What's new? 

• 8/31/10 
  The Burning Amp Festival - Wood Artistry will demo ORION-3.2 and I will give a talk: 
  "What Are the On-axis and Off-axis Frequency Response Requirements for Stereo Loudspeakers?"
  
  
• 8/31/10
  2010 Rocky Mountain Audio Fest - Linkwitz Lab, Wood Artistry and Seas will demo ORION-3.2 in room 414
  
  
• 8/31/10 
  Links - Some factors in loudspeaker quality (1976, Harwood, BBC R&D)
  
  
• 8/23/10
  ORION-3.2 - A new loudspeaker with a proud heritage
   
  
• 8/11/10
  Linear Audio - A new semi-annual publication. I contributed an article to the first issue of the 'bookzine'.
  
  
• 7/31/10
  Issues in speaker design - L-07 Dipole loudspeaker
  
  
• 7/28/10
  Issues in speaker design - High -frequency down-shelving for ORION-3
  
  
• 7/28/10
  Issues in speaker design - What is the optimum polar response for a loudspeaker?
  
  
• 7/26/10
  ORION-3 - Revision 3 of the ORION loudspeakers
  
  
• 6/25/10
  PLUTO+ subwoofer - New closed-box1.xls spreadsheet with driver data base
  
  
• 6/20/10
  Links - Vector Waveform Format
  
  
• 6/9/10
  Links - Acoustics Handbook
  
  
• 6/9/10
  Other designs - Horbach-Keele linear-phase digital crossover filters (updated)
  
  
• 6/3/10
  ORION Challenge - Words from a satisfied customer
  
  
• 5/31/10
  Digital Photo Processes - A pocketable companion for my LX3 
  
  
• 5/24/10
  Links - Putting the Science back into Loudspeakers
  
  
• 4/24/10
  Publications - STEREO - From live to recorded and reproduced - What does it take?
  
  
• 4/21/10
  Links - Constant beamwidth transducer (CBT)
  
  
• 4/21/10
  Other designs - Controlled directivity loudspeaker designs
  
  
• 3/31/10
  Issues in speaker design - Accuracy, spatial distortion and plausibility of the auditory scene - Conclusions
  
  
• 3/9/10
  Links - Microphones and acoustic measurements
  
  
• 3/1/10
  Issues in speaker design - Triggered burst measurements of tweeters
  
  
• 2/28/10
  PLUTO omni speaker - The assembled and tested electronics module is available again
  
  
• 2/4/10
  Links - The physics and psychoacoustics of surround recording
  
  
• 2/1/10
  Links - Multichannel natural music recording based on psychoacoustic principles
  
  
• 1/28/10
  Links - Perceptual differences between wavefield synthesis and stereophony
  
  
• 1/16/10 
  Links - A Case for Subjectivity
  
  
• 1/13/10
  Links - The Seductive (Yet Destructive) Appeal of Loud Music
  
  
• 1/13/10
  Issues in speaker design - Spatial distortion in audio
  
  
• 12/29/09
  Accurate Stereo - Accurate performance of a stereo sound system
  
  
• 12/16/09
  Active filters - Room EQ
  
  
• 12/4/09
  Toneburst CD - Pink Noise Imaging Test 
  
  
• 11/13/09
  Publications - Slides of two talks at the 7º Conferencia AES Chile, November 2009
  
  
• 10/19/09
  Design of loudspeakers - Burning Amp Festival, October 2009
  
  
• 10/16/09
  Sound reproduction - The best sound reproduction ...
  
  
• 10/16/09
  Crossovers - The best crossovers ...
  
  
• 10/16/09
  Loudspeakers - The best loudspeakers ...
  
  
• 10/15/09
  Room acoustics - The best rooms ...
  
  
• 10/14/09
  Publications - Slide presentation and soundtrack from "The challenge to find the optimum radiation pattern and placement of stereo loudspeakers in a room for the creation of phantom sources and simultaneous masking of real sources" - AES New York, October 2009
  
  
• 10/14/09 
  Publications - Manuscripts from "Recording and reproduction over two loudspeakers as heard live" - AES Munich, May 2009
  
  
• 8/16/09
  Publications - "Electrical, mechanical and acoustic filters in the design of a loudspeaker with dipole woofers"
  
  
• 7/17/09
  Publications - "Investigation of sound quality differences between monopolar and dipolar woofers in small rooms", 1998
  
  
• 7/17/09
  Publications - "Development of a compact dipole loudspeaker", 1992
  
  
• 7/15/09
  Links - Audio Musings by Sean Olive
  
  
• 7/15/09
  Links - Enjoy the Music - Review Magazine
  
  
• 6/20/09
  Digital Photo Processes - LX3 in use
  
  
• 6/12/09
  Issues in speaker design - Crossover topology mistakes
  
  
• 5/27/09
  Links - A sensibly designed loudspeaker, the GRIMM AUDIO LS1
  
  
• 5/21/09 
  Publications - Recording and reproduction over two loudspeakers as heard live - AES Munich, May 2009
  
  
• 5/21/09
  Links - Review of the Audio Artistry VIVALDI open-baffle loudspeaker from 1996
  
  
• 4/9/09
  PLUTO supplies - Assembled, tested, and ready to play PLUTO-2.1 Electronics Modules are available again.
  
  
• 4/2/09
  Active Filters - Passive versions of filters 5, 6, and a fixed attenuator 10
  
  
• 3/23/09
  ORION  FAQ - When do I need THOR subwoofers?
  
  
• 1/15/09
  PLUTO-2.1 - The latest update of PLUTO
  
  
• 12/6/08
  Links - The "Stereo Dipole"
  
  
• 12/6/08
  Links - Monte Kay's Home Theater
  
  
• 12/6/08
  Links - Horbach-Keele digital crossovers
  
  
• 12/3/08
  Digital Photo Processes - Waiting is over! The compact LX3 camera
  
  
• 11/12/08 
  Pluto-2 - A loudspeaker review by Peter Aczel of The Audio Critic
  
  
• 10/30/08
  FAQ 20 - What contributes to the polar response of ORION+?
  
  
• 10/22/08
  Design of loudspeakers - AES Convention, RMAF, Burning Amp
  
  
• 10/21/08
  Design of loudspeakers - First correspondence between SL and Laurie Fincham from KEF
  
  
• 10/20/08
  Publications - "Phantom images in 2-channel audio playback versus natural hearing processes"
  
  
• 8/22/08
  Pluto-2 owners check your Support Page for the latest update.
  
  
• 8/16/08
  Rocky Mountain Audio Fest - First public demonstrations of the ORION+ and Pluto-2.
  
  
• 8/16/08
  The Burning Amp Festival - I will give a talk about "The path to increased realism in 2-channel audio playback and recording"
  
  
• 8/4/08
  Links - Floyd Toole: Sound Reproduction - Loudspeakers and Rooms
  
  
• 7/20/08
  PLUTO-2 - Tweeter level adjustment
  
  
• 6/18/08
  Recording for stereo - Stereo recording angles
  
  
• 6/17/08
  Recording for stereo - Mapping from recording to playback
  
  
• 5/30/08
  Pluto-3 - A 3-way speaker with external crossover/equalizer and power amplifiers for someone who likes to test their skills.
  
  
• 5/30/08
  Pluto-2 - Construction details for conversion from PLUTO to Pluto-2 and to Pluto-2+
  
  
• 5/23/08
  ORION++ - Rear tweeter level adjustment
  
  
• 5/19/08
  Pluto-2 -  A number of revisions to the original PLUTO for an easier to build and extended bass output 2-way system.
  
  
• 5/7/08
  Publication #24 - "Accurate sound reproduction from two loudspeakers in a living room"
  San Francisco AES Section Meeting. Presentation slides.
  
  
• 5/4/08
  Added Reference [5] for further reading about Investigation of energy storage.
  
  
• 4/26/08
  Added Tracks 19-28 to the Toneburst CD
  
  
• 4/23/08
  Added web page about Recording for stereo practices
  
  
• 4/16/08
  See the AES Convention paper which underlies the Room optimized stereophonic reproduction web page.
  
  
• 4/4/08
  The first open baffle loudspeaker?
  
  
• 4/3/08
  Audio CD with demonstrations of Auditory Scene Analysis
  
  
• 4/3/08
  H-frame loudspeaker from before 1936
  
  
• 3/30/08
  Review of the ORION++ by The Audio Critic
  
  
• 3/28/08
  A student version of CircuitMaker circuit analysis software is still available for download.
  
   
• 3/28/08
  Software signal generator for download.
  
  
• 3/26/08
  PLUTO owners check their support site for the Seas L16RN-SL circuit changes.
  

• 3/21/08
  Summarizing statement added to the Home page.
  
  
• 3/12/08
  A little homage to special friends:  Russ Riley,   Lyman Miller,   Brian Elliott
  
  
• 3/10/08
  Added an Analog to digital conversion page to Digital Photo Processes. 
  
  
• 2/29/08
  Added a Sharpness page to my camera investigation.
  
  
• 2/25/08
  Added photos from my Audio Artistry era to the Links page.
  
  
• 2/22/08
  I added an addendum to Suggestions and hearing.
  
  
• 2/20/08
  I am posting the Digital Photo Processes pages. This will highlight my limited bandwidth issues and probably force me into a more costly hosting plan. But then there is always the Website CD.
  
  
• 2/15/08
  A 1999 paper by B. Moore that deals with "Controversies and mysteries in spatial hearing" came to my attention again. I had forgotten about it. It would have helped me to understand the reason for the surprising similarity between an omni and a dipole in a reverberant room right away.
  
  
• 2/13/08
  It is likely that the website will be down on the 21st day of each month due to heavy traffic, but it will always resume on the 22nd when my 50 GB/mo bandwidth allowance period starts up again. 
  
  
• 1/1/08
  I added the "cocktail party effect" to the paragraph about "Sound stream segregation" on the "Recording for stereo" page. Some readers were apparently confused about what Don is trying to accomplish.
  
  
• 12/22/07
  In case you wondered why the website was shut down yesterday for several hours, I had reached my monthly bandwidth allowance of 50 Gigabyte. Today starts a new monthly pay period with my ISP. If you own the Website CD, then you have access to 99% of the information here at all times and you probably will not notice any future interruption. 
  
  
• 12/20/07-3
  The UK Chapter of the Audio Engineering Society keeps a full record of monthly talks on its website. The great variety of audio related subjects is educational and interesting.
  
  
• 12/20/07-2
  I receive about 300 email messages per day. 98% of that is junk and I just pull out those that have a relevant subject line. So be clear with the subject if you want to get through my Spam filter. Before writing please read my CAUTION.
  
  
• 12/20/07-1
  The Orion User Group is a good place to ask questions, get help and make contact. It also applies to PLUTO. 
  
  
• 12/19/07-2
  If you are thinking of designing a box loudspeaker, then read Loudspeaker System Design. It covers many fundamental issues.
  
  
• 12/19/07-1
  A reminder to those who have bought documentation from LINKWITZ LAB. On the cover is the URL for a support page. Check it for the latest updates.
  
  
• 12/18/07-2
  My recent talk in London gives a summary of what has been learned here about loudspeaker design for accurate sound reproduction in relatively small rooms. ORION+ and PLUTO+ embody the key features that a loudspeaker must have. I hope that these prototypes will stimulate eventually some new loudspeaker developments for the high-end audio market so that a wider audience can hear what a simple 2-channel sound system is capable of. I am not holding my breath, though. The industry, its marketers and commentators are firmly locked into vented boxes and no fresh air comes in. Besides, the profit in this business is in cables, spikes, room tuning, etc. and now compact speakers for the iPod generation, but their hearing might be already damaged.
   
• 12/18/07-1
  The first and last links in the left hand column should let you find quickly what is new on the website by pointing to this page. This new page also gives me a convenient place to add timely comments.