Eminent Technology LFT-8c Robert Greene review

@ledoux1238 

From the couple of videos from last year Florida show, the 16s looks really interesting. It uses the ribbon tweeter and mid-range panels with upgraded magnets in one panel and a seperate bass unit with six or seven dipole 6" woofers, The thing I don't like is that it will be completely active, no amps required. I like tubes. But that may be a bias I can get over. 

I just send Bruce a question on the status of the 16s' . 

Iv'e listened the the LFT-16s at least ten different times close to 5 different amplifiers [at least] over a period of years at my local dealer.  All sessions were either different AudioNote or Quicksilver TUBE amplifiers, 10w, 20w, 60w, 120w versions. 

Two sessions they were powered wtih my same Quicksilver Mono 120 amplifiers with KT150 tubes in the amps both times.  I liked the 16s so much with my own amplifiers I was so darn tempted to buy them just to have them for their cost, sound, value, small footprint.  I did not need another pair of speakers, and build my own speakers, yet these are something different on their own.  Each time, the speakers were pulled out into the room about 7' from the front wall, and did not need a subwoofer when matched with my amps.  Really neat little speakers, and fun to listen to, fwiw. If you are dead set on getting a pair, I could ask my local dealer if he still has a few sets.  He used to keep a few in stock as they sold fast or people would some time trade them back to try the larger unit 8bs.  I always enjoy listening to them when he had them fired up whenever I stopped by.   

My apologies for confusing the various models from Eminent Technology.

The newest model speaker which @audibleguy referred to is indeed 18SL. The LFT-16 is the smaller brother of LFT-8s, and apparently Bruce will not be making more of those. What  I wanted to ask Bruce was the status of 18SL. I’ll send another email asking about the new model.

How come 83 dB sensitivity with a powered low end? I’d love to try a pair of these but only run 60 watts.

@howardlee 

Although there is no information on 8c’s sensitivity . The 83db sensitivity refers to the 8b’s. Bruce mentioned in an email that 8c has 86 db sensitivity. And he has customers running SET amplifiers with the 8c provided that  listening level was below 90db. 
 

I had paired a 20w push-pull tube amp by Mactone Audio with 8c and it was perfectly fine as far as listening levels was concerned. 60w should be plenty. 

Everyone is of course entitled to their own opinion on the question of accepting the digitization of the entire signal when moving from the LFT-8b to the -8c, rather than just the frequencies sent to the woofers (low-passed at 180Hz with 1st-order filters). I myself am not willing to make that sacrifice. And beside which, there is a better alternative: the Rythmik Audio/GR Research OB/Dipole Servo-Feedback Subwoofer.

Using dipole woofers with dipole speakers is of course a good idea (Wendell Diller of Magnepan has for years stated that non-dipole woofers "Do not work" with dipole speakers, period. You are free to disagree with him).

The LFT-8c adds a 6.5" rear firing woofer to the front firing 8" of the -8b, still in a sealed enclosure (so not an open baffle design). The Rythmik/GRR sub is comprised of a pair of 12" woofers mounted in an open baffle frame, and powered with a Servo-Feedback amplifier. To add the OB/Dipole woofer to the LFT-8b, just leave the 8b’s stock woofer disconnected (it has its own binding post), and use the OB/Dipole in its place. The sub amplifier includes all the x/o controls (non-digital) you need to use it with any speaker you want. Unlike "normal" subs, the OB/Dipole plays up to 300Hz, well above the 8b’s x/o frequency of 180Hz. And with no digitization of the signal, at any frequency.

In my opinion, adding the Rythmik/GRR OB/Dipole Sub to the LFT-8b is a better choice that replacing the -8b’s woofer with the woofer system of the -8c. You are free to disagree

By the way, the LFT-8b, while tall (5’), is otherwise not large: only 13" wide and deep. The Sound Anchor stands are in most users opinion mandatory, which adds a few inches to the front of the speaker. ET sells the SA stand, and ships them along with the speakers. And of course all dipoles need to be at least 3’ from the wall behind them anyway (5’ is better).

As for power, though very low in sensitivity (83-84dB), the LFT-8b does not require the kind of amplification Maggies do. The -8b is a very even 8 ohm load, the Planar-Magnetic panels themselves 11 ohms. Use the OB/Dipole Sub in place of the stock woofer, and you are free to use any moderately powered tube amp you want. The Music Reference RM-9 and -200 work splendidly.

I miss being able to listen to music through my Magneplanar Tympani T-IVa (they’re far too big for my current music room (only 13’ deep and 14’/4" wide), but the ET LFT-8b’s midrange is actually superior to that of the T-IVa. And the Rythmik/GRR OB/Dipole Sub is the closest I’ve heard to providing the bass quality and character of the amazing twin Tympani bass panels, each panel 16" wide and 6’ tall. Now THAT’S a big woofer!

As for the problem of comb filtering issues between the midrange driver and the tweeter (the wavelength at 10kHz is VERY short), the speaker may be rotated to minimize any phase cancellation between the two drivers you are experiencing. I wonder why Thigpen chose such a high x/o frequency?.