I am planning on building my first ESL's. I have eventually sourced perforated mild steel sheets and 12 micron Mylar (the thinnest currently being imported into South Africa where I live). I think I will use 3m double-sided tape for spacers and liquid soap (at least initially) for coating the diaphragm. Ideally I would like to have an ESL panel/panels covering mid/high and a dipole woofer for the base (crossed as low as feasible given the other constraints).
I only know what I have read on the net. I am sure that the books on the subject (e.g. by Roger Sanders) would be very useful. But if I do order one, it would be weeks before it arrives.
Deciding what design to go with is not an easy matter. I would like a sufficiently large sweet spot for at leat two listeners at a distance of about 4m. For this reason, it seems to me that I should be making the panels tall and narrow, not wider than a foot (maybe as narrow as 3 inches) and about five feet high. Is is better to make one panel or stack two smaller ones?
As regards the stators, what hole size is optimum? I can choose almost anything. I was thinking around 3mm, but this is completely arbitrary. Also what thickness is best? 1mm? 1.6mm?
Almost all of the ESLs I have looked at have no added baffle width. Would this not be useful to cancel dipole cancellation at low frequencies, particularly for narrow panels? I haven't done the math, but maybe 6 to 12 inches added on either side. Does this give unwanted baffle step or diffraction effects? This also raises the question of how thick the baffle can/should be.
My biggest obstacle at this stage is the audio transformers. I have not managed to source any locally and I think it would probably be significantly cheaper to get them custom wound than importing them. The local import duties and shipment costs are pricey. Are technical details available anywhere or can somebody help me on this? I would like to stick to one audio transformer per side.
Any advice the list could offer would be much appreciated. I wish I had endless supplies of money and time to spend on research and experimentation...
As an aside, has anybody ever tried using a "digital" amplifier with an internal step-up transformer? It seems to me that such a beast could be directly coupled. The negative feedback would come from after the transformer (via a resistor divider?). Wouldn't this give much better control of the speaker? Presumably a lot of the LC effects could be greatly reduced. Switching noise at these voltages may be an issue though.
Bret
I only know what I have read on the net. I am sure that the books on the subject (e.g. by Roger Sanders) would be very useful. But if I do order one, it would be weeks before it arrives.
Deciding what design to go with is not an easy matter. I would like a sufficiently large sweet spot for at leat two listeners at a distance of about 4m. For this reason, it seems to me that I should be making the panels tall and narrow, not wider than a foot (maybe as narrow as 3 inches) and about five feet high. Is is better to make one panel or stack two smaller ones?
As regards the stators, what hole size is optimum? I can choose almost anything. I was thinking around 3mm, but this is completely arbitrary. Also what thickness is best? 1mm? 1.6mm?
Almost all of the ESLs I have looked at have no added baffle width. Would this not be useful to cancel dipole cancellation at low frequencies, particularly for narrow panels? I haven't done the math, but maybe 6 to 12 inches added on either side. Does this give unwanted baffle step or diffraction effects? This also raises the question of how thick the baffle can/should be.
My biggest obstacle at this stage is the audio transformers. I have not managed to source any locally and I think it would probably be significantly cheaper to get them custom wound than importing them. The local import duties and shipment costs are pricey. Are technical details available anywhere or can somebody help me on this? I would like to stick to one audio transformer per side.
Any advice the list could offer would be much appreciated. I wish I had endless supplies of money and time to spend on research and experimentation...
As an aside, has anybody ever tried using a "digital" amplifier with an internal step-up transformer? It seems to me that such a beast could be directly coupled. The negative feedback would come from after the transformer (via a resistor divider?). Wouldn't this give much better control of the speaker? Presumably a lot of the LC effects could be greatly reduced. Switching noise at these voltages may be an issue though.
Bret