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Date: Sunday, April 10, 2016,
Place: Boston University, Life
Science & Engineering Bldg, 24 Cummington Mall
1st Floor Conference, Room 103, Boston, MA 02215
Guest: David Griesinger
Topic: Equalization of Headphones
to Simulate Binaural Listening
I will begin with discussion of
the theory behind the procedure, about an hour. Then
participants will have a chance to try it on workstations
set up around the building You are encourage to bring
your own headphones.
The procedure: I have two small
computer monitor speakers on two stands, separated
by about 25cm.
They each play independent accurately
calibrated pink noise. A listener sits in front of
the speakers about 20cm away, with the speakers at
ear-height. The SPL of the pink noise is about 70dBA
The subject then switches to equal
loudness mode, whereby a 500Hz 1/3 octave noise band
alternates with a noise band at another 1/3 octave
frequency at a one second rate.
The subject adjusts the level
of the test band to match the loudness of the 500Hz
reference. It is helpful if the room is reasonably
quiet but it does not have to be perfectly
quiet, as the bands are at 75dB SPL. We do not test
below 200Hz. The subjects personal equal loudness
curve is continuously stored as they create it. The
subject then puts on the headphones under test, and
adjusts for the same loudness as the speaker. Once
again they perform the equal loudness tests as the
values they find are stored in another memory bank.
In this case all bands are tested, including LF. Once
the subject is satisfied they can test another pair
of headphones, up to five.
With the data collection finished,
they can switch on music of their choice if
they brought a smartphone or the like. My computer
will have binaural recordings from famous halls, which
are absolutely stunning, and very hard to turn off.
They can switch the eq on and off, or play with it
a bit if they want.
There will be refreshments at
note: Those of you interested in this test and
its procedures might enjoy both my white paper here:
and also a rather fascinating discussion / demo of
this pink noise phenomena by Dave Rat, on youtube,
that parking is no longer allowed in the block
in front of our meeting place (temp parking
for unloading/loading is OK). There is a gap
in the BU buildings on Commonwealth Ave. so
you can walk through directly to the meeting
At Boston University, Cummington
St. (Mall) is an east-west street just south
of Commonwealth Ave. It is one-way going west.
From Storrow Drive going east, take the first
BU exit. At the stop sign turn right on Commonwealth
Ave (a left is not permitted). Bear left and
at the 3rd light take a u-turn, go half a mile
and turn right on Blandford St.(Mall) (at a
traffic light) and turn right on Cummington
St. (Mall) The entrance is on your left, number
From Commonwealth Ave going
west, after Kenmore Square, after the tracks
come up out of the tunnel, there is a traffic
light at Blandford. You should turn left on
Blandford, but no left is permitted. Instead
turn right and make a U-turn. Continue on Blandford
and turn right on Cummington St. The entrance
is on your left, number 24.
MBTA Green line - exit at
Kenmore Square or the next stop, Blandford St.
& Commonwealth Ave. Walk a short distance
and make a left turn onto Blandford Mall and
then a right onto Cummington Mall.
Parking is free on Sundays
and available on Commonwealth Ave. and Beacon
St. (take a hard right at Kendall Square and
park on the bridge and take the stairs down)
and Bay State Rd (parallel to Commonwealth Ave
next to the river)
Use your GPS (!)
note: Google maps and Apple maps show them as
Blandford Mall and Cummington Mall.
Bing maps shows them as Blandford Street
and Cummington Street. YMMV.
1. BAS Speaker V38N1 has
been published. It features Spaced Coincident
Recording Offers Enhanced Flexibility and Realismby
Justus V. Verhagen, CES 2016 reports by Alvin
Foster and Nicolas Noiseux and Jim Buchanan;
Fall 2015 Asian Trade Shows by Robert Baum;
and the 2014 BAS Flea Market and Favorite Recordings
meeting by David Hadaway.
2. The Microsoft anechoic
chamber in Redmund WA has been certified by
the Guinness Book of World Records as the quietist
place on earth, -20.35 dBA. The theoretical
minimum is -23 (Brownian motion).
3. Consumer Union is leading
a crusade to end robocalls. They have a petition
that has over 200, 000 signatures. To sign up
go to endrobocalls.org
email me here
other meetings and notices which may be of interest
to BAS members
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.
has a new article here: Extracting
Numerical Data from an Excel Trend Line
Test Bench !
by Alvin Foster ! Click
the logo: >
BAS Headphone Test Article is now available
in the BASS VOLUME 25, ISSUE 4,
on Page 17, available HERE
The LIVE video podcast of our meetings,
Archived video of past meetings (only one so far!),
and Audio Podcast interviews by Alvin Foster
|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
|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
Some earlier BASS
issues, previously available only directly by mail,
are now available online, on the BAS SPEAKER page,
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,
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
The Boston Audio Society needs individuals
who will write summaries of BAS meetings into *.pages, *.doc, or *.txt
files. We usually have audio recordings of the meetings. We pay for
your work. Ask about our bonus program for meeting-writers! Contact
David B. Hadaway (603-899-5121; firstname.lastname@example.org).
For sale: Audio Precision System
1 audio test system. SYS-322A, s/n SYS1-31968, IMD, BUR, W&F options,
A-weighting filter, PCI interface card, rackmounts; asking $5000. Contact
Mark Chambers email@example.com
For sale: Several CD storage racks,
some made by Bostonwood (www.BostonWood.com/cd.html):
Two four-shelf units (25.5"Hx17"Wx5.5"D); One four-shelf
unit (25.5"Hx24"Wx5.5"D); Two three-shelf units (19.5"Hx17"Wx6.5"D);
one home-made three-shelf unit (18"Hx14"Wx6"D). I have
attached a handle and chains to several units, making them convenient
open-top carriers. David J. Weinberg (Maryland; 301-593-3230).
Seeking a two-channel preamplifier
such as an Apt Holman, an early Hafler, or an early NAD. Must work properly.
Fred Ampel (FAmpel@KC.RR.com).
Seeking prereceord Advent cassettes,
especially Russell Sherman Beethoven and Liszt recordings, and Handel's
Messiah performed by the Handel & Haydn Society under Thomas Dunn.
David R. Moran (DRMoran@aol.com).
I am disposing of all my old copies of the
BAS Speaker, which go back to 1978, more or less complete. I am going
to recycle these with waste paper unless somebody wants them for free.
I'll even pay shipping. Doug Pomeroy Audio Restoration & Mastering
Discography of Test Records. I am
compiling a list of technical test records from all recording eras and
would like to exchange information in order to confirm, expand, correct
and add entries. Send me your list and/or other information about test
records and I will send you my discography, which has nearly 200 entries
to date. I am interested in commercially released records, as well as
discs intended primarily for in-house use by audio engineers, broadcasters
and for other special applications. I am generally excluding demonstration
discs of the "Super Stereo bouncing ping-pong ball" type unless
they include at least some tracks of a technical nature, such as frequency
response and tracking tests, etc. Nicholas Starin, Portland Oregon,
Nashville AES Test CD. (www.AESNashville.org;
click the small round symbol where it says "Click here for more
info:" to download the four-page description and track list. Use
the link on the website under <Products> to send an email for
pricing and availability.) From the website: "Assembled 'by engineers,
for engineers' after a survey of the needs of a broad cross-section
of working audio pros, the disc features 71 tracks of test signals ranging
from level calibration tones, noise signals, third-octave tones, polarity
and digital meter calibration pulses, bandpassed noise and swept sinewaves.
Additional tracks include dry-recorded kick and snare drums, acoustic
guitar and piano along with spoken word and a cappella male and female
vocals. A data area on the disc features BPM charts, Excel-based calculators
and other bonus material. The CD booklet includes tutorial information
on using the test disc."
For sale: Three Denon DR-M34HR cassette
decks ($500srp) with three heads and live monitoring of the recording,
dual Dolby B/C and Dolby HX Pro circuitry. Handles normal, chrome and
metal-tape cassettes. Highly regarded in 1988. Gasparo Records used
them as duplicators. In good shape. Data at www.VintageCassette.com/denon/dr-m34hr.
$125 ea+shipping. Contact David B. Hadaway. firstname.lastname@example.org.
For sale: Arcam Solo Movie 5.1 (www.Arcam.co.uk/products,solo,Movie-Systems,SoloMovie51.htm;
$4500srp) The manual is downloadable from the Arcam website. I do not
have original packaging. $1000+shipping, which will be calculated once
destination is determined. Funds transfer or cash only; no checks. Fred
For sale. Two Tannoy HPD 315 speakers,
made in the mid-1970s, woofers might need refoaming. Steven Weiner (SDWeiner@ATT.net;
818-865-0601; Thousand Oaks, CA) is asking $500+s/h. [I have seen a
photo; the cabinets and grill look to be close to mint condition. This
ad was placed at the request of member Randy Hoffner. DJW]
Seeking: Soundfield Mark IV microphone.
Jim Mastracco (James.Mastracco@Verizon.net).
Laserdiscs for sale by David J.
Weinberg (301-593-3230; WeinbergDJ@BostonAudioSociety.org)
Four have Dolby Digital 5.1 soundtrack. Nine have DTS5.1 soundtrack.
Make offer for all or selected items.
||CLV / CAV?
|Blade Runner (Director's
Anniversary Director's Cut)
|The Hunt for Red
|In The Mouth Of
|Raiders of the Lost
|Raiders of the Lost
|Star Wars: Episode
1 - A Phantom Menace
|Who Framed Roger
Own a movie theater sound system! For sale,
top-of-the-line High Performance Stereo HPS-4000-XL screen speaker systems.
Three (left, center, right) HPS model 545-4 speaker systems (www.HPS4000.com/pages/fivefortyfive_.html)
and two HPS model 545-W subwoofer speaker systems (www.HPS4000.com/pages/545_w_.html).
All in perfect working order. The speakers are not light, but consist
of modules that can be lifted by two moderately strong men. Truck delivery
only, or come pick up. Make me an offer. David J. Weinberg (301-593-3230;
Most units come with user manuals (some also
with service manuals), remotes and cartons, as applicable. Make offer:
- ReplayTV 2020 with aftermarket larger
disk drive. Includes lifetime electronic program guide service.
- Faroudja VP400A video quadrupler. Upscales
NTSC video to 960 progressively scanned lines for a front or rear
CRT projector. Generates great image on my big screen. I don't need
it because I'm modifying my video system.
- Runco 980Ultra CRT projector (original
packing, user and service manuals).
- Vutec concave high-gain silvered screen.
8' wide, 16:9 aspect ratio, with wallmount brackets. Silvered surface
makes it appropriate for 3D projection, as the high gain overcomes
the substantial light loss caused by the various consumer 3D projection
technologies, and the curved shape can deliver a wide viewing angle
with little hotspotting.
- Lexicon DC1 surround processor, with all
- Panasonic RP-91D DVD player with JVB Digital
- Sony DVP-NS755V SACD (multichannel and
stereo), DVD, etc., progressive-scan output. $250srp.
- Tektronix D11 rackmount single-beam storage
oscilloscope with 5A15N vertical amp and 5B10N time-base/amplifier.
- Tektronix 5111 rackmount single-beam storage
oscilloscope with two 5A18 vertical amps and 5B10N time-base/amplifier.
- Teac AN-180 external dual Dolby B processor.
Simultaneous stereo record and playback.
- Pioneer CT-F4242 cassette deck, in excellent
- Garrard RC88 turntable with Shure M3D cartridge,
in excellent condition.
- Sony XM-5046 car audio amp, 4x50W into