The project

The Year 1992

It al started somewhere in 1992. I was sniffing around in the local library and found a Dutch book about building ESL written by "E. Fikier". I read the book and was very impressed by the idea of building your own speaker (and not an enclosure just like the most DIY speaker projects) that would sound great (according the book) and even look great. So I bought myself a copy of the book, rushed down to the woodshop and started to build the panels exactly as explained in the book. Ordered 6 meters diaphragm and also started building the HV power supply. Even before I was half way the building process I found out that is was not as easy as I thought. The wooden frame design was not very strong and one of the biggest errors I made was!. patience in the building process. So after a uncontrolled start, my ESL project died (just like as many of my other DIY projects).

December 2001

I read the book of "E. Fikier" several times and during a short holiday I decided to build a test panel for two reasons. The first reason was to find out if some idea's I thought off for the building of the MDF panels would work, and the second reason was to find out how the speakers would actually sound. So after 3 days building I hooked up an old Sony amplifier to the electronics (the transformers I used where two small 100 Volt PA audio transformers placed in series). And there it was!!!!.. sound! clear sound, I was really surprised ! During some more testing I blew up the amplifier, I made some calculations of the impedance and I knew it was very low, but I thought the amp could drive it. Repaired the amp en tested further with resistors for security placed in series with the panel.

At this moment I decided to build 2 panels. But thinking of all the other projects I once started and didn't finish, the idea was to first build the panels and afterwards buy the necessary electronics. The basic idea was to build two mid/high ( 200 Hz >) ESL panels and one central bass speaker (< 200 Hz) combined with an active crossover filter and a separate (bass) amplifier.

January 2002

Bought standard sized MDF wood, and started with a plunge router to take out the mid section. This way you will get an less thick panel which also is stronger compared to the building process written by "Fikier". Used round 10 mm aluminum pipe (standard curtains rails) for the stator strips and also used the plunge router to chip out 12/10 mm for fixing the pipes for an bigger gluing surface and easier construction (picture 1, 2 and 3).

Gluing the pipes (which will be done after painting the panels of course) is very easy. Place the glue into the created spaces, place the pipe on top of the glue. Turn around the whole panel and make sure there is an thin layer of paper between your working bench and the gluing area of the pipes, and make sure the panel is flat on your workbench. The stator strips will drop down by there own weight, this way you will end up with perfect aligned stator strips.

At the very early building stage I decided to fix the 2 panels together with screws because of two reasons;

  • Making the panels identical is not easy, but fixed together with screws you can create almost symmetrical panels.
  • I was planning to use double sided tape to fix the spacers and the diaphragm, together with the screws this would be an stronger construction.

Next thing to do is the painting part, this will take a lot of your "building" time.

Placing the wires was the next step. Make sure the panels are fixed flat to your working bench and try to use the same amount of tension when applying the wires. For the gluing of the wires I made an mould. I placed on the stator strip between every wire an little spacer of the desired distance. Took an small piece of wood and fixed double sided tap on it, now place this on top, remove it and now you have an mould. I also placed an little nail in the strip and this should be placed against the side of the panels as an referential point when gluing all the other stator strips.

June/July 2002

Panels are finished and look great, also tested them with the old electronics and they are working! Next step is to find two transformers. So I started looking on the internet (already read the most projects at the TAC site) and wrote an email to Hans. I asked him If he could provide only the 2 transformers used in his NSS package and his advice was to buy the NSS 0.3a kit. Because I also had to build the bass part, HV power supply and the crossover I thought this was an very good idea, so I ordered the NSS 0.3a kit.

August 2002, Sound check

The basic idea was to build one central bass enclosure/crossover/amplifier but the NSS kit provided al the other parts to finish my project. Next step was "Build the standard NSS bass enclosure !". Because I will use the NSS passive crossover filter the amplifier load will be higher, and this way I don't have to worry that my amp will end up dead.

When I hooked up the total speaker and listened to it I thought the output of the ESL panel (in opposite to the bass speaker) was to low. The panels where designed for 200 Hz and up and therefore I used 3 mm spacers. But by using the NSS 0.3a package the panels start at 400 Hz, so I think it would have been better to use 2 mm spacers.

But after listening to several cds I may say that the actually sound great. Clear sound (really clear), beautiful clean voices, and all thinkable instruments are present! And also very important, I have got some great looking design speakers totally build by myself.

November 2002, Tweaking Month

  • For higher high/mid output I doubled the HV power supply by adding 6 diodes and 6 capacitors.
  • The panel listening angel is very small, therefore I did some segmenting by using resistors.
  • For a better adjustment of the mid/high section with the bass part I'm thinking of bi-amping (still in progress)

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Conclusion

I had some great time building the speakers. At first I didn't believe you could build your own speaker and end up with a high end design product. One thing must be said, when you are going to build yourself some ESL panels is, TAKE YOURE TIME, try to think ahead during the building process and be patience. When I started the first time in 1992 I couldn't wait and didn't take the time for building.
The used design order is a bit strange, but because I found the NSS 0.3a kit, my design changed positive. For all those people who are still having doubts of building your own ESL panels ; don't wait any longer and get start building!

For the Dutch readers the book of "Fikier" is an great book to read I don't know if you still can buy it, but it can be found on the internet (illegally). If somebody is interested in any detailed parts of the building process, send an email to esl@assouw.myweb.nl

To Hans, much thanks for creating the fabulous TAC site which's provides so much info about ESL and all related things, and for your perfect and fast service.

Specifications

Based on an design by "E. Fikier" / NSS 0.3a

ESL wired stator 0,75mm2 black copper wire
Frame size 20 x 120 x 43 mm
Effective diaphragm size 11 x 100 mm
Diaphragm Mylar metalized, thick 6 mu
Amplifier power min 40 W
Transformer NSS 0.3a step audio transformer 1:128
HV supply NSS 0.3a ±5000 Volt (doubled original HV supply)
Bass enclosure NSS 0.3a standard bass enclosure
Crossover Filter NSS 0.3a passive filter 400 Hz

Pictures

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