Curved Electrostatic Speaker V2 Build

[DriedChalk]

Hello!
After a break I'm back and ready to spend some more money .

My first attempt at a curved electrostat pair was a mostly successful, but they definitely could have been made/designed better. (Thread: http://www.diyaudio.com/forums/planars-and-exotics/291385-curved-electrostatic-speaker-build.html)

I'll be building a new pair of speakers with a few key changes:
-Thinner mylar (6 micron from 12 micron)
-Taller panels (12"x36" from 12"x24")
-More open area on steel panels (64% from 40%, see attached pic)
-Built in woofers and crossovers (NOT just a subwoofer taken from a sound-bar)
-Clear spars (purely cosmetic, but a big improvement Amazon.com: KOOL TAK Clear Foam Roll Tape, 3/16-Inch by 1/16-Inch by 1.6-Yard: Arts, Crafts & Sewing)
-Powder coated panels (spray paint was a real hassle and failed in some places)

More pictures and updates to come!

-Ben

 

[tyu]

"More open area on steel panels (64% from 40%, see attached pic"
Hi....
Martin logan wonted more open mylar in there panels also...but going with biger holds, lowerd output!
They had to go with smaller holes...this gave higher output an more open Mylar..all there new panels have more smaller holes...This setup gave them same output out of a 12"x 46..panels....There were getting out of the biger holds in the 16"x 46 ...they done lot of panel work
just saying....keep up the good work

 

[DriedChalk]

Thanks for that info tyu.
Does anyone know exactly how much my output could potentially decrease? My current panels get plenty loud and since these will be even bigger I doubt that they will be quiet, but just in case.

-Ben

 

[CharlieM]

Thanks for that info tyu.
Does anyone know exactly how much my output could potentially decrease? My current panels get plenty loud and since these will be even bigger I doubt that they will be quiet, but just in case.

-Ben

I've built perf panels with open areas from 40% to 63% and I find the lower percentage open area ones just sound better. The higher open area ones were a bit harsh and also I think the lower open area stators help dampen the diaphragm's drum head resonance. Many builders add some acoustic resistance in the form of scrim cloth behind the rear stator for dampening-- perhaps it's better to go lower open area on the stators instead and use the extra metal to drive the diaphragm. Just my thoughts....

 

[tyu]

I've built perf panels with open areas from 40% to 63% and I find the lower percentage open area ones just sound better. The higher open area ones were a bit harsh and also I think the lower open area stators help dampen the diaphragm's drum head resonance. Many builders add some acoustic resistance in the form of scrim cloth behind the rear stator for dampening-- perhaps it's better to go lower open area on the stators instead and use the extra metal to drive the diaphragm. Just my thoughts....

This is What ML found..they got to use only one stip of the clear rubber for stator on front an back....an small holes help dampen panels...an the smaller holes gave more output from same input...win-win.

I have nothing to do with ML...
I well an have payed for there speaker with dead panels.....an re-work them back to life..

 

[DriedChalk]

I'll definitely go for the 40% open area then. I've got to wondering though, has anyone ever experimented with vertical or horizontal slats instead of holes in the steel stators?

 

[tyu]

Heres the thing.....I have read the Acoustat panels are only 25% open..
40% seems like a great thing....I read also the the older biger holes ML were 50% open....

I have pr of Re-worket ML CLS....22"wide..48" tall....that would be the 50% open, curved panels...I run full rang but theres nothing there below 50-60 hz...be for over lode.... I get great output out of these panels,with just a transfourmer an a one ohm res.....get as good if not better than new CLS panels... with the ML crossover, tone shaping setup I have been told by other owners of the Stock CLS llz an CLXs
An if you pic the ML CLs up off the floor 6-8"...OMG...35 watt tube amp well run you out of a 18'X40" room...make big diff in output...Wow..shocking..well to me....I am posting this info just to help you..see were you may go....good luck ..have fun
Some pix...tuff to get good pix close up

 

[CharlieM]

Heres the thing.....I have read the Acoustat panels are only 25% open..
40% seems like a great thing....I read also the the older biger holes ML were 50% open....

I recall reading somewhere that Panasonic Corporation did some research into ESLs which determined the optimal (max output) open area is 42%.

 

[tyu]

My problem with the newer ML small hole panels sound...I don't like there sound,of the way there new, well was new... type air frame works... the image is to large for me....an it makes it hard for me to get past that... to focus on the output...or sound quality....

"MartinLogan's MicroPerf design optimizes this tradeoff by reducing the size of the individual holes and using many more of them than in a traditional electrostatic panel. MicroPerf almost doubles effective diaphragm radiating area without compromising structural integrity. The resulting increase in output capability and efficiency allows a panel to be made much smaller without sacrificing performance - or to enjoy a substantial leap in bandwidth and dynamics without growing larger."

All this is why for years now...I have been asking...why not do what Quad dose...From the 57 on...put a so called mylar dust cover on the out side of the panel....so the ear hear the flat full sheat of mylar playing sound...not the holds in the panels with the sound....this would fits the ear so much better....
I think it what give Quad there clame to fame...an other things...

But it ezey for me to say these things...I don't diy ESL panels...I only re-work them...

 

[AVWERK]

The only way the Quad dust cover could contribute anything to the sound is if it were stretched tight enough to act as a passive radiator for the low end, but in this case it is just tight enough to remove wrinkles and do its job.

Regards
David

 

[tyu]

Ok...So how is it..acoustically transparent .being lose..an adds nothing to the sound?
Magic....

 

[AVWERK]

Because it’s extremely thin and serves its purpose in dust and humidity conditions allowing the panels to operate at their best potential in owners varying conditions around the world.

The Quads unique sound is not influenced by the “dust covers” enough to worry about.
The grill cloth affects these more than anything else and easily solved . Start there.
I have found the ML,s to initially sound better than Quads, however long term listening (where it counts) the Quads superior in balance and low level detail that ML,s never satisfy. Great looking and decent sounding midfi speakers only, sorry...,

Pics include something you can try yourself . If your rebuilding, then you know which thin Mylar will suffice.
(my SL3 with Quad 988 original dust cover material placed directly over the panel) 988 being rebuilt currently.
Get out your laser pointer and place it 1/3rd in on each panel blah/blah/blah
Give it a Listen and tell me what coloration you notice 👌🏼

 

[tyu]

As for the words Mid-fi....it all mid-fi...there is No high fi...less your having live Performances in your home....

I would never say ML were more than just ....good fun...my CLS were $150ea..so I brag how well they work an sound...hehe
4 pr... SL3 never like sound..of the Hard Plastic Strip under the rubber bars on the back stator ....it come unglued in time...adds it own sound...
The Ascent panel did away with it just used rubbers..... an bass setup..much better panel match...open at bottem an top......but thay were $20ea...yes ML are good fun..for these prices...
Acoustat are also great fun....Quads..only the 57...ever got me there.but Quads... always need work....
I cant live with one pr of any speakers..amps...tubes...preamps...dacs...
life way to short...for me anyway......but I have seen other Quad guy say how much better that all Quads....sound with the Dust covers off....just saying

 

[DriedChalk]

After doing some more thinking and reading I've decided that since I've already made a curved pair and they worked fine that I'll be making some insulated wire stators as per Charlie's blog. I'm gathering parts on line and doing more research, but before I go and do anything does this seem like a better idea? (I'm not exactly sure about what to do about this thread title if I do change this project's direction though )

-Ben

 

[MJ Dijkstra]

As for the words Mid-fi....it all mid-fi...there is No high fi...less your having live Performances in your home....

I would never say ML were more than just ....good fun...my CLS were $150ea..so I brag how well they work an sound...hehe
4 pr... SL3 never like sound..of the Hard Plastic Strip under the rubber bars on the back stator ....it come unglued in time...adds it own sound...
The Ascent panel did away with it just used rubbers..... an bass setup..much better panel match...open at bottem an top......but thay were $20ea...yes ML are good fun..for these prices...
Acoustat are also great fun....Quads..only the 57...ever got me there.but Quads... always need work....
I cant live with one pr of any speakers..amps...tubes...preamps...dacs...
life way to short...for me anyway......but I have seen other Quad guy say how much better that all Quads....sound with the Dust covers off....just saying

I got a modified ML odyssey and they have great low level detail.
Quad sounds good as well but I like power......
And full range needs a lot of space behind the speaker, without that it sounds anemic....

 

[tyu]

I got a modified ML odyssey and they have great low level detail.
Quad sounds good as well but I like power......
And full range needs a lot of space behind the speaker, without that it sounds anemic....

Your are right about the power.....we like it...ML deliver...as much if not more than most esls...

Full range is tuff....I have a 18'x 40'x 14' room all open...so the Acoustat 2+2 play loud with new bias.....5k strong

But the ML...Ascent kick ***....hehe my CLS rock if you get them up off the floor.....I use two Gallo bass ball...with them some times..the bass balls have 10" driver...I have found the ball shape vary hard to out prefourm..with piston type drivers...lot fun
some pic I pulled off the web....

 

[tyu]

After doing some more thinking and reading I've decided that since I've already made a curved pair and they worked fine that I'll be making some insulated wire stators as per Charlie's blog. I'm gathering parts on line and doing more research, but before I go and do anything does this seem like a better idea? (I'm not exactly sure about what to do about this thread title if I do change this project's direction though )

-Ben

"insulated wire stators as per Charlie's blog"....well if you think the flat panels sound is for you...its been some time now ...an if the jazzman still likes the wire better than the medal...he done a lot work...great work I think..
For my ears.....I find adding the res to setup the diff segment on the panel to get "curve" sound output, adds color to the sound...not all bad...but added...
After years of living with none segmented panels...it just diff..for me
But I don't Diy ESL panels...So if the jazzman thinks this way work best..i go with his work....just saying

 

[DriedChalk]

I'm thinking of using this wire 20 Gauge AWG Solid Copper Core Electric Dog Fence Boundary Wire (500 Feet) and buying 4 rolls of it (1 roll per stator). Not sure about whether the insulation would be sufficient though. I've requested a quote from Interstate Wire but they don't seem to have gotten back to me yet.

I'm might getting ahead of myself, but I was looking at buying two of these woofers to compliment the panels: Dayton Audio RS225-8 8" Reference Woofer
Anyone had any experience with these? Their range is 28 to 2,400 Hz, which sounds great to me, but I could be overlooking some other important aspect(s).

-Ben

 

[CharlieM]

"insulated wire stators as per Charlie's blog"....well if you think the flat panels sound is for you...its been some time now ...an if the jazzman still likes the wire better than the medal...he done a lot work...great work I think..
For my ears.....I find adding the res to setup the diff segment on the panel to get "curve" sound output, adds color to the sound...not all bad...but added...
After years of living with none segmented panels...it just diff..for me
But I don't Diy ESL panels...So if the jazzman thinks this way work best..i go with his work....just saying

The wire panels are wonderful and they're far less prone to arcing than perf metal panels. Personally, I would never go back to perf metal panels.

However, wire panels aren't as easy to build as perf metal panels; especially if you opt to stretch the wires. Stretching the wires isn't a necessity (the panel would work fine without stretching the wires) but it's the only way to get them perfectly straight. For my panel design, the wire stretching jig was actually harder to design and than the panel itself.

I would be happy to send you CAD drawings of my stetching jig and panel in DXF format... just PM me if you want them.

 

[AVWERK]

If you get a chance to listen to the Sanders flat panel system anywhere near you , spend an hour of critical listening and you should come away with the best top to bottom performance of any ESl out there.
Easily trounces curved panel designs
Unpolluted first arrival times are more important than wide dispersion design that de focus image size creation.
Easy to hear tight image placement in 3D space with flat panels vs.CP,s

I,m sure Jazzman,s design is close in sound quality being similiar in construction.

Regards
David