Personal Planars.

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Member
Joined 2004
Paid Member
Quick answer? From what I can tell, you are exciting a chamber bounded by two diaphragms by feeding it the dynamic speaker's back wave? That would fit "Bi-polar panel driven by pneumatic compression...."
So it's related to bass reflex loading? As it doesn't take much to "destroy" computer speakers, I guess I'll take his word for it, but I think you're listening to a little speaker pumping a plastic bag. Looks cool, though. There: I said something nice about it!
 
For full range operation they would need a "motor" that has full range capability. Response? Who knows.... a good bass motor won't produce good HF. A good HF motor will lack bass.

Dipole? Not quite. Each diaphragm radiates in both directions. At the frequencies where the spacing between the diaphragms is and odd multiple of 1/2 wavelength, the front radiation of the rear diaphragm and the rear radiation of the front diaphragm will cancel so what's left is the front signal from the front diaphragm and the rear signal from the rear diaphragm and those are in phase at the diaphragms, so response will not be dipolar.

Is the motor vented to the outside world, or just to the space between the diaphragms? If it is vented the response will be a real complex function of the the response from the port and the response from the diaphragms. A real nightmare to predict.

Probably best suited for computer speakers where wide response and sound quality are usually secondary considerations.

I_F
 
tade said:
it certainly does look cool. i was excited about it being a new sound producing design. maybe it isnt new and just terrible. i am tempted to build one to see, ill tll you all how it goes.


Just stumbled upon this older thread - and I too was interested in building these. I was wondering if you ever did build them, tade? If so what was the outcome? I'd be interested in what happened for your project.
 
This reminds me of a speaker that Sumo (high end electroincs) was selling at one time, even though yours is quite different in operation.

It looked like a flat planar with a conventional foice coil attached to it's center.

They were promoting it with the "pebble thrown in the water ripple effect" or something like that. Someone reviewed at one time Stereophile or Absolute Sound I think.

Not much came of it, but it got a decent review.

sorry if this is WOT, but memory's have to start somewhere!

David
 
Sumo Aria by Highwood Audio

Avwerk: the speaker you are referring to was the Sumo Aria and was designed and manufactured by Highwood Audio of Calgary Alberta Canada. The review you spoke of was first published in Audio June 1992. There were also one or more reviews in Stereophile on Hybrid versions later. Sumo had financial troubles and the team of Sumo (distribution) and Highwood (manufacturer) split. Highwood Audio then merged with Museatex Audio (Ed Meitner) and released a new version under the Museatex name. That went for a couple of years until Museatex management killed the speaker after ******* around with it. The speaker was designed by myself Paul Burton and John Wright. John has since taken over service and modification of Museatex and Meitner equipment as well as designing new equipment, Paul is now back working in Britain and I am designing ausio cables and interconnects. Was a good design as a point source. Our first version (and best) was a line source which we never got to market. Maybe some day who knows. Ed carried on to start EMM Labs which you probably know about and is still here in Calgary. Hope that this helps.
The two designs are not at all alike but it is interesting to read that somebody remembered the old highwood speaker. Best regards Moray James.
 
Highwood Audio

Capaciti: Manger was not in a position to challange Highwood Audio over the design. Manger did make inquiries to HIghwood but was advised that they were not in a position to take any action nor did they ever do so. Highwood Audio investors actually assumed Meitner though Meitner management did run the two merged companies after Museatex/Meitner moved to Calgary from Montreal. Meitner (the company) did not really want to persue the loudspeaker and finally gave up on the idea of marketing speakers. Best regards Moray James.
 
lots of reasons

Well the motor structure alone cost us $375.00 CND each to build in house at the time (1990). Museatex had it own agenda and Highwood Audio was not included. There were lots of things going on at the time and it just did not work out that's all. I think that it was a good design that worked well and sounded good. The very best versions of that speaker never made it to market. Maybe in another time. Regards Moray James.
 
Pebble in the pond

Moray James,

Can you tell us more about how the line source might work with this concept? I have read the original patent and it was quite intriguing.

Why did the motors cost $375? It seemed like a conventional voice coil??

Please tell us more if that is possible.
 
Well long story

The motor used H7 ceramic magnets the pole was vented and the magnet cavity was vented. The pole had a full copper sleeve and there was also a copper shorting ring at the base of the pole and a copper ring inside of the top plate. Theses were necessary to achieve extnded bandwidth. We used fero fluid in the gap to act as a liquid bearing to help keep the voice coil stable. The coil was a four ohm single layer coil again to minimize inductive roll off. There was just over one tesla in the gap. Top plate was 3/8 inch thick. Voice coil was 1.25 inch kapton with a coil of around 32 or 34 guage. The voice coil gap was about the same as a typical dome tweeter. You can imagine this as a bigish tweeter with the worlds biggest suspension. Diaphragm was 150 guage mylar HS. We looked into using neo magnets but they were still on some military list back then and supply was not a dependable thing then.
The line source came first but we were worried that the magnet structure would cost too much. That was before we added alll the tricks to the point source motor. We built both single ended as well as push pull versions of the line source. We used H5 ceramic magnets with iron pole pieces. Efficiency was not too bad at an honest 87 db (not just at 1KHz). I think we used 32 - 34 guage magnet wire (copper clad aluminum). There were eight or ten turns connected via a harnes so all the turns were in the same direction. The stage and image qualities of this speaker were world class I don't think that I have yet to hear the equal. That's about all I can recall at the moment. The real trick is to deal with terminating the traveling wave as it reaches the frame where you don't want it to reflect back into the diaphragm. Regards Moray James.
 
Yes I know this is a very old thread...but...

Avwerk: the speaker you are referring to was the Sumo Aria and was designed and manufactured by Highwood Audio of Calgary Alberta Canada. The review you spoke of was first published in Audio June 1992. There were also one or more reviews in Stereophile on Hybrid versions later. Sumo had financial troubles and the team of Sumo (distribution) and Highwood (manufacturer) split. Highwood Audio then merged with Museatex Audio (Ed Meitner) and released a new version under the Museatex name. That went for a couple of years until Museatex management killed the speaker after ******* around with it. The speaker was designed by myself Paul Burton and John Wright. John has since taken over service and modification of Museatex and Meitner equipment as well as designing new equipment, Paul is now back working in Britain and I am designing ausio cables and interconnects. Was a good design as a point source. Our first version (and best) was a line source which we never got to market. Maybe some day who knows. Ed carried on to start EMM Labs which you probably know about and is still here in Calgary. Hope that this helps.
The two designs are not at all alike but it is interesting to read that somebody remembered the old highwood speaker. Best regards Moray James.
 
Sorry key miss hit and cant see any edit button....thread brought back becaue I was blessed to have come upon a pair of these in like new shape and they sound unlike anything else I have ever laid my ears upon......heavenly to say the least
 

Attachments

  • 346104156_tp.jpg
    346104156_tp.jpg
    20.8 KB · Views: 226
  • 346104200_tp.jpg
    346104200_tp.jpg
    13.1 KB · Views: 222
  • 346104274_tp.jpg
    346104274_tp.jpg
    21.2 KB · Views: 219
The line source came first but we were worried that the magnet structure would cost too much. That was before we added alll the tricks to the point source motor. We built both single ended as well as push pull versions of the line source. We used H5 ceramic magnets with iron pole pieces. Efficiency was not too bad at an honest 87 db (not just at 1KHz). I think we used 32 - 34 guage magnet wire (copper clad aluminum). There were eight or ten turns connected via a harnes so all the turns were in the same direction. The stage and image qualities of this speaker were world class I don't think that I have yet to hear the equal. That's about all I can recall at the moment. The real trick is to deal with terminating the traveling wave as it reaches the frame where you don't want it to reflect back into the diaphragm. Regards Moray James.

Can you explain this? Is something like eminent technology push pull planars?
Or your line source prototype was like a DML?
 
this was a vertical line source, all the turns on the diaphragm were in parallel and a harness took each turn off the diaphragm at the top and returned it to the next turn at the bottom so it was out of the magnetic circuit along the outside edge of the speaker frame. We experimented with a number of motor magnet structures as I said both single ended push push and push pull. This was not like an ET as we were driving the diaphragm as a line source not over its whole surface area. There was no attempt to make pistonic diaphragm motion strictly traveling waves. Please note that we are not talking here about the design that was taken to market as is shown in the pictures above. The line source was never marketed. Hope this helps.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.