Quick Facts

The original machine for curving stat panels was nicknamed 'the pig trough'.

Slang used over the years to describe machinery or processes in the stat panel room include: the donk-u-lator, kazoo, Frankenstein, bounce, spoo, bleen, nerney, and slurry.

"Stat Panel Hell" was an environmental testing chamber used to rapidly age panels during the development of the XStat.

MartinLogan maintains the tools and resources to build new stat panels for nearly every electrostatic speaker we've ever released (our first speaker shipped in 1983). Can you think of anything else you purchased in 1983 for which you can obtain newly manufactured factory parts?

Electrostatic Panel Assembly

The heart and soul of MartinLogan speakers.

The heart of every MartinLogan ESL Series speaker is a see-through electrostatic panel, comprising an extremely low-mass, coated-polymer diaphragm sandwiched between two curved sheets of perforated steel called stators. This proprietary Curvilinear Line Source (CLS&tsrade;) design has earned a U.S. patent and many awards—not to mention a lot of nice comments from our customers.

Building a MartinLogan electrostatic transducer.

Stator fabrication is a lengthy process that involves more than 100 steps (including some that are closely guarded trade secrets) and extensive labor. It starts with a custom tool that punches a distinctive pattern of many small holes in a steel sheet. We then coat the perforated metal with a Nylon insulator and fire it in a huge oven at over 575 degrees Fahrenheit to fuse the Nylon directly to the steel. This not only provides critical insulation but also eliminates the need for a grille cloth, which could degrade sound quality. Each stator is arc tested to 10,000 volts (twice the panel's working voltage). The next step is to form a pair of stators into a 30-degree arc, which provides a curved armature for the diaphragm and, in turn, MartinLogan's signature Curvilinear Line Source sound dispersion.

The ultra-light, 0.0005-inch-thick polyethylene terathylate (PET) diaphragm is plasma-deposited with a conductive coating in a $20-million, oxygen-free argon environment chamber. This ensures extreme consistency across the diaphragm surface and enables it to accept high voltages without danger of arcing.

In the most time-consuming and delicate process of all, the finished diaphragm is stretched over multiple spacing elements (called spars), which hold it at a precise distance between the two stators. The final step is attachment of the electrical power supply and signal connectors.

Building a MartinLogan electrostatic transducer.

One of the most notable production steps in XStat assembly is a proprietary vacuum-bonding process. Each fully assembled panel is placed inside a flexible vacuum chamber that compresses it evenly across its entire surface, assuring ultimate consistency across every square inch.