| Meetings
and other Notices |
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November
2022
Online
Meeting Notice
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Date: Saturday, November
19, 2022, 2:00 PM
Place: ZOOM On-line
Guests: Alvin Foster,
Secretary & Nick Noiseux, President of
the Boston Audio Society
Topic: Reports on the
2022, 153rd AES Convention in NYC
The Audio Engineering
Society’s (AES) New York 2022 Convention
was held at the Jacob Javits Center. It ran
for about a week: October 19-27. The open
and free exhibit days were 19-20. Nick Noiseux
and Alvin Foster traveled to the Convention
to interview many exhibitors connected to
our audio-video hobby.
The Convention Hall
includes multiple rooms for seminars, research,
and presentations. The exhibit floor space
is about the size of a football field. On
display are equipment and software to enhance
professional audio-video users. The NAB show
was held at the same time in the other half
of the hall.
Alvin and Nick conducted
several interviews with manufacturers whose
products match our BAS interests. The interviews
included virtual reality (VR) and compatible
microphones. This Saturday’s, 45-minute
video-interview was with Svein Berge, CEO
of Harpex
Audio and the maker of the brand new,
84-capsule SpcMic. The near ping pong shaped
paddle includes 84-MEMS capsules.
What is a MEMS microphone?
A MEMS (Micro Electro Mechanical Systems)
mic is a pressure-sensitive diaphragm etched
into a silicon wafer via MEMS processing.
MEMS mics are largely based on electret capsules
and the SpcMic has onboard preamps and analog-to-digital
converters. MEMS mics are also known as mic
chips or silicon mics.
SpcMic’s almost
triangular shaped paddle is flat, defying
the typical spherical form adopted by others
seeking higher order Ambisonics. During our
interview, Svein made the case for the unusual
structure and size of his $2400 High order
Ambisonic microphone. www.spcmic.com
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Join
the Zoom Meeting !
If you are using a computer
and this is your first time with Zoom, please
give yourself at least 15-20 minutes
prior to the meeting to set things up:
click on the link in the Zoom instructions
below and you will be guided to download
the Zoom software, HERE: https://zoom.us/download
You can use your computer’s
audio if you have a headset attached, or you
can dial-in for audio. If you have a smart
phone or tablet and a good internet connection,
then you should install the Zoom app for your
device and connect using it.
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THE
BAS MESSAGE
November 2022 |
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Moths and Bats
Bats and moths have
been involved in an acoustic arms race between
predator and prey ever since bats evolved
echolocation some 65 million years ago.
Researchers found that
moth wings proved to be excellent sound absorbers,
even when on top of an acoustical solid substrate,
with the wings absorbing as much as 87% of
the incoming sound energy. The effect is also
broadband and omnidirectional, covering a
wide range of frequencies and sound incident
angles.
"What is even more
impressive is that the wings are doing this
whilst being incredibly thin, with the scale
layer being only 1/50th of the thickness of
the wavelength of the sound that they are
absorbing," explained lead author Dr.
Thomas Neil. "This extraordinary performance
qualifies the moth wing as a natural occurring
acoustic absorbing metasurface, a material
that has unique properties and capabilities,
that are not possible to create using conventional
materials."
https://phys.org/news/2022-06-moth-winginspired-absorbing-wallpaper-sight.html
email me here
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WEBMASTER'S
NOTE:
But before you go batty trying to catch a moth,
don't forget our very own master acoustics reference
page here:
https://www.bostonaudiosociety.org/links3.htm
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Below,
other meetings and notices which
may be of interest to BAS members |
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MAHLER
3
In the recent
(April 2022) performance of Mahler’s Third
Symphony at Boston's Symphony Hall by Ben Zander
and his Boston Philharmonic, the recording was done
with the three main spaced omnis with two more farther
back. No accent mikes or chorus microphones were
used nor, it turns out, were they needed. Remarkably,
this produced a recording that is as close to the
Symphony Hall experience as may be possible.
The info is
here: www.bostonphil.org/concerts/2021-2022/bpo4-mahler3
Here is the
recording in its entirety as a single .WAV file;
44k / 16 bit; 1hr 47 min
Mahler
Sym 3 CD.wav 1.1GB
(For those of you with editing software note that
the .wav file HAS markers to denote the movements.)
Here is the
exact same Symphony 3 with the movements separated
as FLAC files, 48k / 24 bit as a ZIPped file:
Mahler
3 Zander as FLAC.zip 1GB
IF you'd like
further Gustav Mahler info... https://en.wikipedia.org/wiki/Gustav_Mahler
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Shop
Talk
Shop Talk was
a WBUR program about Hi Fidelity, music, speakers,
tape recorders, etc. Enjoyed by many during the
1970s, the program's format was ‘talk’
and interviewing major audio luminaries. It was
a forerunner of the popular program Car Talk!
Peter Mitchell and Dr. Richard
Goldwater were the original hosts. They were later
joined by Brad Meyer. Here, John Allen interviews
Scott Kent:
Shop
Talk John Allen talks to Scott Kent on SPEAKERS.mp3
(81Mb 1:27)
Shop
Talk John Allen talks to Scott Kent on TAPE RECORDERS.mp3
(79Mb 1:26)
There is also an episode track
on the BAS
CD and here is that Description:
Track 12. "Shop Talk",
WHRB-FM, November 5, 1984.
Peter Mitchell (on the left), Richard Goldwater,
MD (center) and E. Brad Meyer (right) introduce
the show with a 1932 stereo recording and prepare
to talk with guests Mark Davis and David Moran,
both then of dbx corporation.
Shop Talk, which through most
of its ten-year life on WBUR featured just Mitchell
and Goldwater, was the precursor of Tom and Ray
Magliozzi's "Car Talk". As we finished
our 9:00-10:30 stint every Saturday morning, Tom
and Ray would take our places and begin joking
with each other. Eventually the station manager
figured out that they were funnier than we were,
and that more people drove cars than owned hi-fi
equipment, and fired us. Until then, the show
publicized the Boston Audio Society, vastly increasing
attendance at our monthly meetings. The show came
back for a time during the '80's on the Harvard
station WHRB, where we appeared once a month as
guests of HRB stalwart David Elliott. [EBM]
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| BAS
MICROPHONE CLINIC REPORT ! |
| In September 2009
the B A S held a microphone clinic, testing 37 different
microphone models. The ambitious nature of the clinic
effort, the extent of data collection, the number
of individuals involved in microphone testing and
in writing various sections of the report, and the
complexity in determining how to construct the clinic
report and make it available to members resulted it
not being published until now. The dataset is extensive.
Representative samples were
included in the abbreviated report in "The
B A S Speaker"
(Fall 2015; v37n3)
Go to the MICROPHONE
CLINIC PAGE for more...
...and don't
forget, here is the master
list of microphones in the world
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When collecting
and plotting "noisy" data
it is often useful to have Microsoft
Excel plot a Trend Line through it.
If that data is to be used for
further work, it may be necessary to
have an X-Y table of the Trend Line.
That is not easy to get and this paper
will show how to do it.
Joseph DeMarinis
has an article here: Extracting
Numerical Data from an Excel Trend Line
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Foster's
Test Bench !
by Alvin Foster ! Click
the logo: —> |
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The rapidly-becoming-famous
BAS Headphone Test Article is
now available in the BASS VOLUME
25, ISSUE 4, on Page 17, available
HERE
PDF 3mb |
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Visit
our PODCAST PAGE
for:
The LIVE video podcast of our meetings,
Archived video of past meetings (only
one so far!),
and Audio Podcast interviews by Alvin
Foster |
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There is a supplemental
and further explanation addendum paper to the
E. Brad Meyer / David Moran paper published
in the September, 2007 issue of the AES
Journal. That page, which documents
the experimental protocol and audio systems/source
material is here:
www.bostonaudiosociety.org/explanation.htm
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| There
is a Power Point Presentation of the lecture
given by Dr. Barry Blesser at the March 2007
Meeting. The Meeting page synopsis is HERE;
the Power Point Presentation (as a web page)
is HERE |
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Some earlier
BASS issues, previously available only
directly by mail, are now available online,
on the BAS SPEAKER page, HERE
Show your
appreciation for the immense amount of dedicated
work that went into both the original writing,
gathering, editing and printing, PLUS
the more recent scanning and conversion to
PDF format, by joining the Society, HERE
!
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A
L L O F F S I T E L I N K S O
P E N I N T O A N
E W T A B O R W I N D O W
- AND FOR CONVENIENCE
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