Steve Guttenberg finally reviews the Eminent Technology LFT-8b loudspeaker.

For the money they are decent but very inefficient even more so when you consider 

most quality amplifiers double their power or close to into 4 ohms .

these speakers are only 83 db efficient at 8 ohms  , needing a pretty power full 

amplifier ,and cannot compete with the 3.7 which has a excellent separate tweeter panel, at 2x the cost though it should be much better.

eminent i belive is long time company before 1980 ,, just wonder the now  make good speaker? anyone have ever hear beside Steven G.  ,, i must confess that the more opinion about this speaker ,  thr more i maje a good conclusion about quslity on yhisv speaker  ,,, anyone can help me about this transiator https://youtube.com/shorts/zRakw_KIfWI?feature=share   thanks everyone who have answers my question!

Excellent Ric (@ricevs), thanks; I hadn’t seen those videos. For those who don’t know, Ric at EVS was in the past offering a line of loudspeakers employing NEO planar-magnetic drivers mated with the fantastic open-baffle servo-feedback woofer offered by Rythmik Audio in conjunction with GR Research. I have a pair of the OB subs, with two woofers in each W-frame I built from flat pack kits.

By the way Ric, I still have the Audible Illusions Modulus 2 pre-amp you "modified" (redesigned is more apt ;-) for me back in the 90’s ;-) .

Exactly as @aniwolfe states. Looking at the impedance versus frequency chart on the ET website, you’ll notice the impedance of the LFT-8b remains above 10 ohms all across the spectrum, with the exception of dropping below 10 ohms only between 55Hz and 180Hz (the crossover frequency). Unlike Maggies, a good candidate for tube amps. I had already sold my pair of Atma-Sphere M60’s by the time I got the ET’s, but I’m sure they’d work great, especially on the m/t panels themselves (with as I said above ss on the woofers). In contrast, Maggies never rise above 4 ohms, dropping sightly below 3 ohms at some frequencies.

As far as sensitivity goes, we have to keep in mind that sensitivity measurements are always lower with dipoles than they actually perform in a room. Those measurements ignore the back wave, fully half the speaker’s output! Add 3dB to the stated figure. Still low, but not enough so to cause it to be extremely amplifier-fussy, unlike ribbons, which are low in sensitivity, low in impedance, and reactive in nature (magnetic-planars are pretty much a resistive load). That is why I cringe when I hear Steve (and others) characterize Maggies as quasi-ribbons. No, they’re not. They are planar-magnetics, with the exception of the Magnepan true-ribbon tweeter. The tweeter in the LFT-8 (reproducing the top octave only---10kHz and up, though with a shallow 1st-order high-pass filter) is also a ribbon, the midrange driver a planar-magnetic---as Steve mentions, push-pull in design (most of the Maggies are single-ended.).

@aniwolfe Sensitivity is low but it does not require a high current amp. This speaker will not go lower than 7 ohms. So lower powered tube amps work fine if not used in a large room, needing concert listening levels. The LFT’s are especially sensitive to VOLTS = Tube power.

I’ve heard the LFT-8bs paired with a very capable 10w AudioNote EL34 amplifier, and a 20wpc QS Integrated. While it sounded nice at low volume levels, in a 12x25’ room, sitting about 8ft away, the speakers tended to lose their steam and dynamics above 1/2 volume level on that AN integrated. A little better on the QS 20wpc integrated. Still needed a little more boost, even for low volume listening levels, imo. Now jumping up to higher power 60wpc+ QS Monos, separate/active tube preamp, yielded larger and more expansive sound. I found the 8Bs seemed to thrive better at lower listening levels with a little more power and drive behind them, for whatever reasons.

Given the chance, once the 8Bs are back in stock at my local dealer, I’m gonna ask to hear them on the Audio Note Meishu Tonmeister 300b amp. While its only 8w, still a capable amp, speaking of current, impedance/match, capability to drive. Might be a few months, hope to try it next to see & hear the pros/cons.

@bdp24 Thanks. That's helpful!

@ozzy

Sensitivity is low but it does not require a high current amp. This speaker will not go lower than 7 ohms. So lower powered tube amps work fine if not used in a large room, needing concert listening levels. In contrast you need a High Current amp for Maggies which suck at low listening levels.

The LFT’s are especially sensitive to VOLTS = Tube power.

https://www.eminent-tech.com/images/lft8bgr/impvfreq8b.jpg

check this out:...active...triamped.....room correction....optionally you can use your own amps on the mids and highs.

https://www.youtube.com/watch?v=91ybrCypcKk&t=592s

https://www.youtube.com/watch?v=LjliBC6Z95s

Did I read the specs correctly? Sensitivity 83db? That seems pretty low for tube amps. But again, speaker specifications still confuse me.

ozzy

@hilde45: While the LFT-8c is an advanced version of the LFT-8 in terms of low frequencies and room correction (it contains DSP), the -8b remains available. Not everyone may want or need what the -8c offers, the -8b being a cheaper and sufficient alternative 

These are on my shorter list to try. Thanks for the head’s up.

It's a shame he reviewed the 8b. There's an 8c now. https://www.eminent-tech.com/LFT8.html

You’re correct @aniwolfe, Steve didn’t mention just how wideband the midrange driver is: it does 180Hz up to 10kHz, crossover free within it's bandpass! For a small room the 16a would be a nice choice, though you still need some space between it and the wall behind it.

A good suggestion @decooney. I can recommend both the RM-9 Mk.2 and RM-200 Mk.2 Music Reference amps, which put out 125w/100w (respectively) into 8 ohms. If you bi-amp (the dual binding posts make that fairly easy)---with a tube amp on the panel (the m/t panel presents an 11 ohm load to the amp) and a 100w ss (it need not be expensive, just good) on the woofer, that is probably all you need for just about any size room, program material, and listening level.

You will be rewarded with a loudspeaker in the same league as many ESL’s in terms of transparency, but with greater maximum volume (I also own the Quad ESL), besting all the Maggies except that company’s fantastic ribbon tweeter (contained in the Tympani T-IVa, and current MG3.7i, 20.7i, and 30.7). Ans without the Maggies’ lack of dynamics and resolution at low listening levels.

For dipole planar lovers, it’s a heck of a loudspeaker package! That it has remained such a well-kept secret for so long has been a mystery to me for years. Another factor that led me investigate the LFT-8b was reading what Harry Weisfeld of VPI had to say about; he said he considered it’s midrange reproduction the best he had ever heard, from any loudspeaker, at any price. I don’t know if I’d go THAT far. ;-)

A few years back while auditioning my current pair of Quicksilver Mono 120 amplifiers with KT150s installed, they were paired up with the smaller LFT-16a speakers. The room and speakers were set up nice and it was very enjoyable. At that moment I remember saying to myself, man this is all anyone needs in a smaller listening room setting. I’m not sure they’d do as well in a larger room at higher volume levels.

Prior to that heard the I’ve heard larger LFT-16a speakers set up and playing at my local dealer many times. Sometimes paired with various lower powered amplifiers too - Quite surprising how well they sounded at lower volume levels for such inefficient speakers, in the low 80s. Look at the impedance of these speakers to learn more.

I tend to believe they can do their best when paired with a proper set of mono block tube amplifiers with quality iron behind them. I kinda liked them paired with higher power 60wpc+ push-pull tube amps vs lower power tube amps. That could just be me, or my taste. I have yet to hear them paired up with high quality Class-A solid state amp(s). Would be great to hear from others and what SS amps they’ve used with them, and compared running them with various tube amps. What were the results - if anyone here has stories to share about different pairings with ETs?

Long Live the ET LFT8b’s!! Owned them for 12 years. Something I am not sure Steve mentioned, the Midrange Panel tackles 100hz to 10k. Which I think its very impressive to be honest.

Thinking of buying the LFT16a’s.