Hallo ihr vertrockneten Sägemehlmampfer 
Um AH´s Kalottenpanik weiter zu forcieren *g* hier much more insight in the BMR Funzprinziep :
http://www.aes.org/sections/uk/meetings/a0701r.html
Und es gibt da noch ne 12MB MP3 - Audiolecktüre zum in die Ohren schaufeln :
http://www.aes.org/sections/uk/meetings/a0701.html
http://www.aes.org/sections/uk/meeti...cture_0701.mp3
Paul Burton im DIYAUDIO Forum hat diese Infos&Links geliefert , ihm gebührt Ruhm und Dank dafür .
häppy schraub & löt - bye!
KK
PS: trotzdem viel Spasz noch mit ViSaToN Produkten
-------------------
http://www.diyaudio.com/forums/showt...0&pagenumber=3
For those of you following this thread who may want to take a look at the patent, you can view it online at esp@cenet:
The best document is the European application, EP0296139, as it has all the drawings (called "Mosaics" by esp@cenet). The direct link below might work, otherwise you will have to do a number search:
http://v3.espacenet.com/textdoc?DB=...X=EP0296139&F=0
There may have been other IP generated after I left Highwood (I don't know), but this is the original patent.
A strange thing is that this patent actually contains two inventions: A line source and a point source. This is not allowed under international patent law (as I have since learned), but the patent examiners never noticed. Had they done so, they would have required the filing of "divisionals" and there would have been two patents. Had it ever been wheeled into court it would probably have been judged prima facie invalid on this basis.
The line source was never commercialised because it was too inefficient and didn't have enough bandwidth. In other words, it didn't really work... The existence of a patent is no guarrantee that the invention is workable, or useful.
The Sumo Arias were reviewed in Absolute Sounds (Vol. 62, I think) and there was a good explanatory article in Hi Fi News, although unfortunately I have lost my copy, so I can't give the issue number. Anybody got a back collection who could look it up, sometime in the late 80s?
There is also a description in Martin Colloms' book "High Performance Loudspeakers", including the new edition, right next to the section on Manger.
Moray is quite right, the speakers did work well (eventually, after the liberal application of $$$), and produced a flat response from 40Hz to 20kHz, with constant wide directivity. They did this without any form of equalisation or crossover.
He is also correct that they were very hard to get right, and proved James B. Lancing's (JBL) adage that "Loudspeakers are 90% glue" to a greater extent than anything else I've worked on before or since. Not for the fainthearted or shallow of pocket...
So, I'd second Moray: Electrostats have to be a much easier route to high performance home made di-poles.
Bear: As Moray says, travelling wave radiators do work. They are a true low mass "coherent" source, behaving as a virtual point source located behind the panel. You might like to contrast them with their conceptual opposite, the quasi-random Distributed Mode Loudspeaker (DML), which is an "incoherent" defuse sound source. (see the technical white paper at NXTsound.com for an introduction).
The point source is an acoustic radiator who's behaviour is easy to analyse and model, but is damn near impossible to build. On the other hand, a DML is nearly impossible to analyze and model (the maths is extremely complex), but once you have managed to do so, it is really easy to build one.
...And now there's the Balanced Mode Radiator (BMR), courtesy of Dr Graham Bank of Celestion SL600 fame. That's what this forum should be concentrating on, never mind the Heils, Mangers and Arias of 20 years ago. Much more interesting.
BMR patent: WO2005101899.
There is a recording of Dr Bank giving an AES lecture on BMR here:
http://www.aes.org/sections/uk/meetings/a0701.html
He makes it sound so obvious... But it isn't. It's very, very clever stuff. It should by rights transform the industry. But I wonder if it will? Ten years ago, we all thought NXT was going to do that, and look what happened.
Regards,
Paul
Um AH´s Kalottenpanik weiter zu forcieren *g* hier much more insight in the BMR Funzprinziep :
http://www.aes.org/sections/uk/meetings/a0701r.html
Und es gibt da noch ne 12MB MP3 - Audiolecktüre zum in die Ohren schaufeln :
http://www.aes.org/sections/uk/meetings/a0701.html
http://www.aes.org/sections/uk/meeti...cture_0701.mp3
Paul Burton im DIYAUDIO Forum hat diese Infos&Links geliefert , ihm gebührt Ruhm und Dank dafür .
häppy schraub & löt - bye!
KK
PS: trotzdem viel Spasz noch mit ViSaToN Produkten
-------------------
http://www.diyaudio.com/forums/showt...0&pagenumber=3
For those of you following this thread who may want to take a look at the patent, you can view it online at esp@cenet:
The best document is the European application, EP0296139, as it has all the drawings (called "Mosaics" by esp@cenet). The direct link below might work, otherwise you will have to do a number search:
http://v3.espacenet.com/textdoc?DB=...X=EP0296139&F=0
There may have been other IP generated after I left Highwood (I don't know), but this is the original patent.
A strange thing is that this patent actually contains two inventions: A line source and a point source. This is not allowed under international patent law (as I have since learned), but the patent examiners never noticed. Had they done so, they would have required the filing of "divisionals" and there would have been two patents. Had it ever been wheeled into court it would probably have been judged prima facie invalid on this basis.
The line source was never commercialised because it was too inefficient and didn't have enough bandwidth. In other words, it didn't really work... The existence of a patent is no guarrantee that the invention is workable, or useful.
The Sumo Arias were reviewed in Absolute Sounds (Vol. 62, I think) and there was a good explanatory article in Hi Fi News, although unfortunately I have lost my copy, so I can't give the issue number. Anybody got a back collection who could look it up, sometime in the late 80s?
There is also a description in Martin Colloms' book "High Performance Loudspeakers", including the new edition, right next to the section on Manger.
Moray is quite right, the speakers did work well (eventually, after the liberal application of $$$), and produced a flat response from 40Hz to 20kHz, with constant wide directivity. They did this without any form of equalisation or crossover.
He is also correct that they were very hard to get right, and proved James B. Lancing's (JBL) adage that "Loudspeakers are 90% glue" to a greater extent than anything else I've worked on before or since. Not for the fainthearted or shallow of pocket...
So, I'd second Moray: Electrostats have to be a much easier route to high performance home made di-poles.
Bear: As Moray says, travelling wave radiators do work. They are a true low mass "coherent" source, behaving as a virtual point source located behind the panel. You might like to contrast them with their conceptual opposite, the quasi-random Distributed Mode Loudspeaker (DML), which is an "incoherent" defuse sound source. (see the technical white paper at NXTsound.com for an introduction).
The point source is an acoustic radiator who's behaviour is easy to analyse and model, but is damn near impossible to build. On the other hand, a DML is nearly impossible to analyze and model (the maths is extremely complex), but once you have managed to do so, it is really easy to build one.
...And now there's the Balanced Mode Radiator (BMR), courtesy of Dr Graham Bank of Celestion SL600 fame. That's what this forum should be concentrating on, never mind the Heils, Mangers and Arias of 20 years ago. Much more interesting.
BMR patent: WO2005101899.
There is a recording of Dr Bank giving an AES lecture on BMR here:
http://www.aes.org/sections/uk/meetings/a0701.html
He makes it sound so obvious... But it isn't. It's very, very clever stuff. It should by rights transform the industry. But I wonder if it will? Ten years ago, we all thought NXT was going to do that, and look what happened.
Regards,
Paul
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