just to shake things up

How about building some ESL panels sideways with 100% solid flat insulated stator plates? They will require that one edge on either side of the diaphragm be left open so the air can escape when compressed by the diaphragm (front side/back side). You could run multiple sets side by side to boost output. You could even use this idea to make an electrostatic compression driver. Any thoughts??? Regards Moray James.
 
I'am no artist

Sy: imagine that the stator plates are powder coated steel (solid flat). Now we have a diaphragm in the middle of 1/16 inch stator spacers(1/8 inch PP). If the unit is 4 inches deep by 36 inches long you will need to leave out two of the long stator spacers. One on the front (long) edge of the panel the other long one on the back (long) edge of the panel. The missing spacers will have to be on opposite sides of the diaphragm. So while the air is being squeezed out the front side of the panel on one side of the diaphragm it is also sucked in at the back side of the panel on the opposite side of the diaphragm. Does that make sence? Efficiency should be a high as it can get given solid stators with insulation. My only concern is air turbulance as the air compressed by the diaphragm is forced to exit/entre the unit via a gap only 1/16 of an inch by 36 inches long. Are ya with me? Regards Moray James.
 
Wish I could draw

Sy: this simply a regular ESL but with solid non acoustically transparent stators. So the sound can only come out if you put a hole somewhere. Turn the speaker sideways (so you are looking at it on edge) leave out just one stator spacer on each side of the panel on opposite sides of the diaphragm. So we are looking at the edge of the panel and one spacer on one side of the diahragm is missing and the opposite spacer on the opposits side at the back of the panel. So the diaphragm moves to the right and pushes air out the front edge of the panel while it sucks air in on the back of the panel on the opposite side of the diaphragm. Does that make any better sence? This is like a bad English comprehension test. Regards Moray James.
 
Any way you build it

Sy: I figure that any way you build a dipole you have out of phase waves from front side to back. So what's the difference? Am I missing something here? Could make a cool compression driver. I agree that turbulance could be a problem that was my first concern. Could build a hot damn line source tweeter though no trouble. Very wide dispersion. For horn loading very easy to set panel FS to match the horn. what do you think? Regards Moray James.
 
Clairifacation

Sy: perhaps I should have said 4 inches deep. The idea is to have just one edge of the panel fireing forward with the opposite (back) edge fireing backward. Does that get us both on the same page? That way if you wanted more output you could laminate a bunch of these side by side by side to yield a combined output in a lateral stack of an inch or two wide. That should have a lot of air moveing. I suppose that you could control the depth to offset turbulance. Just a twist on the conventional format.
Built in a single panel configuration and used as a tweeter you could have a high output tweeter in a line source a 1/16 if an inch wide as long as you like. That should provide excellent dispersion. Enough output to keep up to a horn mid and or bass horn. Regards Moray James.
 
Cal, I'm not a bug about capitalization. A regular ee cummings, that's me.

Moray, physically, the situation is different than with a flat planar dipole. It seems to me that you've got interference between the part of the diaphragm closest to the listener and the part farthest away. And that lag will always be 4" times speed of sound.
 
Well

you could simply put the whole thing int a baffle flush at the front side. would seem that most dynamic drivers are 3-4 inches deep anyway. the baffle could slant/fold back to the back side of the panel like a triangle.
well I like SY it's a good name with a good sound, never met a woman who made that sound that I did not like. Initials are supposed to have periods are they not? God just like ...... never mind. If SY wants me to use his name he will tell me his name. There are ways around the terbulance issue but they mka the structure a little more conplicated. Heils squeeze a lot of air too but not over such a big area. Might just have to build one of these to find out how bad the wind noise would be. Regards MJC
 
Re: Well

moray james said:
you could simply put the whole thing int a baffle flush at the front side. would seem that most dynamic drivers are 3-4 inches deep anyway. the baffle could slant/fold back to the back side of the panel like a triangle.
well I like SY it's a good name with a good sound, never met a woman who made that sound that I did not like. Initials are supposed to have periods are they not? God just like ...... never mind. If SY wants me to use his name he will tell me his name. There are ways around the terbulance issue but they mka the structure a little more conplicated. Heils squeeze a lot of air too but not over such a big area. Might just have to build one of these to find out how bad the wind noise would be. Regards MJC


lol I guess I got ya thinking huh? ;)

I believe the attached pic is your idea no?

the compressed waves should be the same exiting times if the diaphragm is centered... is should work like a dipole horn... shouldn't it?
 

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SY said:
Call me anything you like- you've got lots of good ideas and aren't afraid to throw them around.

I'm thinking that if you made the slot shallower (say an inch), you'd push the interference frequency out of the midrage. Couple that slot to a horn and maybe you've got something.

this design is not to be with a lense... all that I would use would be a small turbulence reducing quarter or half round wood trim...

IMO it SHOULD be somewhat like a horn loaded ribbon... but much more powerful
 
Umm, I posted to another thread where you brought this up...

Interesting idea.

But if the spacing between the stator and diaphragm is 1/4 wave at some freq of interest, problems...

I thought you were aiming for firing out the small end (usually the bottom or top) of the cell! No?

Out the side?

It's got to create compression or else you'll have interference issues in the cell area... if the transition from the slot out the air isn't 1:1 impedance, you'll get a reflection problem (problems). Turbulence isn't the main problem.

Also if you use more than one cell, the "dead" area between cells will be an issue... that distance between.

As far as it being "more powerful" than the same cell firing normally? How could it? Only if it creates compression and that compression is then transformed from a high strength small motion to a low strength large motion (horn, etc...) I would expect.

Sy, I would think that IF the unit was compressing and there were no "1/4 wave" resonant issues that there would not be a "transit time" issue from the front to the back of the cell area since the air volume would act like a single viscous "object" and there would be no travelling wave to propagate?? (think "bubble/balloon??)

_-_-bear :Pawprint:
 
Hi

The basic idea is nice. If you would stack the cells (as you describe them) from floor to celing , you would get a near perfect line-source. As the width of the speaker is very small, the transient responce will not be "smeared" in the horizontal plane.

However...

The cells would have a hard time pressing out air through the sides of the panel, at least at high volume and at low frequency. Using this priciple for mid to high frequencies might possibly work though. If the width of the output slit could be held very narrow (less than 1/2") it would prevent high frequency beaming.

There is another guy how has thougt along these lines before. He put the cells (flat side to the listner) and used an acustic-lens in front of the cells to guide the sound vaves to a more narrow width, creating the same effect. Read more here:

http://www.beveridge-audio.com/White_Paper.htm

/Urban
 
This is not correct, afaik.

The Beveridge uses a standard ESL cell, the same sort of flat perf metal cell that is common. The difference is that Beveridge uses an acoustic lens in front of the cell that produces a broad band 180 degree dispersion.

The amount of compression is minimal, and is mostly due the requirement that the path length along the lens is equal to maintain phase so that the polar response is even at HF.

1/2" width, imho would be too wide for even polar response, you'd get a nasty comb filter effect at some audible frequency.

_-_-bear :Pawprint: