Eminent Technology LFT-8b in Harry's system


I recently signed up for the V.P.I. Industries newsletter, and today received my first such. In it, Harry Weisfeld reviews a Grado phono cartridge, but this post concerns one of the speakers he listed as being those he uses to listen to music and evaluate recordings through. All but one are traditional dynamic cones/domes in a box designs, only one being a planar/dipole. That planar is the Eminent Technology LFT-8b. I'm pretty sure Harry could, if he so chose, have instead as his sole planar a pair of $6000 Magneplanar MG 3.7i's, or even $14,000 20.7's. But nope, he instead chose the $2500 ET LFT-8b, imo the greatest value in a loudspeaker on the market. I compared it to the 1.7i, and the difference was dramatic.
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aniwolfe, why the ET's aren't as commonly owned or even discussed as are Maggies is a mystery to me. The 1.7i with the essential Mye stands cost more than does the LFT-8b with Sound Anchor stands, and are simply not as good a speaker (okay, imo). The ET's make the 1.7i sound "wispy", lacking tonal density and body. The ET's magnetic-planar driver covers 180Hz to 10kHz, without a crossover! The dynamic woofer goes lower than the 1.7, the speaker plays loud enough for R & R and Symphony Orchestra, and with less power required than the Maggie. The single highest value product I know of, and almost no one owns them. Weird!
You might also want to add the LFT8b’s sound much better than the 1.7 at lower listening levels as well.

You know I think Bruce is ok having a small company and being able to provide great customer service. He makes upgrades to his products if he feels its substantial enough.

I have to admit I am happy he doesn’t come up with a new version of the LFT every few years. That would drive me crazy and it would turn me off.

I like how he came out with the new tweeter years ago and all his customers had to do was just replace it by unscrewing it. No soldering involved...easy! That tweeter upgrade really made a huge difference.

Good point about the LFT-8b maintaining it's resolution at lower level/volume. It's more like an ESL than a magnetic-planar in that regard. That Maggies need to be cranked to a certain level to fully "open up" is widely acknowledged, being somewhat veiled and opaque at low levels. That is another reason the LFT-8 is better for a smaller room than are the Maggies. I love Maggies too (my first high end speaker was the original Tympani-I, and I now own a pair of Tympani-IV's and IVa's), but they really need a bigger room than does the LFT-8b.

The fact that the LFT-8 has been in production for twenty-five years, and has had only two revisions---a change of the woofer and the tweeter, both retrofitable to the first LFT-8 ever made, and at nominal cost---speaks to the "correctness" of it's design. The recent Magnepan "i" revision can not be performed on the 1.7, which must be a real drag to owners of that fine speaker.

The LFT-8's magnetic-planar midrange driver, which as has already been stated covers the frequency range of 180Hz to 10kHz (without a x/o, the entire midrange and all but the top octave reproduced by a single driver!), has remained unchanged in all that time. As has the x/o and woofer box. The m-p driver and ribbon tweeter are bolted onto a metal frame, while the Maggie drivers are glued onto an MDF frame, which exhibits some flex and resonance, hence the need for the Mye stands. Big difference!

All the LFT-8 needs is the revolutionary Eminent Technology TRW-17 Rotary Woofer. Unlike the LFT-8, however, it ain't cheap! 

bdp24, Really 120 db at 0 Hz?  The sound of silence.

The LFTs are somewhat like my Beveridge panels in their principle of operation, except the Bevs work on high voltages provided by the Beveridge amplifier, rather than on electromagnetic forces. (Unlike a classic ESL, the Bev mylar diaphragm is low impedance because its coated with aluminum; the amp drives both stators and the mylar. There is no static bias voltage on the Bev diaphragm.)

Ha! Hyperbole on my part Lew, obviously. But close to it (let's say 120dB @ 1Hz ;-), the Rotary Woofer not being constrained by physical excursion like mechanical transducers. A really fascinating, revolutionary, visionary creation from the mind of the brilliant Bruce Thigpen.

You have Beveridges, Lew? Another visionary product, with direct-drive amps for the ESL drivers designed by Roger Modjeski of Music Reference. I'm green with envy!