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Meetings and other Notices

Date: Sunday, April 10, 2016, 6:00 PM

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 5:30

— Webmaster's note: Those of you interested in this test and its procedures might enjoy both my white paper here: www.soundoctor.com/testcd/whitenoise.htm and also a rather fascinating discussion / demo of this pink noise phenomena by Dave Rat, on youtube, here: https://youtu.be/VHjdh-Vka-g

 

Directions: Note 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 location.

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 24.

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)

-or-

Use your GPS (!)

— Webmaster's 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.


The BAS Message
April 2016

1. BAS Speaker V38N1 has been published. It features “Spaced Coincident Recording Offers Enhanced Flexibility and Realism”by 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


Below, other meetings and notices which may be of interest to BAS members

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

Foster's Test Bench !
by Alvin Foster !    Click the logo: —>
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
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
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   
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, 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 !


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 -

AES Future Meetings
www.bostonaes.org

Acoustical Society of America
www.gbcasa.org
SMPTE New England
www.smpte-ne.org

There is a posting of an ABX article, The Digital Challenge by Stanley P. Lipshitz HERE


Classifieds
( A new section! Watch for a full page coming soon ! )
NOTE: offsite links open into a new page.
BAS Members may SELL items here; anyone may BUY.

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; dbsys22@att.biz).


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 machambers@charter.net


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 Services audiofixer@verizon.net


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, NTSTestDisc@Gmail.com.


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. dbsys22@att.biz.


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 Ampel (FAmpel@KC.RR.com).


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.

TITLE CLV / CAV? ASPECT
RATIO
Video Essentials    
Apocalypse Now CLV 2
Apollo 13 CLV 2.35
Batman (Michael Keaton) CLV 1.78
Blade Runner (Director's Cut) CAV 2.48
Blown Away CLV/CAV 2.35
Crimson Tide CLV 2.35
Daylight CLV 1.85
Evita CLV 2.35
Forbidden Planet CAV 2.35
Golden Eye CLV/CAV 2.35
The Grifters    
Highlander (10th Anniversary Director's Cut) CLV/CAV 1.82
The Hunt for Red October CLV 2.35
In The Mouth Of Madness CLV 2.35
Jurassic Park CLV 1.85
Jurassic Park CAV 1.85
Phenomenon CLV 2.35
Pocahontas CLV 1.66
Pretty Woman CLV 1.85
Raiders of the Lost Ark CLV 2.35
Raiders of the Lost Ark CAV 1.33
Star Wars: Episode 1 - A Phantom Menace    
Toy Story CLV 1.78
Who Framed Roger Rabbit CLV 1.75

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; WeinbergDJ@BostonAudioSociety.org):

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 options.
  • Panasonic RP-91D DVD player with JVB Digital regionfree mod.
  • 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 condition.
  • Garrard RC88 turntable with Shure M3D cartridge, in excellent condition.
  • Sony XM-5046 car audio amp, 4x50W into 4 Ohms

Webmaster's Corner:
Once again, for 2016 - and on through 2020 (!) here is THE useful industry calendar of audio/related events, with kudos to any and all who put this list together: www.stiernberg.com/industry-calendar

Barry

 

The Boston Audio Society
PO BOX 260211
Boston MA 02126


updated 3/27/16