Martin Logan Speakers – A Look Into Electrostatic Speaker Design

Martin Logan speakers have an architectural beauty that in our opinion cannot be matched by the traditional box loudspeaker. Electrostatic speaker designs have existed for over 100 years. American Manufacturers Martin Logan have taken this technology and spent the last thirty years refining it to produce the state of the art loudspeakers. Early electrostatic designs were renowned for their accuracy and coherence but also had inherent problems. They were harder to drive than box speakers and therefore needed more powerful amplifiers to drive them. They also struggled to reproduce deep bass and the sweet spot for listening was quite narrow. Despite their drawbacks however, electrostatic panels were often preferred by music lovers because of their aforementioned accuracy. Preserving everything that electrostatic panels did so well, while ironing out their limitations became the goal at Martin Logan

UNDERSTANDING THE DESIGN OF THE MARTIN LOGAN ESL PANEL

The key to the quality of sound reproduced by any piece equipment, be it a Luxman amplifier or Martin Logan speakers, is the attention to detail incorporated into every aspect of its design. Each Martin Logan ESL panel contains an ultra-thin, low mass diaphragm. That moves backwards and forwards pushing the air to the listener. The diaphragm is held between two electrically charged metal stators, the perforated grilles. These stators receive the music signal from the amplifier. There are also spars, they stop the diaphragm's excursion before it hits the stators. A Martin Logan panel loudspeaker is essentially one large vibrating diaphragm.

A - Diaphragm
B – Spars/Spacers
C - Stators

The diaphragm receives a positive electrical charge from the mains. The front and back stators receive their charge from the music signal. One will be positively charged and the other negatively charged i.e. opposites but the level of charge will always be equal. When the rear stator has a negative charge it pulls the diaphragm towards it. At the same time the front stators positive charge pushes the diaphragm away. The diaphragm follows the music waveform as the charge in the stators flips back and forth, positive to negative causing the diaphragm to travel back and forth. This mimics the changes in air pressure from the original musical signal.

The lightweight diaphragm in the Martin Logan ESL speakers can respond very quickly, without lagging behind the original signal. There is extremely low phase distortion, again emphasising accuracy.

Crossover Design On The Martin Logan Electrostatic Speakers

One of the most difficult aspects of speaker design is creating one that can deal effectively with the full audible frequency range. Speakers that do not achieve this can provide poor quality sound, that can lessen the listening experience.

Crossovers take signals from an amplifier and split them into high and low frequencies sending the appropriate frequency to the relevant driver. Ideally there wouldn't be a crossover to add complexity to the signal path. A single driver would handle all audible frequencies from covering 20HZ to 20KHZ. The problem is no speaker can achieve this. The Martin Logan approach is to crossover in a non-critical area of the audio spectrum. i.e. below the critical midrange (2000 - 5000 Hz). Crossing over in the mid band can add colour to the sound.

The beauty of the large Martin Logan Electrostatic speakers is that they can reproduce frequencies from above the range of human hearing right down into the bass area. The bigger the panel the wider the frequency range it can cover. This allows the speakers to cross over at around 250 hz. At this point the electrostatic panel hands over to traditional bass divers.

This hybrid design then combats one the traditional electrostatic panel weaknesses, lack of bass. This is just one of the many reasons why Martin Logan speakers review very well. They also win numerous awards for quality, design and sound, most recently they were awarded as a Hi-Fi News ‘Highly Commended’ product.

WHY MARTIN LOGAN ELECTROSTATIC SPEAKERS PROVIDE BETTER SOUND

Traditional cone speakers can have very wide dispersion in all directions. The dispersions then reflect and lead to all kinds of dispersion patterns around your room. An electrostatic panel has more surface area than a cone. The advantage of this is you have a more controlled dispersion. Sound is more directional and therefore less reflective. To stop the panels being overly directive Martin Logan introduced their curvilinear panel. The stators curves at about 30 degrees, this widens dispersion beyond a narrow beam. This increases the ideal listening position without being hugely reflective from the side walls.

Martin Logan Electrostatic speakers are dipole in their design and this also controls dispersion. Sound waves travels backwards as well as forwards. The sound emitting from the front is in phase, from the back out of phase. The positive and negative waves cancel each other where they meet at the sides. If you listen to a Martin Logan panel from the side it is very quiet indeed.

Martin Logan Electrostatic ESL speakers are an extremely musical transparent loudspeaker. The Hybrid design extends the bass, the curvilinear panels increase the listening area. A long standing speaker design has been improved and elevated to classic status.

Martin Logan Speakers On Demo At Fanthorpes HiFi, Plus More!

Fanthorpes HiFi stock an extensive range of Martin Logan’s. The entry level speakers are part of the Electromotion range of panels. We have the starter panels, the Martin Logan Electromotion speakers and the step up the Electromotion X. Moving on from here we enter the Martin Logan Masterpiece series. We have the entry level Panels, Classic 9, which then steps up to the Martin Logan Impression 11A.

Our demonstration range is topped by the amazing Martin Logan Renaissance 15A. We have one of the largest collections of Martin Logan speakers on demonstration in the country and we welcome you to our store to audition them. If that is not convenient please contact us about the possibility of a home demonstration. We install extensively around the country and will be happy to arrange a demonstration with you. For more information call us on 01482 223096 or email [email protected].

At Fanthorpes HiFi, we love to trade in, so if you want to trade in your existing HiFi against Martin Logan’s then contact us and we will let you know what it is worth as a trade in. We can also offer finance on the balance of the purchase.