ESL Diaphragm coating

[geraldfryjr]

Originally Posted by DeltaStar

Never read the whole thread, but I was thinking of building a electrostat. Wouldn't roughing a stretched mylar film with a 1000grit 6" body sander make suitable surface for coats to stick to? Al

Roughing the surface is not necessary.
You don't want a rough surface on the diaphragm as this would promote the leaking of the the charge to the air from the microscopic sharp points and edges.

Roger Sanders and I had talked extensively about this and that is how he explained it to me.

Also mylar is a very tough and inert material and the cutting action of the abrasive would weaken it as it is very thin and slightly brittle per say.
It would most likely cause it to break easily when tension is applied to it.

It would be great to see another DIYer do an ESL build as it is really worth the undertaking and the end result is extremely satisfying!!!

There are plenty of us here to help you should you have any doubts or questions as to how to get started.

There are several different ways and methods to build them.
They can be made out of almost any thing and any size you wish.
I like to build little desktop models and I will be building a bigger set sometime soon.
Here is a link to my Latest builds,

ESL Builds and Works in Progress

Good Luck !!!

jer

[tyu]

Nice forum jer....thanks for the post

[geraldfryjr]

Thanks!!!

It is Brand New and is dedicated strictly for ESL's but there are other sections as well.
All are welcome to check it out.

Cheers !!

jer

[CharlieM]

I agree with Jer... roughing the diaphragm is not necessary; especially if using Licron Crystal coating-- it's isn't cheap ($50 a can with shipping) but it's light and durable, works great and it's formulated to stick to plastics. The center spacers on my latest ESL panels are bonded directly to the coating and haven't come unstuck in the 3 years since. Some other coatings may work well too but I have complete confidence in Licron Crystal.

[tyu]

CharlieM..
You are right about your point.. an i have trust in what you say...Your work is some of the best ESL diying i have ever seen....An thank you for giveing us all the info you have.
I just wonted to try to find what would work... an in my setups this is... eze for anyone to get... low cost....an work great...
if i were to ever Diy panels that i could not take apart...an i only got one shot... i would have to go with what i could find like the Licron.. or what other ESL sites sale as coating...but here in fl the air is so wet...90% of the time..if i cant clean the panels ones a year ...i just go bact to the Apogee an Magnepans..

[DeltaStar]

Hi, What is the largest size of panel one could build without encounting a bunch of problems? Thanks Al

[geraldfryjr]

Typically sections not wider than about 8 inches or so as the wider you make them the more directional they become.

Most use many sections of about 3" wide.

I like the 3" wide ones as they don't start becoming directional until at about 4Khz.
I have not tried building anything narrower yet but I have thought about it.

This is why I am trying a electrically segmented stator design now.

I have some 10.5" wide 3' long TIG rod stators that I have made for some bass panels that I have to finish yet.
These will either be run fullrange or mated with a 4" or 5" segmented Midrange/tweeter panel.

Anything wider you may run into a stability issue with not enough tension and/or have to use a thicker mylar of .5 mil or more.
I had a hard time getting enough tension on my 7.75" wide panels using .25 mil mylar, But I did get it to work.

I don't have a mechanical stretcher and I use the heat gun method to tension the diaphragms.

Typically a 12" to 16" wide panel in 3 to 5 sections about 4' high will make you a very nice sounding panel using a woofer of some sort for every thing below about 250hz to 500hz denpending on the D/S (diaphragm to stator) spacing that you choose.

1/16" is good for 500hz or so any lower you need to go more like 3/32 (.093") and a higher bias voltage as well.
But not more than 1/8' or 3mm for a very wide panel.

I will be exploring this in more detail on my new build and will be presenting some solid info on such guide lines.
But those are the ones that you should consider when looking for materials and the method you should choose for construction.

Your D/S to width ratio should be no higher than about 1:100 for good stability.
I like to go a little lower as much as 1:45 or even 1:30 for that extra room for excursion and my smaller panels.
This helps at the lower frequency's to keep the Diaphragm from clipping (slapping) into the stator.

jer

[tyu]

jer
Youll dig this ,... i know your panels are all open...got be the best sound you can get.....
so how do we get a ML or any panel thats output of like 90db at one watt.. to give wider sweet spot ...big 3D stage...an out off about 95db at one watt....
I have working on the ML panels from 95....
ML found tha 9" wide by 40 1/2" tall panel would have some of the best sound if setup right .....
but if thay went with that panel some would never need a biger panel....so the way thay got the panel to put out less was buy adding cross staders....all there panels are setup this way...as are a lot of other panels diyed an so on.....so we know the way the panels are put to gather is the Mylar is glued to the [back] only... so all the cross staders are on the back ....thats were the glue is...an althe way around...like in the pixs....
so how i did to get more output out of the panels...was just take off staders after the metel was formed so there way less cross staders on the front part of the panel....this lets the ear hear much more output of the mylar...an the sound is much sweeter..an matchs the base driver just like it was a ESL also....
Now some well say... an on paper it may... the front staders have more to do with panels sound.. than just the output..... well all i can say... is if you get any panel of ML part...give it shot....

I think people like Jazzman an others has had the sound from day one... has to be even better ...with there panels setup like the Acoustats with NO..cross staders....on the mylar...

In the pix... of the front part of the panel you can see theres one cross stader in the middel...
the spekar i have working now an sound the best yet... have 3ea are the top an 3ea at the bottem only...

This coaeting has give me the best out put yet......have fun... keep diying ESLs

[tyu]

Here are the Aerius i...
I have had these from the 90s...cool thing.... this pic is when the panels put back to gather after this mod.... it looks like all the staders are there..cant tell there out.......by looking


.An i posted about this mod on the back bar of the speakers at the top..
one more way to cut output....
But on the biger Logans like the Ascent i... it get to much...well if there is ...too much...of any thing...... the stage GETS REAL BIG.....but it just 6 small swres...an you take it in an out......
On the Aerius i this remove of the top bar.. works like a charm...an you can add it back if you
like...
these have never souned better....befor these mods there no way i could live with the sound of the Aeraus...Vary Dark sound....like jim powers of ML told me in the 90s when i cap tell him after he sent me free new panels....thay sound no better than the 1 years old one.... look at the panels we did all we could to turn it off.......have fun

[DeltaStar]

Have you ever thought about a tuning system for the diaphrarm as like on apogee's? wonder if be possible? Al