The following review was published in The Sensible Sound, issue 47, Winter 1993. The Sensible Sound is published quarterly at 403 Darwin Dr., Snyder, N.Y. 14226. Subscriptions are available at $20 for four issues. All foreign subscriptions are available at $30 for four issues. Subscriptions are payable in U.S. funds by check drawn on a USA bank or international money order. VISA or Mastercard accepted for telephone or fax orders. Tel 716-833-0930, Fax 716-833-0929.

This review was written by Kenneth M. Duke. Copyright 1993 by The Sensible Sound and Kenneth M. Duke.

Eminent Technology LFT-VIII

The Eminent Technology LFT-VIII is a hybrid speaker that uses dipole panels for the midrange and treble and a cone woofer for the bass. The panel, called a Linear Field Transducer (LFT) is one of the unusual features of this speaker. It consist of a thin mylar sheet or panel coated with aluminum foil. Portions of the aluminum coating have been etched away, like a printed circuit board, leaving a voice coil pattern behind. This pattern was developed using CAD technology.

What sets the LFT apart from other speakers is the magnet setup. The magnets are in a push pull configuration, sandwiching the panel, unlike other panel speakers, which typically use a single ended design with magnets on just one side. The magnet assembly consist of steel troughs or channels, containing powerful magnets, securely bolted together to sandwich the panel and create a strong, focused magnetic field, which better controls the panel movement.

The magnet assemble is bolted to the frame, which in turn holds the panel. Eminent Technology points out in its literature that it is this precision assembly that made the push-pull arrangement practical. The frame holding the tweeter and midrange panels is bolted to two 60"-long L-shaped metal brackets with oak strips attached to their outside surface. This frame occupies about two thirds the length of the brackets, while the open lower portion of the brackets slip over the outer portion of the woofer box, which doubles as a substantial base for the speaker, and is held in place by wood screws.

Two metal rods attached to the bottom of the woofer box serve as feet. They have threaded holes at each end to accept the sharp-pointed screws that couple the speaker tightly to carpeted floor and can also be used to adjust the angle of the speaker. The assembled speaker forms a slender tower shape 13"w x 60"h and weighing 85 Lbs. Gray cloth covered grills are attached to both the front and back of the frame and work to give a finished look to the speaker.

The woofer box is a truncated pyramid That extends about 17" behind the panels at the bottom and 7" at the top, enclosing a relatively small .8 cubic foot volume. The 8" acoustic suspension woofer is mounted very near the floor, probably to take advantage of the bass reinforcement possible from such a location. The midrange panel driver operates from 180Hz-10Khz and the treble panel upward from 10Khz. The mid-driver is approximately 41.5h x 3.5"w (126 sq. in.). The treble driver is located to the side of the midrange and is about 18"h x 3/8"w (10 sq. in.). The panels are mirror imaged.

The LFT-VIIIs come as a semi-kit, with some assembly required. It took my son and I more than one hour to assemble them, with the major actions being to screw the panels and feet to the woofer boxes and to connect wires to the top of the woofers. This is not especially difficult, but does take some time.

The speakers are awkward to move, with significant weight concentrated at the bottom and the tall panel, attached only with seven screws not offering a secure place to hold on. Four jacks are located on the top of the woofer box and are easily accessible. These are high quality, heavy duty 5-way binding post set up for bi-wiring or bi-amping.

During the break in period, I experimented with placement of the LFTs in my room, as is necessary with all dipole radiators. The best position was similar for that of my Apogee Calipers - about 4' off both the back and side walls, 6' apart, with the tweeters on the inside. I tried a couple of toed-in positions, but settled for aiming them straight into the room.

The LFT-8 is a fine natural sounding speaker. The small woofer gives reasonable bass extension and power, although I do expect a bit more low end power from a speaker in this price range. More importantly, however, the bass that it there is tight and detailed, matching well with the panels. Mids are very natural and quite revealing of detail; indeed, I have not heard such detail in my recordings on many other speakers.

Played at normal volume, the LFT-VIIIs lack any significant coloration. I did find them sensitive to power levels- although they can play quite loud, they tend to sound metallic on massed strings when pushed hard. They retain some metallic sound even at lesser power levels, and this constitutes the only flaw I heard in its overall performance. I must note that the metallic sound I heard was only apparent on orchestral music. I was never aware or put off by this on pop or rock music. In my listening this problem was most apparent on older orchestral, such as Respighi's The Birds on Mercury Living Presence from 1957, where a large part of the metallic sound is in the recording. But it was also present on more modern orchestral recordings, albeit to a lesser extent.

Treble is nicely extended, with excellent detail. One especially nice attribute of the LFTs is the grainless background from which the music rises. This as much as anything contributes to their refined sound.

Imaging is open, boxless, and very natural. It breathes with the music with the image getting larger as the music gets louder. The speakers offer an excellent portrayal of depth. Solo instruments as well as sections of instruments are depicted in a realistic, three-dimensional fashion. The image is precise and instruments can be easily located. There is plenty of air, resulting in a spacious image when such information is recorded.

The LFTs were compared to my Apogee Calipers, a similarly priced dipole speaker (mine are not the newer signature version) using mylar panels throughout. I found the LFTs to be more analytical and detailed, revealing information that the Calipers cannot. The LFTs bass is tighter and less warm, while the Calipers bass goes deeper and is more powerful. Both speakers image very well and give a similar sense of stage width and depth. While not of high efficiency, the LFTs are more efficient than the Calipers and don't work my amplifier as hard. In this comparison there was no clear winner and certainly no loser. The are different, with each having some real strengths along with some flaws. Neither does anything poorly, and there are no fatal flaws.

I really enjoyed the LFT-VIIIs. They are well-made audiophile speakers that compete very well with others in this price range. I can recommend them highly for pop and rock music with a small caveat on massed orchestral strings and woodwinds, mostly with recordings that tend to be metallic. This should not be a major problem for most listeners: it wasn't for me. They perform especially well in the ability to reveal detail and to image. The woofer is very well integrated with the panels, a difficult task that few manufacturers have gotten right. The Eminent Technology LFT-VIIIs are well designed, well-made audiophile speakers that bear serious consideration if you are shopping in this price range. -KMD