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| Challenge | Requirements | Supplies | Promotion | Subwoofer | Photos | Reviews | ASP | FAQ | Revision 0.1 | Revision 2ORION-3 | ORION-4 |


The challenge  
to build a state-of-the-art loudspeaker yourself

+++  Build this unique loudspeaker yourself or let us build it for you  +++

My experience with the Beethoven series, the Vivaldi, and PHOENIX, has led to a new design, which captures the essential sonic features of those speakers, except in a smaller package, one that would be more acceptable in many domestic situations. I named the loudspeaker


It should be understood that engineering is about trade-offs. In this case I have given up some maximum volume capability below 40 Hz, that may be required for a few music recordings when played at very high levels, while maintaining an extended frequency range down to 20 Hz and gradual 2nd order roll-off below it. In return I have a speaker with seamless integration over the whole frequency range, with impactfull dynamics, a speaker that sets up a wide, tall and deep sound stage, yet with pin point localization of instruments and voices, with speed and warmth. All this, of course, only for well recorded material. The speakers disappear and what remains is the panorama of sound and the experience of music. I am very pleased with the accuracy and balance of sonic attributes that this speaker achieves. Combined with its relatively small size and its looks it represents to me an ultimate speaker, one that I could live with for a long time, because it provides such a satisfying musical illusion and experience. 

The ORION design manifests to me what Saint-Exupéry mused about when he described his airplane in "Night Flight" and wrote something like: "A machine is not perfect when you cannot add anything more to it, but when you cannot remove anything without destroying its function." Thus the appearance of the ORION also exemplifies the Bauhaus motto: "Form follows function".

I sell detailed construction plans, blank printed circuit boards and a CD with test signals. You can also order the fully assembled and tested electronics, a flatpack of precut wooden parts or partially assembled cabinets and even wiring harnesses to hook up the drivers. This leaves to you the the pieces that you feel comfortable with doing yourself. For extra money we can deliver the complete ORION System to your doorstep, ready to play. It is up to you how you want to take the ORION challenge. Either way can lead to the same world-class speaker system. 

ORION owners have access to helpful information and updates. The design is stable and has proven itself over a number of years now, but I still keep my eyes, ears and mind open for worthwhile revisions.  

These are the specifications:

  • Open baffle cabinet 
    Outside dimensions: Height 46.25" - Width 13" 
    Depth 2" at top, 12" at base, 16" at 14" up
  • Weight 60 lb (27 kg)
  • 3-way active speaker system
  • Crossovers at 120 Hz and 1440 Hz, both LR4 (24 dB/oct)
  • Crossover/Equalizer using two ORION ASP printed circuit boards
  • Tweeter - Seas T25CF002 - No, not a ribbon - 
    42" up, no 2.8 kHz notch filter as in PHOENIX
    Preferably no grill to cover the tweeter
  • Midrange - Seas W22EX001 - No, not a smaller diameter - 
    Front mounted to baffle, no spine, but see Revision 0.1
    34.5" up, 5 kHz notch filter
  • Woofer - two Peerless 10" XLS, 830452 
    Push-pull mounted in H-frame of 11.5" x 11.5" x 24.5" OD
    Each driver with its own >60 W amplifier
    Response -3 dB at 30 Hz (-6 dB at 20 Hz for Q = 0.5 and -12 dB/oct to 5 Hz)
  • Eight power amplifiers (e.g. ATI model AT6012)
  • Room size: >240 ft2 (>22 m2) area, >8 ft ceiling
  • Speaker placement measured from tweeter: 
    4 ft from wall behind it, >2 ft from side walls,
    speaker separation >8 ft 
  • Listening distance 8 ft to 18 ft
  • Room acoustics: Fairly live with RT60 of 400 ms to 700 ms

The crossover/equalizer is a variation of the PHOENIX design, and that project provides all the necessary background information for understanding the new speaker. The ORION is like a sister of the PHOENIX. See FAQ35 for a comparison. 

If this is your first speaker project, then it could be a major challenge and you should consider buying pre-assembled elements. If you are an experienced speaker builder, then you might be tempted to deviate from the plans. Please do not ask me for design alternatives or personalized changes. You might be drawn to such changes because the ORION does not seem to follow conventional wisdom or mental models with which you are familiar from box speaker design. Open baffle loudspeaker design is different due to the rear radiation whose effect must be controlled and not suppressed. Study the PHOENIX project to understand why the ORION is designed the way it is. The Orion is the result of over 30 years of interest in accurate sound reproduction. I have learned much from my previous designs, recently gained new understanding of psychoacoustic factors and used drivers that were not available before. All this made the ORION possible. You will benefit directly from this when you exactly follow the instructions in the ORION Construction Plans+ documentation. Then your success and satisfaction are guaranteed. 

The ORION can even be adapted to extreme requirements of sound output. Plans are available for integrating the THOR subwoofer with the ORION, in order to increase output volume capability for the very lowest frequencies. This does not change the overall frequency response of the ORION. My recommendation, though, is to first build and listen to the ORION before you decide to add subwoofers. 

THOR subwoofers may be needed for Home Theater applications, either integrated with the left and right channel ORION when no separate subwoofer is provided, or they could be used as subwoofers themselves. Unlike with music, where the bass is always in some sensible proportion to the rest of the spectrum, the low frequency effects channel (LFE,  x.1) will require completely disproportionate amounts of output capability when it is mixed into left and right front channel loudspeakers. But, if a separate subwoofer is connected to the LFE channel, then it is unlikely that the ORION will need further augmentation. 

Have fun, when building an ORION. 
You will be richly rewarded !

Here is a list of people who have built the ORION and who would be willing to let you listen to it.
I invite other builders to add their name to the list, since I get many requests from other places in the US and from around the world. 

In AZ, Tucson, contact John Null for ORION++ or PLUTO+
In CA, Alameda, contact Russ Button
In CA, Healdsburg, contact Don Naples of Wood Artistry, 707-473-0593
In CA, "Central Coast", contact Eric Weitzman
In CA, Sacramento, contact Dan Schneider
In CA, Sacramento, contact George Cherhit 
In CA, Sacramento, contact Johannes Stein
In CA, Sea Ranch at Honeymoon Cottage
In CA, Rancho Cucamonga, contact John Revilla 
In CO, Golden, contact Richard Peck, 303-216-2159
In CO, Indian Hills, contact Michael Patterson 
In IL, Chicago area, contact John Stone
In Maine, Lewiston, contact Steve Telow, 207-242-3379
in MD, Arnold (near Annapolis) contact Rodger Palmer, 410-974-1444
In MD, Baltimore, contact John R Cotterell
In MI, Detroit suburbs, contact Bruce Coppola, website
In VA, Washington, DC area, call Don Barringer, 703-528-2227, 
In WA, Anacortes, contact Aaron Howell, 360-391-3410,  
In WA, Bremerton, contact Dave Reite, 360-377-4791,
In WA, Kirkland, contact Mike Chapin,   
In WI, Chippewa Falls, contact Scott Julian
In Australia, Brisbane, contact Michael Leo , 0411 111 902
In South Australia, Adelaide, contact Keith Taylor,  
In Western Australia contact Steve Rosenberg, website
In Canada, Burlington, Ontario, contact Alan Plaunt
In Canada, Calgary, Alberta, contact Mike Singleton
In Croatia, Zagreb, contact Dragan Fratric,
In Hongkong/South China contact LUNs Mida
In Iceland, Egilsstadir, contact Sigurjon Hauksson
In Italy, Milano, contact Paolo Pacei 
In Japan, Yokohama, contact Kentaro Kumagai / ORION3.3, PLUTO2.1, LXmini 
In The Netherlands, contact Lolke Wijtsma
In Singapore, Singapore, contact Steven Hill
In Slovenia, Ljubljana, contact Zoran Ruzic,
In Sweden, Gothenburg, contact Mattias Andersson

There are ORION owners and DIY builders in many parts of the world:
Argentina, Australia, Austria, Belgium, Brazil, Canada, China, Croatia, Cyprus, Denmark, England, Finland, France, Germany, Hong Kong, Hungary, Iceland, India, Indonesia, Italy, Japan, Kuwait, Latvia, Lithuania, Malaysia, Netherlands, New Zealand, Norway, Philippines, Poland, Portugal, Rumania, Russia,  Singapore, Slovenia, South Africa, Spain, Sweden, Switzerland, Thailand, Turkey, UK, USA (
AK, AL, AR, AZ, CA, CO, CT, FL, GA, HI, ID, IL, IN, KY, MA, MD, ME, MI, MN, MO, NC, NE, NH, NJ, NM, NY, OH, OK, OR, PA, SC, TN, TX, UT, VA, WA, WI).

Note, for privacy reasons I cannot give you the name of someone in your area, who you might want to visit, so you can listen to their ORION system. Use the ORION Owners Forum to make contact with a willing person in your area.


Help with acquiring the ORION

USA - Wood Artistry L.L.C. can build and deliver complete ORION-4 Systems in custom wood finishes, ready to be plugged in. They also offer some sub-assemblies. They also ship to other countries.

U.K. - KJF Audio. delivers ORION kits. Details will show up soon on the KJF website. 
 Contact Stefan Whatcott: admin@kjfaudio.co.uk
They also ship to other countries.

Please note: The ORION materials are copyrighted and for your own personal, non-commercial use. | Terms &Conditions |

| Challenge | Requirements | Supplies | Promotion | Subwoofer | Photos | Reviews | ASP | FAQ | Revision 0.1 | Revision 2ORION-3 | ORION-4 |


CAUTION: The content of these pages may change without notice as I learn new things or find better descriptions. The designs presented here may change as I make new observations or gain more insight. I see myself as a seeker of truth, though I now know that every person is, and ultimately truth is a construct. There is only this. Maybe what has been done here points you to it. Audio has overwhelmingly been a hobby for me, for my own pleasure and love of music. I enjoy to share what I found and possibly to dispel a few misconceptions. My interest is not on the business side, though I like that my activities pay for my hobbies. You may not agree with some or all aspects of my designs, the approach that I take to them, or the theories. I have no problem with that. Just do not ask me "what would happen if ...". Changes that you make to the designs are for your own pleasure and at your own risk. But if you learn something worthwhile, then please let me know. My DIY projects are not for beginners and it may be necessary for you to buy subassemblies or a turnkey system from Wood Artistry. Please do not ask me for individual help with your DIY difficulties. All my designs have a Support Page. It is listed on the cover or inside of your project documentation. There is an ORION/PLUTO/LX521 Users Group with people who can help you. I respond to every email eventually, but you may not get the answer you want. I consider my writings in these web pages as brief and to the point. I labor over every sentence and word and provide little redundancy. Read thoroughly and maybe more than once. I do not write for the rank beginner, but for those who have been around the block. You may need to study up. The links in my text are for that. I have not been standing still since I started this website in 1999 and with the idea of a brain dump of my previous findings so they would not get lost to the audio community. In 2006, after PLUTO, I thought I would go into a support and maintenance mode. No new design. Stuff happened, more enjoyment to share. The recording and rendering process interests me most at this time. Therefore the LX521. Let's see what it will do.  I could stop now and be content with what has been accomplished.    



What you hear is not the air pressure variation in itself 
but what has drawn your attention
in the streams of superimposed air pressure variations 
at your eardrums

An acoustic event has dimensions of Time, Tone, Loudness and Space
Have they been recorded and rendered sensibly?

Last revised: 02/15/2023   -  © 1999-2019 LINKWITZ LAB, All Rights Reserved