very thin sheet could block sound as well a concrete wall. But
its major use is for thermal protection.

Wanted to look it up and see if its getting closer to be obtainable for a
household project. But I can't remember what its called. I think gel was
in the name. Ring a bell?

[Richard Crowley]

"yrret" wrote ...
Reading the thread about sound insulation made me remember reading about
this stuff that they've been incorporating into industrial insulation and
clothing. A very thin sheet could block sound as well a concrete wall.
But its major use is for thermal protection.

Seems unlikely. Do you have any reference for this?

[yrret]

"Richard Crowley" wrote in message
. ..
"yrret" wrote ...
Reading the thread about sound insulation made me remember reading about
this stuff that they've been incorporating into industrial insulation and
clothing. A very thin sheet could block sound as well a concrete wall.
But its major use is for thermal protection.

Seems unlikely. Do you have any reference for this?


lol, seeing as I didn't even know what it was called ya, no, I have no
reference. But thanks to the other guy giving me Aerogel I'll read up on it
and report back tomorrow. Cheers ;-)

But to be frank I do recall the articles I read mentioned the acoustic
properties as almost a footnote. They went into great detail about how well
it handles heat and mentioned sound barrier as an oh ya does that too. But
let us see what Google reveals to be the truth...

[yrret]

"yrret" wrote in message
...

"Richard Crowley" wrote in message
. ..
"yrret" wrote ...
Reading the thread about sound insulation made me remember reading about
this stuff that they've been incorporating into industrial insulation
and clothing. A very thin sheet could block sound as well a concrete
wall. But its major use is for thermal protection.

Seems unlikely. Do you have any reference for this?


lol, seeing as I didn't even know what it was called ya, no, I have no
reference. But thanks to the other guy giving me Aerogel I'll read up on
it and report back tomorrow. Cheers ;-)

But to be frank I do recall the articles I read mentioned the acoustic
properties as almost a footnote. They went into great detail about how
well it handles heat and mentioned sound barrier as an oh ya does that
too. But let us see what Google reveals to be the truth...


Interesting, if you can believe it I may have understated how amazing this
stuff really is. Doesn't seem to be available in any useful quantity at a
retail price. Still reading...

[Keith.]

"yrret" wrote in message
...

"yrret" wrote in message
...

"Richard Crowley" wrote in message
. ..
"yrret" wrote ...
Reading the thread about sound insulation made me remember reading
about this stuff that they've been incorporating into industrial
insulation and clothing. A very thin sheet could block sound as well a
concrete wall. But its major use is for thermal protection.

Seems unlikely. Do you have any reference for this?


lol, seeing as I didn't even know what it was called ya, no, I have no
reference. But thanks to the other guy giving me Aerogel I'll read up on
it and report back tomorrow. Cheers ;-)

But to be frank I do recall the articles I read mentioned the acoustic
properties as almost a footnote. They went into great detail about how
well it handles heat and mentioned sound barrier as an oh ya does that
too. But let us see what Google reveals to be the truth...


Interesting, if you can believe it I may have understated how amazing this
stuff really is. Doesn't seem to be available in any useful quantity at a
retail price. Still reading...

I remember this material being sent up in two NASA satellites,to track micro
meteorites and debris behind comets. One crashed,the other parachuted safely
and people on the web were asked to help scan the Aerogel for these bits and
tracks.
I remember there was a recipe to make it at home!

Keith.

[zero[_3_]]

"yrret" wrote in message
news
Reading the thread about sound insulation made me remember reading about
this stuff that they've been incorporating into industrial insulation and
clothing. A very thin sheet could block sound as well a concrete wall.
But its major use is for thermal protection.

Wanted to look it up and see if its getting closer to be obtainable for a
household project. But I can't remember what its called. I think gel was
in the name. Ring a bell?

Kao-wool or InsulWool?
http://thermalceramics.thomasnet.com...board-products

It's also sold in blanket form. Comes in a few different densities.
You can then apply a "ridgedizer" liquid
to make a quasi-ridged mold/form.

-zero

[Federico]

Aerogel is a silica-air matrix, the lightest material known, and it is an
extremely good insulator. However, I have never heard of any claims
whatsoever regarding sound attenuation. I really doubt it would be good at
that.

Aerogel does not provide sound attenuation
F.

[Don Pearce[_2_]]

On Wed, 14 Jan 2009 10:27:04 +0100, "Federico"
wrote:



Aerogel is a silica-air matrix, the lightest material known, and it is an
extremely good insulator. However, I have never heard of any claims
whatsoever regarding sound attenuation. I really doubt it would be good at
that.

Aerogel does not provide sound attenuation
F.


It must provide some - it is used for speaker cones.

d

[Federico]

Aerogel does not provide sound attenuation
F.


It must provide some - it is used for speaker cones.

Paper is user for speaker cones too....
Does paper provide much sound attenuation?
F.

[Don Pearce[_2_]]

On Wed, 14 Jan 2009 11:14:50 +0100, "Federico"
wrote:


Aerogel does not provide sound attenuation
F.


It must provide some - it is used for speaker cones.

Paper is user for speaker cones too....
Does paper provide much sound attenuation?
F.


Sound impermeability is an important feature, which is why cones are
used rather than flat sheets. If a speaker cone allowed, say, 99% of
sound to pass through it, that would have set a maximum possible
efficiency of 1% before all the electrical and other losses were
considered.

d

[Federico]

Aerogel does not provide sound attenuation
F.

Ok, maybe I'm wrong.....
My wife works with aerogel and she'll give me some infos about it in the
weekend.
F.

[Richard Crowley]

Don Pearce wrote ...
It must provide some - it is used for speaker cones.

Right. We all know that sound attenuation is important in a speaker cone.

[Don Pearce[_2_]]

On Wed, 14 Jan 2009 06:30:45 -0800, "Richard Crowley"
wrote:

Don Pearce wrote ...
It must provide some - it is used for speaker cones.

Right. We all know that sound attenuation is important in a speaker cone.


Vital - I hope that wasn't sarcasm...

d

[Scott Dorsey]

Richard Crowley wrote:
"yrret" wrote ...
Reading the thread about sound insulation made me remember reading about
this stuff that they've been incorporating into industrial insulation and
clothing. A very thin sheet could block sound as well a concrete wall.
But its major use is for thermal protection.

Seems unlikely. Do you have any reference for this?

The problem is that what you need for thermal protection and what you need
for blocking sound are diametrically opposed.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[GregS[_3_]]

In article , "Soundhaspriority" wrote:

Don Pearce wrote in message news:496ff85a.454033687@localhost...
On Wed, 14 Jan 2009 06:30:45 -0800, "Richard Crowley"
wrote:

Don Pearce wrote ...
It must provide some - it is used for speaker cones.

Right. We all know that sound attenuation is important in a speaker cone.


Vital - I hope that wasn't sarcasm...

d

In a specific structural configuration, yes, aerogel will prevent sound
transmission. But if an aerogel was laid out as a flat sheet, it would do
practically nothing, and neither would paper. For practical reasons, sound
absorbing materials are generally considered as substances with bulk
absorptive properties that are not strongly dependent upon specific shapes.

It was funny to read the bit about speaker cones. Its not at all important
that they have attenuation, only that they don't flex too much or resonate.

You can take almost anything and hold it in front of your ears between a pink
noise source, and there will be a noticable attenuation starting at the highest frequencies.
A piece of paper will dramatically change the sound.

[Don Pearce[_2_]]

On Wed, 14 Jan 2009 15:55:38 GMT, (GregS)
wrote:

In article , "Soundhaspriority" wrote:

Don Pearce wrote in message news:496ff85a.454033687@localhost...
On Wed, 14 Jan 2009 06:30:45 -0800, "Richard Crowley"
wrote:

Don Pearce wrote ...
It must provide some - it is used for speaker cones.

Right. We all know that sound attenuation is important in a speaker cone.


Vital - I hope that wasn't sarcasm...

d

In a specific structural configuration, yes, aerogel will prevent sound
transmission. But if an aerogel was laid out as a flat sheet, it would do
practically nothing, and neither would paper. For practical reasons, sound
absorbing materials are generally considered as substances with bulk
absorptive properties that are not strongly dependent upon specific shapes.

It was funny to read the bit about speaker cones. Its not at all important
that they have attenuation, only that they don't flex too much or resonate.

I was talking about the attenuation by stiffness, not absorption. The
cone itself will, in the unpowered state, allow plenty of sound
through. But once the amp is turned on and the short circuit of the
output stage placed across it, its movement should be determined
mostly by the electrical signal and not by air vibration. If this were
not so there would be no such thing as a sealed speaker enclosure, and
they would all need to be calculated as reflex with zero length port -
not good.

You can take almost anything and hold it in front of your ears between a pink
noise source, and there will be a noticable attenuation starting at the highest frequencies.
A piece of paper will dramatically change the sound.

Of course.

d

[Richard Crowley]

Don Pearce wrote ...
I was talking about the attenuation by stiffness, not absorption. The
cone itself will, in the unpowered state, allow plenty of sound
through. But once the amp is turned on and the short circuit of the
output stage placed across it, its movement should be determined
mostly by the electrical signal and not by air vibration.

Perhaps you should do the experiment. Clamping the voice coil so
it doesn't move (whether electromagnetically or mechanically) makes
only a slight difference in the amount of sound that will pass *through*
the cone.

OTOH, as you state, the mechanical shape of the cone (a *cone*)
makes it stiff enough to act as a piston and move the air in front of
(and behind) it as directed by the movement of the voice coil (ideally).

[fuzznuts]

In a previous existence, I was a Stills photographer. My "blimp", the
sound blocking housing for my Nikon, was made by Jacobsen Photographic
Instruments in Hollywood, and they used a material called Baryfol
(more or less the spelling), a dense lead foam in sheet form that made
the camera clicks inaudible. If this is still available, it might be
what you're looking for.
Cheers,
Jerry Wolfe
www.boskolives.wordpress.com

On Jan 13, 7:01*pm, "yrret" wrote:
Reading the thread about sound insulation made me remember reading about
this stuff that they've been incorporating into industrial insulation and
clothing. *A very thin sheet could block sound as well a concrete wall. *But
its major use is for thermal protection.

Wanted to look it up and see if its getting closer to be obtainable for a
household project. *But I can't remember what its called. *I think gel was
in the name. *Ring a bell?

[GregS[_3_]]

In article , fuzznuts wrote:
In a previous existence, I was a Stills photographer. My "blimp", the
sound blocking housing for my Nikon, was made by Jacobsen Photographic
Instruments in Hollywood, and they used a material called Baryfol
(more or less the spelling), a dense lead foam in sheet form that made
the camera clicks inaudible. If this is still available, it might be
what you're looking for.
Cheers,
Jerry Wolfe
www.boskolives.wordpress.com

I was looking around at various products on the web. The are many.
Even found leaded plexiglass. Sometimes a question of leaded or loaded.
Sometime they use other things than lead. I still have a roll of what looks like floor mat.
Small roll maybe maybe 50 foot by 20 inches. It looks innocent but try
to pick it up and you get a surprise.

greg




On Jan 13, 7:01=A0pm, "yrret" wrote:
Reading the thread about sound insulation made me remember reading about
this stuff that they've been incorporating into industrial insulation and
clothing. =A0A very thin sheet could block sound as well a concrete wall.=
=A0But
its major use is for thermal protection.

Wanted to look it up and see if its getting closer to be obtainable for a
household project. =A0But I can't remember what its called. =A0I think ge=
l was
in the name. =A0Ring a bell?

[Sigurd Stenersen]

"yrret" wrote
"yrret" wrote ...
Reading the thread about sound insulation made me remember reading about
this stuff that they've been incorporating into industrial insulation
and clothing. A very thin sheet could block sound as well a concrete
wall. But its major use is for thermal protection.

But to be frank I do recall the articles I read mentioned the acoustic
properties as almost a footnote. They went into great detail about how
well it handles heat and mentioned sound barrier as an oh ya does that
too. But let us see what Google reveals to be the truth...

Entry: sound barrier
Function: noun
Meaning: a sudden large increase in aerodynamic drag that occurs as the
speed of an aircraft approaches the speed of sound

Likely explanation: you misunderstood what you read...


Sigurd

[Ty Ford]

On Tue, 13 Jan 2009 22:01:18 -0500, yrret wrote
(in article ):

Reading the thread about sound insulation made me remember reading about
this stuff that they've been incorporating into industrial insulation and
clothing. A very thin sheet could block sound as well a concrete wall. But
its major use is for thermal protection.

Wanted to look it up and see if its getting closer to be obtainable for a
household project. But I can't remember what its called. I think gel was
in the name. Ring a bell?



monkey fur?

Regards,

Ty Ford

--Audio Equipment Reviews Audio Production Services
Acting and Voiceover Demos http://www.tyford.com
Guitar player?:http://www.youtube.com/watch?v=yWaPRHMGhGA

[Geoff]

yrret wrote:


Don't use NASA foam - it falls off and causes damage to your fuselage.

geoff

[Chris Hornbeck]

On Wed, 14 Jan 2009 21:22:06 -0500, "Soundhaspriority"
wrote:

See some he http://video.google.com/videoplay?do...59234381445258

What Ever. But the Woman In Shower suggested to the right is
pretty funny. Arf. I love having high speed Internet. It's so
intellectually uplifting.

Much thanks, as always,
Chris Hornbeck

[Chris Hornbeck]

On Wed, 14 Jan 2009 22:25:46 -0500, "Soundhaspriority"
wrote:

Chris, I'm uploading some pretty H*T aerog*ls .

Arf!

No reason why you should consider my musical taste as interesting
to you, but if you haven't heard Liz Phair's commercial debut
album _Exile in Guyville_ and get an opportunity, you might give
it a listen. Includes a song called "Girls! Girls! Girls!".

Meanest blues you'll ever hear, and from a little rich White Girl
from Chicago. Go figure.

(If you decide that you like it, bounce me back and I'll send you
her early demos and such. Drink the KoolAid!)

Much thanks, as always,
Chris Hornbeck

[Don Pearce[_2_]]

On Wed, 14 Jan 2009 21:22:06 -0500, "Soundhaspriority"
wrote:

See some he http://video.google.com/videoplay?do...59234381445258

Bob Morein
(310) 237-6511


The stiffness of aerogel can be heard in the tinkling sound. That is
what makes it such a good sound insulator.

d

[Richard Crowley]

Don Pearce wrote ...
The stiffness of aerogel can be heard in the tinkling sound. That is
what makes it such a good sound insulator.

Properties not unlike a similar-shape piece of glass (which is also
quite stiff, but not noted for being a "good sound insulator")
That video clip was not convincing IMHO.

[John Williamson]

Richard Crowley wrote:
Don Pearce wrote ...
The stiffness of aerogel can be heard in the tinkling sound. That is
what makes it such a good sound insulator.

Properties not unlike a similar-shape piece of glass (which is also
quite stiff, but not noted for being a "good sound insulator")
That video clip was not convincing IMHO.


I think that it's also an open cell foam type structure due to the
maufacturing process, so there's going to be virtually free passage of
air pressure variations across it. It may damp some of the higher
frequencies slightly, but I'd guess you'd be hard pushed to notice at
sensible thicknesses.

If I could source some, I'd try it out.

--
Tciao for Now!

John.

[Ben Bradley]

On Wed, 14 Jan 2009 09:46:09 -0800, "Richard Crowley"
wrote:

Don Pearce wrote ...
I was talking about the attenuation by stiffness, not absorption. The
cone itself will, in the unpowered state, allow plenty of sound
through. But once the amp is turned on and the short circuit of the
output stage placed across it, its movement should be determined
mostly by the electrical signal and not by air vibration.

Perhaps you should do the experiment. Clamping the voice coil so
it doesn't move (whether electromagnetically or mechanically) makes
only a slight difference in the amount of sound that will pass *through*
the cone.

OTOH, as you state, the mechanical shape of the cone (a *cone*)
makes it stiff enough to act as a piston and move the air in front of
(and behind) it as directed by the movement of the voice coil (ideally).

This is surely frequency-dependent (and dependent on the driver - I
presume we're talking about a woofer). Shorting out the voice coil
will strongly attentuate lower frequencies, but do little or no change
to the attentuation of high frequencies, which don't cause the cone to
move as a single unit.

[GregS[_3_]]

In article , wrote:
On Wed, 14 Jan 2009 09:46:09 -0800, "Richard Crowley"
wrote:

Don Pearce wrote ...
I was talking about the attenuation by stiffness, not absorption. The
cone itself will, in the unpowered state, allow plenty of sound
through. But once the amp is turned on and the short circuit of the
output stage placed across it, its movement should be determined
mostly by the electrical signal and not by air vibration.

Perhaps you should do the experiment. Clamping the voice coil so
it doesn't move (whether electromagnetically or mechanically) makes
only a slight difference in the amount of sound that will pass *through*
the cone.

OTOH, as you state, the mechanical shape of the cone (a *cone*)
makes it stiff enough to act as a piston and move the air in front of
(and behind) it as directed by the movement of the voice coil (ideally).

This is surely frequency-dependent (and dependent on the driver - I
presume we're talking about a woofer). Shorting out the voice coil
will strongly attentuate lower frequencies, but do little or no change
to the attentuation of high frequencies, which don't cause the cone to
move as a single unit.

This is true, and its true that high frequencies are vertually
non-existant comming back from the box since its supposed to be a black hole.
However, at frequencies a few multiples from the LF cutoff, sound
could come back through the cone, but that does not seem
to be a problem normally. Most of the problems occur when the enclosure
starts to vibrate.

greg

[Arny Krueger]

Don Pearce wrote in message
news:49710c4f.459143625@localhost

I was talking about the attenuation by stiffness, not
absorption.

Since both actions are in play in the real world, your comments were then
incomplete.

The cone itself will, in the unpowered state,
allow plenty of sound through.

Ditto if you short the voice coil.

But once the amp is turned
on and the short circuit of the output stage placed
across it, its movement should be determined mostly by
the electrical signal and not by air vibration.

Depends on the frequency. I know of no speakers in good working order whose
cones effectively seize up when you short their voice coil or attach a good
amp that is powered up (analogous to shorting the voice coil).

If this were not so there would be no such thing as a sealed
speaker enclosure, and they would all need to be
calculated as reflex with zero length port - not good.

The coupling between the voice coil terminals and the motion of the cone are
included in enclosure designs based on T/S parameters, for example.

You can take almost anything and hold it in front of
your ears between a pink
noise source, and there will be a noticable attenuation
starting at the highest frequencies.

Right, but rarely will a speaker driver in a large baffle stop all sound.

A piece of paper will dramatically change the sound.

But it will not attenuate all of it. At certain frequencies a piece of paper
is pretty acoustically transparent, or else we would make all of our speaker
enclosures out of 24 pound paper.

[Keith.]

"Arny Krueger" wrote in message
...
Don Pearce wrote in message
news:49710c4f.459143625@localhost

I was talking about the attenuation by stiffness, not
absorption.

Since both actions are in play in the real world, your comments were then
incomplete.

The cone itself will, in the unpowered state,
allow plenty of sound through.

Ditto if you short the voice coil.

But once the amp is turned
on and the short circuit of the output stage placed
across it, its movement should be determined mostly by
the electrical signal and not by air vibration.

Depends on the frequency. I know of no speakers in good working order
whose cones effectively seize up when you short their voice coil or attach
a good amp that is powered up (analogous to shorting the voice coil).

If this were not so there would be no such thing as a sealed
speaker enclosure, and they would all need to be
calculated as reflex with zero length port - not good.

The coupling between the voice coil terminals and the motion of the cone
are included in enclosure designs based on T/S parameters, for example.

You can take almost anything and hold it in front of
your ears between a pink
noise source, and there will be a noticable attenuation
starting at the highest frequencies.

Right, but rarely will a speaker driver in a large baffle stop all sound.

A piece of paper will dramatically change the sound.

But it will not attenuate all of it. At certain frequencies a piece of
paper is pretty acoustically transparent, or else we would make all of our
speaker enclosures out of 24 pound paper.

A dynamic speaker cone is a device with low mass so as to minimise inertia
and momentum when driven longitudinaly ,and faithfully as possible follow
the signal given by the voice coil .
It is cone shaped for rigidity and designed to restrict or stop air flow
through its structure so as to maximise the amount of forward air movement.
The fact that the cone may let sound through, is neither here nor there, its
only job is to act as a low mass air piston.

Keith.