Specifications

Eminent Technology’s Linear Field Transducer, introduced

as the LFT, represents a new approach to the design and

construction of a high-quality loudspeaker*. It builds on the

strengths of the above designs while eliminating many of their

drawbacks.

The construction of the LFT –8b begins by laminating a very thin

sheet of aluminum foil to a half-mil-thick sheet of Mylar. A voice

grid pattern, created by means of CAD (Computer-Aided Design)

technology, is silk-screened onto the foil side; the remainder of

the aluminum--the part not covered by ink from the silk-screening

is chemically etched away, in a manner similar to the etching of

traces on a printed-circuit board. The ink is then washed away,

leaving a voice grid of near-perfect uniformity. This technique

results in a diaphragm/voice coil grid that is still less than one mil

in total thickness, and also permits relatively narrow spaces

between the individual traces, so the diaphragm can be evenly

driven over its entire surface.

The magnet/frame structure developed for the LFT-8b is also

unique. Eminent Technology builds its strip magnets into

individual steel channels, the size and shape of which have been

carefully designed to help “focus” the magnetic flux lines and

concentrate the strength of the magnetic field on the appropriate

area of the diaphragm/voice grid. These channels are then welded

to steel crossbars, which in turn are bolted to the frame that holds

the diaphragm in place.

Interestingly, one of the biggest challenges faced in creating a true

push-pull dynamic speaker was not a design consideration but

rather a matter of construction difficulty: to assemble a perfectly

rigid structure with very powerful permanent magnets at the front

and the rear, both sides opposing each other with tremendous

force. It was not until Eminent Technology developed a special

method for this assembly procedure that the Linear Field

Transducer became a reality.

* The design and construction of the LFT is patented.

The Linear

Field

Transducer

Diaphragm

Construction

The

Magnet/Frame

Structure