Other ESL build with simple materials available from local grocery stores

[Audio_idiot]

Hi,
This is my virgin thread, I hope I didn't step on other threads on this subject.

I am presently collecting materials for my ESL. I wish to experiment with a small prototype before proceeding into fullrange and high SPL.

I had many restraint in allocating commonly suggested materials for ESL, especially bulky materials which will cost both me arms and legs to ship.

This is how far I had progressed,
The film:- there are no other alternative other then mail order some 6um mylar film,
Insulator:- Plexi glass seems to be the default material for insulator in my location as many thickness can be obtained easily,
##PS, small items shipping cost is ok.

Transformers:- The bias supply can be made easily using common EI step down transformer, the matching OPT needs more thought but can be arrange.

Stator:- Perforated plates are not off-the-shelf item in our local hardware store. Wire stators seems extreamly labour intensive and quality solid core copper wires are rare commodity.

I happened to come across some fine mesh metal mosquito nets and other stainless steel wire mesh for filter.

Question:
I wonder if we can fine mesh metal wire nets as stator conductor by glueing them onto the lighting grates, egg crates or other form of support for mechanical strength?


Cheers

[SY]

I wonder if we can fine mesh metal wire nets as stator conductor by glueing them onto the lighting grates, egg crates or other form of support for mechanical strength?

That can work well- but don't use a very fine mesh, since the percent open area can be low. Normal window screen size would be a good choice.

[bigwill]

I'm also trying to build a test ESL panel out of easily avaliable stuff. Will cling-film or 'saran-wrap' work for the diaphragm?

[SY]

Generally, they're much too thick. You want something about 6-10u. (1/4-1/2 mil in British units)

[medum]

Have a look at this nice australian site:

www.eraudio.com.au

You can buy all kind of parts for your ESL speaker!
ROB MACKINLAY can give advice, too!

Jørn S.

[BillH]

Hi, Audio_idiot.

The wire screen is an interesting product for stators and I haven't seen it used before. You will not have to deal with the problem of sharp edges like perforated material, but I wonder if all the wire ends on the screen will give you a leakage problem.

As you're finding out, getting materials for an ESL is one of the biggest challenges a DIYer faces. I had to order parts from three different places just to build new HV bias supplies.

Bigwill writes: Will cling-film or 'saran-wrap' work for the diaphragm?

In addition to what SY wrote, the cling film seems too 'soft', especially if you're going to use graphite on it. I've got a package of window insulating film that I bought for the double sided tape inside. The film measures 0.005" thick, about 12 micron and is heat shrinkable. It's a bit thick, but if it's available in your area, it may be worth looking into.

Audio_idiot, you'll probably find that your ESL design will evolve as you build according to the materials available. Please let us know how it works out.

[SY]

Bill, the Saran films from grocery stores these days don't even have Saran in them!

FWIW, I use a Saran film (real Saran, PVDC) which works very well, but film that thin is not trivial to obtain.

[bigwill]

Hmmm, I just tried to heat-shrink some cling film and it worked nicely, and it seemed to be pretty strong and robust. You could poke it about a lot and simply apply heat again to get rid of the crinkles. You had to stretch it a lot to make it unable to go back to its original shape leaving permanent creases. I think it would be strong enough to apply graphite to, and any "dents" you put in it whilest doing so can just be heated again. The stuff felt light enough to produce high frequencies, but that's an entirely intuitive feeling not an actual fact..

[Bazukaz]

Hi,
If you want to experiment , a thin baking film may be easy to get , and usually comes in around 12 um thick. A black shoe wax may work for coating .Shoe wax is soluble in water , so it is easy to apply a thin layer of it.
Wire mesh is possible to use for stators , however , it might be hard to insulate it well , like perforated steel. You will have to glue it on support structure , which will not be that easy.
I'd suggest the wire method. It is not the cheapest , and consumes lots of time , but you can build a quality panel. PVC insulated or magnet wire is not difficult to get.To stretch the wires succesfully , you would need a jig. It can be built from threaded steel rods on a wooden frame.The louvers are placed between the rods.The wire is then wound on both stators at once. Then , the wire is additionally stretched. The next (and probably the most time consuming) step is glueing the wires.
Trying to build ESL in a fast way is very likely to result in failure.

Regards,
Lukas.

[bigwill]

Anyone know where you can get mylar in the UK? Or even cheap perforated metal for that matter?