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Meeting held June 18th, 2014 at 7:30pm Edmonds Center for the Arts, Edmonds, WA

AES PNW Section Meeting Report
Cardioid Subwoofers: Once A Miracle, Now Easily Done
with Dan Mortensen
Owner
Dansound Inc.
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PNW Committee Member and Presenter Dan Mortensen demonstrates an end-fired sub array.
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Meeting Attendees move among the subwoofer arrays to listen to low frequency response patterns.
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Dan Mortensen demonstrates use of MAPP onLine software to predict subwoofer array behavior.
Audio recordings of the meeting:
32k mp3

Photos by Gary Louie, Audio Recording by Rick Chinn


The June PNW Section meeting involved Section business/elections, then a presentation on directional subwoofer arrays by Dan Mortensen of Dansound Inc. About 27 people showed up (about 16 AES members), including Bob Moses, AES Executive Director. The venue was the Edmonds Center for the Arts theater in Edmonds, WA, north of Seattle.

Section Vice-Chair Steve Malott made opening remarks, including a reminder to vote in the AES world election. Audience members all introduced themselves, then the Section election ballot was introduced. A motion was made by Dan Mortensen to approve the entire ballot by voice vote. Seconded by Casado and others. Ayes carried, ballot passed.

The new electees for 2014-2015 are therefore:

  • Chair - Steve Malott
  • Vice Chair - Dave Tosti-Lane
  • Secretary - Gary Louie
  • Treasurer - Greg Mauser

  • Committee 2 - Mark Rogers (2 yr term)
  • Committee 4 - Lawrence Schwedler (2 yr term)
  • Committee 6 - JJ Johnston (2 yr term)
  • Committee 8 - Ivan Tashev (2 yr term)
  • Committee 10 - Rich Williams (2 yr term)

They will join the "odd-year" committee members who have one year remaining in their 2 year terms:

  • Committee 1 - Bob Smith
  • Committee 3 - vacated by Scott Mehrens
  • Committee 5 - Daniel Casado
  • Committee 7 - Dan Mortensen
  • Committee 9 - Dr. Michael Matesky

And Membership Promoter Aurika Hays and Member-at-large Rick Chinn.

Dan Mortensen, owner of Dansound Inc. and PNW Section committee member, told of the modern implementations of directional subwoofer systems, and how various configurations of boxes can be made directional in certain ways.

Instead of the common wisdom that lows are omnidirectional, they can be made directional for purposes such as noise ordinance compliance, reduced stage wash or reflections. His research utilized the free online Meyer Sound Labs MAPP speaker prediction calculator. He described and showed MAPP charts of directional subs configurations such as cardioid, end-fire, Rat Sound Vortex, and others, in several different simulated situations such as on a hard concrete floor or elevated 100 feet high. There are quite a few configurations of custom configured boxes in use by sound companies.

After a refreshment break, door prizes awarded were:

  • AES USB memory sticks (from AES/Bob Moses): Jayney Wallick, Chris Deckard
  • DVD of AES-PNW meeting with the late Frank Laico: Bob Moses, Tyler Hovatter
  • Book, Musical Acoustics by Arthur Benade (courtesy Uneeda Audio): Dave Ellis

Continuing after the intermission, Section committee members Bob Smith and Daniel Casado assisted Dan with live demos and SMAART measurements of some configurations on the stage. Attendees could walk around the subs and confirm or deny the directionality and the measurement results. Audience member Ryan McCauley added many additional useful comments based on his work at McCauley Sound.

A special thanks goes to TJ Loehman of the ECA.


Reported by Gary Louie, PNW Section Secretary


Last Modified 7/18/2015 16:20:30 (dtl)