We are very pleased to announce that we are now stocking the new Martin Logan Electromotion Electrostatic loudspeakers. These use electrostatic panels rather than conventional dynamic drive units to produce the mid-range and high frequencies.

How an Electrostatic Works:
Electrostatic loudspeakers comprise of three basic components - Stators, diaphragm and Spars all assembled as a sandwich structure. The diaphragm is an electrically conductive plastic film that is stretched taught between the stators. The stators are are perforated steel sheets coated with an insulator. When in operation the diaphragm is charged to a fixed positive voltage by a high voltage power supply. (This is why all electrostatics are mains powered). The stators are connected to the speaker outputs of the amplifier via a step-up transformer. This converts the amplifiers output to a pair of high voltage signals of equal strength but opposite polarities. As the positive charge in one stator grows the negative charge in the other grows an equal amount. As like charges attract and negative charges repel the positive charge on the diaphragm will force it to move forwards and backwards depending on the charge. Therefore the stronger the charge the greater the movement and produces the movement of the diaphragm normally seen in a conventional drive unit. To help stiffen the panel and prevent the diaphragm from coming too close to the stators non conductive strips called spars are placed along the length of each panel.

The Benefits of an Electrostatic Loudspeaker:
Conventional loudspeaker drivers use a cone attached to a voice coil; the centre of the cone is only being driven and the rest of the cone is just following along. This means the cones have to be made as rigid as possible creating additional weight. The tweeter however needs to be as light as possible to enable it to achieve higher frequencies. Electrostatics overcome this as the diaphragm is driven across its entirety so it does not need to be rigid and can be made of an exceptionally light material. This enables the panel to produce sonic details with exceptional precision. The panel can operate over an exceptionally wide frequency response which eliminates the need for a crossover network between the mid range and the tweeter. Conventional loudspeakers can have the the problem of cabinet colouration and there will always be an effect on the drive units from the cabinet. This is eliminated in the mid to high frequencies of an electrostatic as there is no cabinet. Another key benefit of an electrostatic is that it operates as a true dipole. This enables them to offer exceptional clarity and an astonishing deep open sound stage.

The only drawback to the electrostatic is that they cannot reproduce the deepest of bass sounds. Martin Logan have overcome this by utilising a hybrid design. The very lowest frequencies are reproduced via a very high quality dynamic woofer. These are crossed over to the electrostatic panel via a carefully tailored cross over network. The critically damped woofers used ensure a seamless transition between the two types of drivers.

Electromotion ESL:
The ESL incorporates an Xstat Electrostatic panel with a total radiating area of 129 square inches. The panel is coupled with an 8 inch high excursion doped fibre coned woofer designed exclusively for the ESL. The lightweight cone achieves remarkably low distortion levels allowing seamless integration with the electrostatic panel. Connection to the amplifier is via high quality binding posts and the speaker is supplied with heavy duty spikes allowing tighter coupling between the speaker and the floor.

Electromotion ESL-X:
The ESL-X features a larger electrostatic transducer and utilises dual 8 inch woofers. The Xstat panel has a radiation area over 50 inches larger that the ESL and is coupled with two 8 inch doped paper high excursion woofers housed in a non resonant bass reflex enclosure. This achieves a frequency response of 41Hz to 22kHz. Offering an easy load of 6 Ohms and power handling of 20 to 400 Watts.

Listening:
We have had the Martin Logans set up with numerous systems. These have included Naim ND5XS Streamer coupled with an Arcam A39 class G amplifier, Clearaudio Performance DC turntable coupled with a Unison Research S6 valve amplifier. In all the systems we have tried the speakers have provided exceptional mid range clarity and high frequency performance. The sound stage provided is almost holographic. There have been instances when you could not tell where the speakers were as the sound stage was so expansive that the speakers appeared to disappear. As a hybrid the integration of the bass is of paramount importance. To test this we played 'Drones' by Muse and they produced exceptionally deep and tight bass akin to a conventional high end loudspeaker. However at no time did you feel that this was at the expense of the open midrange and top end performance. 'Pacific Coast Highway' by Christopher Franke (Tangerine Dream) again has thundering bass with a very open midrange that at times just sounded truly astonishing. Vocals are also truly lifelike. We played Tracey Chapman 'Fast Cars' and the emotion portrayed in her voice was up there with the best I have ever heard. Classical music is somewhere these speakers really do excel, playing a string quartet the players are so well positioned you can place them to within inches to such an extent that you really do feel that they are in front of you. Full scale orchestra such as Shostakovich Symphony No 8 also has exceptional power and depth.

We really do feel that these speakers are capable of producing certain aspects of music that conventional loudspeakers find very difficult to attain. A demonstration is highly recommended.

Contact Jon and Farid, Audio T Cheltenham 01242 583960 to book your personal demonstration.