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| Meetings
and other Notices |
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Meeting
Notice for November 2019
NOTE DATE AND TIME
!
Date: Tuesday,
November 19, 2019
Time: 6:30 PM
Place: The Concord
Orchestra , The Performing Arts Center,
51 Walden Street, Concord, MA 01742
Featured: Steve
Barbar, President of E-Coustic
Systems, Belmont MA
In 1978, Dr David Griesinger
developed the first commercially viable digital
reverb system which became the legendary Lexicon
224. This system and its successor, the Lexicon
480L, became (and remains) the gold standard
for audio production throughout the world.
Dr. Griesinger’s
extensive published scientific research in
room acoustics, made him an ideal candidate
to investigate the performance criteria of
electro-acoustic enhancement systems. Thus,
a research project was formed with Dr. Griesinger
investigating the physics required to make
a substantial improvement in hall acoustics,
while Muncy and Steve Barbar investigated
the requirements for transducers and system
integration. E-Coustic evolved from the science
and implementation of their research.
Steve Barbar will provide
a lecture on their system & acoustics
in the Grotto Room, located in the
basement of 51 Walden St. It will be followed
by an orchestra introduction, rehearsal, and
demonstrations of E-Coustic’s newest
room acoustical enhancement equipment in the
concert hall.
Refreshments will be available
at 6:15 PM
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Directions:
Driving from Boston – Take 93 N
or 128 N to Route MA-2 W, Concord.
On Rt. 2, proceed
for about 12 miles. Take the exit (a
sudden right turn) onto Walden St. (a.k.a.
MA-126) and continue northward 1.2 miles
to 51 Walden Street.
Parking is available.
GPS:
51 Walden St. Concord MA 01742
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The
BAS Message
November 2019 |
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1. V41N1
of the BAS Speaker has been published. It
features 2 meeting summaries: the April 2019
Recording Panel by David Hadaway, the Beolab
90 Loudspeaker by John S. Allen; and CES reports
by Kenneth Wacks.
2. Replacing
Speaker Surrounds
I’ve owned a pair
of Acoustic Research AR-9s for many years.
About 10 years ago the woofer surrounds for
one speaker rotted out. I had heard of do-it-yourself
repair, but decided to buy two new woofers.
I installed them and discarded the old drivers.
Recently one of the woofers
in the other speaker rotted. I decided to
try a kit from SimplySpeakers.com.
You get surrounds for two speakers, glue and
instructions. The instructions were good,
but I watched the recommended video on You
Tube just for reassurance. The first step
is completely removing the old surround. It
is in pieces and you have to scrape it off
the cone, then off the frame. If it is stubborn
you can use alcohol to soften it. You then
apply a bead of the glue on the edge of the
cone and spread it smoothly around with your
finger, then position the surround and start
pressing the two together, working your way
around. At first the halves don’t adhere
— it is a slow setting adhesive —
but eventually they stick together. You need
to lift the cone to get room for your fingers
to press the halves together. After an hour
of curing you do the same for the surround
attachment to the frame. Before you glue you
want to exercise the cone to make sure it
is centered and not rubbing. You can skew
it a little by the position of the surround
on the frame. You are mainly relying on the
spider to center the cone—that is usually
OK. In advanced repair the dust cap is removed
and shims are used to center the cone. Usually
that is not necessary.
At one point I had spilled
some glue on the surround so I used some alcohol
to easily remove it. Then the surround started
puckering from the alcohol! I thought I had
damaged the surround. Fortunately after it
evaporated the surround returned to normal.
After installing the woofer
everything was fine. Then a month later, rattling
sounds again—the other woofer had rotted.
So I used the 2nd surround kit and all was
good. As a test I played the Saint-Saëns
from the BAS Test CD 1 at high volume and
there were no signs of any distress.
I wish I’d saved
the first 2 woofers.
email me here
Webmaster's
Note: The
two great recone and parts companies are both
right near each other: SimplySpeakers.com
is in St. Pete and The Speaker Exchange
ReconingSpeakers.com is in Tampa. The
third, a bit smaller but still fascinating,
is SoundSpeakerRepair.com ,
in Tucson, Az. — Barry
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| Local
Area Audio News |
| Frequency
Therapeutics in Woburn announces a drug
trial for Hearing Restoration |
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| Below,
other meetings and notices which may be of interest
to BAS members |
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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...
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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 a new 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 W I N D O W
- AND FOR CONVENIENCE
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There is a posting of an ABX article, The
Digital Challenge by Stanley P. Lipshitz HERE
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