Electrostatic speakers are special kinds of speakers. They use a diaphragm, which is thin, flat and it consists a plastic sheet. This sheet is saturated in graphite like conductive material. This material exists in between two grids, which are electrically conductive. In between the diaphragm and grids, there is a small air gap. If a low voltage operation is necessary, then the diaphragm fulfills the job by charging the surface constantly.



This operation has two techniques. The first technique is choosing the conductive coating of the diaphragm and applying in a manner, so that it can be given a high surface resistivity. The second technique is placing a series of large value resistor in between the diaphragm and the EHT power supply. EHT power supply means Extra High Tension or voltage power supply.

A polyester film is normally used to make the diaphragm. These polyester films have brilliant mechanical properties. Pet films can be a good instance of this kind of films. The diaphragm is held at a DC potential of a high range kilovolts. Audio signals are used to make the grids work. Front and rear grids are antiphase driven. And as a result to this an electrostatic field, which is proportionate to the audio signal is being produced. And it is being produced between both grids. And for this reason a force is exerted on the diaphragm when it is charged. And it causes a movement that sends the air on its either side.

Electrostatic speakers have some facilities. Firstly, it has a diaphragm, which is absolutely light weighted. Secondly it has got a good frequency response.

The history of electrostatic speakers is very interesting. It first came out during the phase of 1920. But at its initial stage it was not that much reliable. It had a lot of problems in its making. That time it was surrounded by problems like low efficiency, unwanted discharges etc.

And as an inevitable result of these loopholes, it started loosing its market. It completely took a backstage when other kinds of chip and better quality speakers emerged. This story went on till 1950, until new materials like polyester plastics came up.

After the emergence of these materials, electrostatic speakers got back its previous position. And this time it was more prepared and technically well built. As time moved on this speaker kept on changing its look. Now they look smart, trendy and are packed with loads of modern technology.

There was a famous accusation for these kinds of speakers. It was said that though these speakers are good for classical music, but they lack bass effects in rock music. But times they are a changing. The modern electrostatic speakers provide a lot of facilities. They have got a good and tight bass effect.

One thing about these speakers is they are a bit expensive. But it has got a proper justification also. It provides you a lot of facilities and modern technology and they are made with utmost precision. Just because it is so useful, it is expensive. But I do not think you will mind to spend a little big amount for a long lasting, useful accessory.