Description of the ESL 175
|Type:||Full range Wire Stator ESL|
|Initial designer:||E. Fikier|
|ESL size:||1600 x 260 x 80 mm|
|HV Power supply:||7500 V|
|Amplifier power:||min. 40 W|
|Sensitivity:||82 (88) dB (1/W/1 m) with an audio transformer 1:50 (1:150)|
|Freq. response:||60 Hz...20 kHz (audio transformer 1:50); 40 Hz...20 kHz (audio transformer 1:150)|
For an exact description of the ESL 175 I have to refer to the book of E. Fikier.
My experiences with this design are not very positive. The diaphragm that I used at first (metalized Mylar) burned away completely and as a result the sensitivity reduced dramatically. A second attempt with foil also used in the Finals got much better results but frequencies below 120 hertz are barely noticeable. Over the period of a year sensitivity reduced and the deformation at normal levels is enormous. According to E. Fikier this type of electrostat -with the used audio transformer and high power supply- should work well down to 60 hertz. There are also some mistakes in E. Fikiers book.
I am planning to build a smaller ESL with a crossover point at about 300 hertz with a active woofer with power amplifier.