Eminent Technology LFT8B’s reversing woofer polarity

@ledoux1238: Here’s what I would do:

Get yourself a pair of LFT-8b’s and live with them for a few months. If you then feel you want to get more out of them, address the reason for your dissatisfaction. Why worry about bi-amping when you haven’t yet heard the loudspeaker?

For the money it would take to add a good crossover and second amp, you could instead add a subwoofer or two. A "normal" sub, not the OB. In my opinion bi-amping will not provide as much improvement as will adding a sub or two.

The LFT’s weakness is the woofer: it limits the maximum SPL the loudspeaker can produce. Bi-amping will NOT change that, adding subs will. If you don’t want to go with the OB, regular subs are a good second best. Rythmik and GR Research both offer the F12: Rythmik with an aluminum cone woofer (F12), GRR a paper cone (F12G). If you desire more output, there is the F15HP by Rythmik. Or any good sub of your choice.

Even when bi-amping the LFT-8b, the stock x/o stays in place. Thigpen uses x/o parts that allow him to offer the speaker for $2499/pr. A real good way to upgrade the speaker’s sound is to build a duplicate x/o (using the stock parts values), but with premium parts. The x/o schematic is viewable on the ET website (and is included in the owner’s manual), and if you aren’t into soldering, a good tech can build it for you.

The OB Sub provides the improvements of both bi-amping and adding subs, as well as creating a full-range OB loudspeaker. That would be my first choice. But it's not for everyone, perhaps not you, ay?

Hi everyone

I just wanted to share something with everyone who owns LFT8B’s.

About 6 months ago I emailed Grant Vandermye (myesound.com) best known for making stands for Magnepan speakers among several others. I had his stands on my 3.7i’s and really liked them. I asked Grant if he made those same stands for the LFT8b’s and he said he did not. I asked him, would he consider making me a pair for the LFT8B’s and to my surprise he said sure, why not. He’s a really nice guy and a pleasure to work with. Long story short....

Six months later, with the help of friend we set them up yesterday and all I can say is WOW! I cannot believe the improvement. Anyone who owns these amazing speakers needs to hear these stands. The first thing that just hits you is how much more stable the instruments are within the soundstage. I could not believe the improvement. I am hearing background details on familiar albums that are mind boggling. Bass is much tighter and much cleaner. Midrange and the high frequencies are much more open. They are, in my opinion, a must hear. For the money ($560.00 usd pair incl shipping) it is a tremendous upgrade for not a lot of money. Enjoy!

Scot

Cool Scot, I’m emailing Grant to get a pic of the LFT-8b stand.

Is everyone watching Steve Guttenberg’s Audiophiliac Daily Show blog on YouTube? The latest has Steve and Herb Reichert discussing 300B tube amps and horn loudspeakers. But there were also two things said which are directly related to the LFT-8b.

1- Eminent Technology specs the LFT-8b as having a sensitivity rating of 83dB. That, according to one Audiogoner, rules it out as a loudspeaker worthy of consideration. In the Steve & Herb video, both emphatically state that sensitivity is a highly over-rated factor in loudspeaker design, and that what you really want is as high an impedance as possible. That is of course especially true with a tube amp, for the obvious reason.

The LFT-8b has a nominal impedance of 8 ohms (the Maggies---also a magnetic-planar design---are nominally 4 ohms, but dip to just below 3 at some frequencies). However, the LFT midrange and tweeter drivers, when separated from the dynamic woofer, present a constant 11 ohm load to the amp. A very good reason to bi-amp the LFT-8b.

2- Herb recounts a story of listening to the Altec A-7 and Wilson WATT/Puppy side-by-side in the late-80’s. He and his assembled guest listened first to the Wilsons, quite liking the sound. But when the Altecs were played, Herb says the "life-size" image they produced made the Wilson image appear as a miniaturized version of the same picture.

I have stated many times that I prefer planar loudspeakers over boxed ones for that exact reason (likening box speaker sound to a doll house), amongst others. When I hear a voice hovering about 3’ off the floor, my suspension-of-disbelief evaporates. The LFT-8b produces life-size images, and singer’s voices at life-like height.

Hi all

Regarding the amp requirements to properly drive the LFT8B’s, too many people worry about having enough watts per channel. My experience has taught me that the quality of the amp is much more important than the watts per channel.

I had a Cambridge stereo amp on them (200 wpc) and it was good. Not knocking Cambridge, they make a nice amp, but when I switched to the Pass Labs XA30.8 and heard it for the first time, I laughed out loud. That amp, on paper, is rated at only 30 watts per channel (solid state) but it’s all power supply. The thing weighs 84 lbs, it’s rated at 30 wpc @ 8 ohms, 60 wpc @ 4 ohms & 120 wpc @  2 ohms and it still has 12 dB of headroom! It’s a class a design. That amp drives those LFT8B’s effortlessly and always sounds incredibly musical. Watts per channel means nothing. 

bdp24

Thanks for mentioning the Audiophiliac show on YouTube, I’ll definitely check it out. 

Regarding the Mye stands for the LFT8B’s, I’ll bet he doesn’t have any pictures on his website yet, mine were the 1st pair he’s built. If you look at the pictures of the stands for the Magnepan 3.7’s you’ll get the idea, it’s basically the same stand. I’ll try to get a picture posted on this website (if Agon will allow it).

I also forgot to mention the most important attribute of the stands, the upright braces that attach from the back of the stand to the sides of the 60” panel. The upright braces prevent the panel from moving forward or backwards when the music is playing. HUGE IMPROVEMENT. To test the stability of the panel, I put my finger on top of the panel and tried moving it forwards and backwards, it felt like it was anchored to the floor, no movement whatsoever. The biggest benefit is image stability. The instruments within the soundstage are now precisely placed and pinpoint and rock solid. The improvement is off the charts. Background details are much better. Background voices are more intelligible. On familiar recordings you hear things you never knew were there. Everything is much more open. Like I said in my original posting, a must hear for anyone who owns these speakers. No negative, all positive.

I also prefer a Planar magnetic driver to any dynamic driver. It’s a simple matter of physics. The heavier dynamic driver will never start and stop as quickly as the planar drivers. I’ve owned Magico’s, Avalon’s, and the list goes on, some of them costing more than 10x the price of the LFT8B’s. I obviously prefer the LFT8 B’s. The fact that they only cost $2500.00 pair is a gift. Thank you Bruce Thigpen! Take care.

Scot

Scot,

very important information that  you are sharing. The flexing of the panels adversely affect sound quality. I believe retrofitting  vertical bracing to the sound anchor stands that I am using would be another solution.