Eminent Technology LFT-8c Robert Greene review
A friend of mine forwarded this review to me a couple days ago. I hadn't seen it as it's just a week old at this point.
Why would I be interested? I have a pair of LFT-8b speakers that I picked up about 7 months ago. Wonderful speakers. I always wanted to try a set of panels and, as luck would have it, last summer I found a used pair of 8b's just a short drive from my home..I made the jump. As it turns out, this was one of the best moves I've made in my 50+ year audio hobby.
In the last few months, I was considering picking up the 8b to 8c upgrade components, but put it off as I had a number of other projects going on. Well..the projects got completed and I started a few more projects, though this time around the 8c upgrade is one of them. I ordered the 8c upgrade yesterday and I'm really looking forward to the adventure once it arrives.
One thing I've noticed when reading discussions of the LFT-8(no a, b, c) here on A-gon, is the discussion wanders over the now 36 year history of the LFT-8. Issues identified in this or that review from 10-20-25 years ago are brought up as if they reflect what the LFT-8 is today. LFT-8's had a great sound 30 years ago, with a few flaws, as any 30 year old speaker would, and it sounds better today. Nothing surprising there. Most companies cut ties with models as they age and come out with something new, whether they are really new or repackaged parts..that varies..
What's my point? I just find it interesting that Bruce Thigpen (Eminent Technology) came out with the LFT-8 in about 1990 and has been continually improving the model 8 year after year, decade in and decade out, staying in business with no advertising, though with a few shows here and there. There are very few current speakers(let alone businesses) alive today that have a 30+ year history under largely the same name. (Though the Vandy 2 series comes to mind) Pretty unique in this industry. It's also pretty unique that a decades old pair of LFT-8 speakers can be upgraded to the current model at a very modest cost. And the upgrade is easily done by any owner.
So..the latest review:
https://www.theabsolutesound.com/articles/eminent-technology-lft-8c-planar-loudspeaker/
Robert Greene goes into considerable depth in his review, which is specific to the 8c version, though he's done an 8b review in the past. I'm glad it came out as it pushed me over the edge in ordering the 8c upgrade. I'm not getting any younger..time to give the 8c a spin.
One last note, I've read in a number of older and current reviews that the LFT-8 speaker placement is..finicky. I haven't found that to be the case at all. In the last 7 months I've experimented extensively with placement and they respond well to various setups. My current setup is about 115 inches between the panels (on center) and maybe 30 degrees toe-ed in from facing directly forward. Each speaker is 45 inches off the front wall(on center) and 38 inches from the side walls. I have a great soundstage and and equally great imaging. My tweeter panels are on the inside.
(...and no..I have no affiliation with ET..just a customer owning a used pair of the 2017 model 8b)
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. |
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?.
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@bdp24 It’s very nice to hear from you. I agree that with your solution, LFT8b with 8” bass unit disengaged + Rythmik / GR Research dipole 12” sub-woofer, there is no need to explore the LFT8c. The 12” woofers should provide a fuller and more expressive low end, which may also affect the frequencies higher up. The differences between your speakers and a pair of LFT 8c could be resolved if we could ever get the two in the same system for an A-B compare. I would be very seriously interested, not so much to resolve disagreement. But I am still very much intrigued with the DSP that Bruce chose to deploy in the 8c. And a compare with your all analog system would reveal something about the digital / analog divide. I have a feeling that we will hear how they differ rather than how one is superior to the other. Over on Audiokarma.org, there is a much longer thread dedicated to the LFT-8c. And a fellow there has done a very thorough optimization of the 8c through its various parametric adjustments. He has also integrated an additional pair of subwoofers to the 8C. And his feels that the SQ from his set up is the best he has heard. |
