7 Mar
2019
7 Mar
'19
8:49 p.m.
https://www.sciencedaily.com/releases/2019/03/190307103109.htm
Might make managing sound a bit easier in studios?
--
David W. Jones
gnome(a)hawaii.rr.com
authenticity, honesty, community
http://dancingtreefrog.com
Sent from my Android device with F/LOSS K-9 Mail.
7 Mar
7 Mar
9:23 p.m.
On Thursday 07 March 2019, David W. Jones wrote:
https://www.sciencedaily.com/releases/2019/03/190307103109.htm
Might make managing sound a bit easier in studios?
April 1st seems to be very early this year?!
Before I have seen transmission or insertion loss measurements over frequency I
do not believe it. For sure you can tune such a system to be efficient in a
small frequency range. The paper cost money unfortunately.
Gerhard
10:58 p.m.
On Thu, March 7, 2019 2:23 pm, Gerhard Zintel wrote:
For sure you can tune such a system to be efficient
in
a small frequency range.
The article mentioned "a" high pitched tone, singular article in English
implying single frequency or small spread of frequency. Does not seem
likely to be useful for music use, might help for machinery with a
specific annoying high pitch frequency.
--
Chris Caudle
8 Mar
8 Mar
6:50 a.m.
On Thu, 7 Mar 2019 15:57:56 -0600, Chris Caudle wrote:
On Thu, March 7, 2019 2:23 pm, Gerhard Zintel wrote:
Not for music, a "valuable" use case is provided by this article.
On Thu, 7 Mar 2019 21:23:31 +0100, Gerhard Zintel wrote:
For sure you can tune such a system to be
efficient in
a small frequency range.
The article mentioned "a" high pitched tone, singular article in
English implying single frequency or small spread of frequency. Does
not seem likely to be useful for music use, might help for machinery
with a specific annoying high pitch frequency. April 1st seems to be very early this year?!
This was my first thought, too.
Today is International Women's Day. I hope quoting a women isn't sexist.
"Drones are a very hot topic," Zhang says. Companies like Amazon are
interested in using drones to deliver goods, she says, and "people are
complaining about the potential noise."
9:10 a.m.
On 3/7/19 7:47 PM, audio(a)fn.de wrote:
On Thu, 7 Mar 2019 15:57:56 -0600, Chris Caudle
wrote:
It's also the first creation of such a thing. Possibly with further
research and development, the frequency spread can be broadened. I think
they could also be layered, with different layers controlling different
frequency bands.
--
David W. Jones
gnome(a)hawaii.rr.com
authenticity, honesty, community
http://dancingtreefrog.com
On Thu, March 7, 2019 2:23 pm, Gerhard Zintel
wrote:
Not for music, a "valuable" use case is provided by this article. For sure you can tune such a system to be
efficient in
a small frequency range.
The article mentioned "a" high pitched tone, singular article in
English implying single frequency or small spread of frequency. Does
not seem likely to be useful for music use, might help for machinery
with a specific annoying high pitch frequency.
9:45 a.m.
On Thu, 7 Mar 2019 22:10:17 -1000, david wrote:
It's also the first creation of such a thing.
That is a fair point.
Anyway, serious scholars at least should provide a working environment,
even if it should be shit, such as an Amazone drone. Nowadays way to
many academics (independent of the gender) blow up daring fantasias.
Just yesterday I turned off a television production. Several
researchers (including the murderer of Pluto) talked about a new 9th
planet. I couldn't stand those far-fetched claims (lies), such as the
new 9th planet might be a super-Earth, with possible moons, where life
forms might exist. It's fair to be a dreamer, but unfair to lie, just
to get money from less intelligent people, for less relevant research,
than the research we really need regarding damage limitation/to
hopefully fix all the lies from the past. Before we use new plastic
equipment for noise reduction of Amazone drones delivering pumps, we
should consider to tidy the Pacific trash vortexes.
Just my 2 Cents
10:27 p.m.
Mail didn't went through to mailing list, 2nd trial:
(sorry Chris to have sent it to your private mail address accidentally)
On Thursday 07 March 2019, Chris Caudle wrote:
Now that I looked closer to the picture of the device I assume I understand the
principle. Nothing new, used in e.g. thousands of exhaust systems for 50 years
and more.
Split a pipe into two pipes with equivalent sections (same area in both
downstream pipes). Make pipe 2 longer than pipe 1. Let both pipes join together
at an outlet orifice and radiate into the open.
The difference in length between the pipes is L. At the frequencies where L is
half a wavelength the both waves at the opening are out of phase. This gives
(ideally) total reflection at the opening.
The picture gives the impression of about a few centimetres difference between
outer path (the spiral inside the plug) and the direct path (length of the
plug). The first efficient reduction is to be expected at
f = C / (2*L)
thus about 5 kHz for L = 3.4 cm. It is efficient furthermore at multiples of
that frequency.
From the article
"If, however, you peered into the PVC pipe, you would see the loudspeaker's
subwoofers thrumming away."
At 5 kHz you will never see the speaker thrumming! It is written as if they
could cancel not only the "high-pitched note" but also the low end. That is
obviously due to the writers lack of knowledge or pure advertisement bullshit.
just my 2 cent
Gerhard
For sure you
can tune such a system to be efficient in
a small frequency range.
The article mentioned "a" high pitched tone, singular article in English
implying single frequency or small spread of frequency. Does not seem
likely to be useful for music use, might help for machinery with a
specific annoying high pitch frequency. 
7:53 p.m.
Dear David,
Am 07.03.19 um 20:49 schrieb David W. Jones:
https://www.sciencedaily.com/releases/2019/03/190307103109.htm
Might make managing sound a bit easier in studios?
I took a short look at the cited publication, Phys. Rev. B99, 024302.
While the device is surely interesting, it won't help you in studios.
You can put the ring on a tube to block a small frequency window.
The device is based on on Fano-resonance and is there relatively narrow.
In the publication the centre frequency of the near perfect damping
is ~ 460Hz, and a width of ~20 Hz (estimated from the figure).
So this might be interesting to filter noise from an air-conditioning,
which may make managing sound a bit easier during a hot summer,
otherwise it won't help much.
Best regards,
Peter
11:23 p.m.
On March 8, 2019 8:53:21 AM HST, Peter <list(a)schmitteckert.com> wrote:
Dear David,
Am 07.03.19 um 20:49 schrieb David W. Jones:
Thanks, I was visualizing it as a sheet of material you could just hang like a curtain. I
think the damping frequency can be changed for different versions of the material?
--
David W. Jones
gnome(a)hawaii.rr.com
authenticity, honesty, community
http://dancingtreefrog.com
Sent from my Android device with F/LOSS K-9 Mail.
https://www.sciencedaily.com/releases/2019/03/190307103109.htm
Might make managing sound a bit easier in studios?
I took a short look at the cited publication, Phys. Rev. B99, 024302.
While the device is surely interesting, it won't help you in studios.
You can put the ring on a tube to block a small frequency window.
The device is based on on Fano-resonance and is there relatively
narrow.
In the publication the centre frequency of the near perfect damping
is ~ 460Hz, and a width of ~20 Hz (estimated from the figure).
So this might be interesting to filter noise from an air-conditioning,
which may make managing sound a bit easier during a hot summer,
otherwise it won't help much.
Best regards,
Peter
9 Mar
9 Mar
9 a.m.
Dear
Am 08.03.19 um 23:17 schrieb David W. Jones:
Thanks, I was visualizing it as a sheet of material
you could just hang like a curtain. I think the damping frequency can be changed for
different versions of the material?
Yes you could, and you could could put several on a tube. However, this
device is explicitly build to be open in the sense that air can flow through
it. For a curtain like device you can build standard meta-materials,
see e.g. wikipedia for an explanation. While meta-materials are typically
build for electro-magnetic waves, the principle does work for sound waves.
The main problem is, you need sub wave-length structures where the total size is
than a few wave lengths, which makes it unfeasible for low frequencies in a studio,
as the curtain needs a 'considerable' thickness.
Nevertheless you could build band gap material blocking sound in a frequency range,
much larger than that of the ring, which is a special purpose device.
A more typical feature would be blocking the EM wave with the frequency of a few
GHz, block the Wifi and the let the light through. And the most funny application
is the invisibility-cloak with which you can hide things so small you wouldn't be
able to see without the invisibility cloak. But but works, just too expensive to build
on a macroscopic scale.
Best regards,
Peter
8 Mar
8 Mar
8:46 p.m.
On 3/7/19 8:49 PM, David W. Jones wrote:
https://www.sciencedaily.com/releases/2019/03/190307103109.htm
Might make managing sound a bit easier in studios?
If your biggest worry is annoying the neighbours with your studio
exhaust pipe, then definitely yes.
--
Jörn Nettingsmeier
Tuinbouwstraat 180, 1097 ZB Amsterdam, Nederland
Tel. +49 177 7937487
Meister für Veranstaltungstechnik (Bühne/Studio), Tonmeister VDT
http://stackingdwarves.net
8:55 p.m.
On 3/8/19 8:46 PM, Jörn Nettingsmeier wrote:
On 3/7/19 8:49 PM, David W. Jones wrote:
Jokes aside, I'm trying to wrap my head around this one:
"By comparing sound levels with and without the metamaterial fastened in
place, the team found that they could silence nearly all -- 94 percent
to be exact -- of the noise, making the sounds emanating from the
loudspeaker imperceptible to the human ear."
Let's assume that percentage refers to sound pressure level, not
spectral width. Is it reasonable to expect something like 24dB damping
in a narrow band? That would be really nice, but not amazing.
Yet, if it's a high pitched noise they're battling, that probably
translates to "still very annoying".
Those evil log scales, here's why the press likes percentages better.
Unfortunately, our senses don't care.
--
Jörn Nettingsmeier
Tuinbouwstraat 180, 1097 ZB Amsterdam, Nederland
Tel. +49 177 7937487
Meister für Veranstaltungstechnik (Bühne/Studio), Tonmeister VDT
http://stackingdwarves.net
https://www.sciencedaily.com/releases/2019/03/190307103109.htm
Might make managing sound a bit easier in studios?
If your biggest worry is annoying the neighbours with your studio
exhaust pipe, then definitely yes.
9:26 p.m.
Dear Jörn,
Am 08.03.19 um 20:55 schrieb Jörn Nettingsmeier:
Let's assume that percentage refers to sound
pressure level, not spectral width. Is it reasonable to expect something like 24dB damping
in a narrow band? That would be really nice, but not amazing.
Actually, in the figure of the corresponding publication the have a peak damping of
~13dB.
The frequency range with a damping >10db appears to be of the order of 1Hz.
For me, the only interesting aspect of the device is, that it is pretty open.
Yet, if it's a high pitched noise they're
battling, that probably translates to "still very annoying".
Provided you are annoyed by a fair-play noise which doesn't change its tune.
Those evil log scales, here's why the press likes
percentages better. Unfortunately, our senses don't care.
I can only agree. I'm saying for years that Logs are all evil, especially those with
complex arguments.
Best regards,
Peter
2126
days inactive
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12 comments
7 participants
participants (7)
-
audio＠fn.de -
Chris Caudle -
david -
David W. Jones
-
Gerhard Zintel -
Jörn Nettingsmeier -
Peter