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Power Requirements: 100 watts minimum
Sensitivity 83 dB (pink noise, 20-20 kHz)
at 1 watt/1 meter (2.83 V)
Frequency Response 38 Hz-20 kHz ±4 dB (typical
room, close-mic measurement)
-10 dB at 35 kHz
Phase Accuracy ± 20° 100 Hz-31 kHz
High Frequency Level Flat, -6 dB, -12 dB at 20 kHz
smooth rolloff
Impedance 6 Ohm rating
Maximum SPL 105 dB at 1 meter
Magnet type Ceramic 8
Diaphragm Area 420 in2 (front)
Harmonic Distortion Less than .04%, 100 Hz-20 kHz,
90 dB, 1 meter
Dimensions 18" wide by 78" high by 1"
thick
Shipping Weight 95 lbs. each
Foil thickness .00033"
Mylar thickness .0005"
Laminate Adhesive Thickness .00015"
Gap Between Conductors .03"
Peak-to-Peak Diaphragm .4" Woofer .035 Tweeter
Displacement
Warranty 3 years parts, 1 year labor
Finish Oak standard
Walnut and other painted
finishes optional
Music All of the above done for the
enjoyment of music.
Designers David Collie and Bruce Thigpen
To fully understand the strengths of the LFT design, one must
first consider the design and operation of this speaker's three
most notable antecedents: the push-pull electrostatic loudspeaker
(ESL); the traditional, single-ended planar magnetic loudspeaker,
and the ribbon loudspeaker.
By applying such new techniques to planar loudspeaker construction,
Eminent Technology has been able to eliminate many of the flaws
inherent in earlier designs. The use of a welded channel-and-crossbar
frame dispenses with the need for perforated sheet metal (an ìoff-the-shelfî
material presumably used for reasons of economy and ease of manufacture.)
thus greatly improving dispersion, especially at high frequencies.
Since it is now possible to have a powerful, precisely aligned
magnet structure on both sides of the diaphragm, true push-pull
operation has been achieved: Regardless of the degree of excursion
the diaphragm undergoes, the voice element is always optimally
positioned within the magnetic field. The result is extremely
linear performance throughout the audible range, with a profound
increase in dynamic range and an absolute minimum of distortion.
Each LFT-VII has five individual driver panels. The outside portion
on each panel is divided into separately driven bass and (line-source)
midrange areas, with the former operating from 400 Hz down, and
the latter operating from 400 Hz up to 10 kHz. The tweeters operate
as a line source from 10 kHz up to and beyond 20 kHz. The midrange
and tweeter sections are distinguishable by their thinner magnet
structures.
All three panels operate as woofers, from 400 Hz on down. Actually,
all of the panels, including the woofers, are physically
capable of operating to beyond 20 kHz, but would exhibit undesirable
diffraction effects and poor dispersion if allowed to do so, which
is why the panels are segmented into different sections for different
portions of the frequency range. The use of a flat panel design
maintains excellent phase response throughout the audible range.
LFT Impedance
The LFT-6 can be made to operate at almost any impedance; our
present choice of a nominal 6-Ohm impedance has been made in the
interest of maximizing efficiency and amplifier compatibility.
Because of the large surface area of the panels and the resulting
good heat dissipation (a function also of the material choice
for the voice grid), the LFT-6 can handle tremendous amounts of
power before any risk of damage.