Paul McGowan gets asked about rotary subs.

Paul McGowan of PS Audio has for years posted frequent (daily?) videos on YouTube in which he answers questions sent in by people from the world over. I just watched one in which he answers a question sent by a guy in India, inquiring as to why rotary subs are not more popular. Paul gets around to completely answering that question, but before doing so says this:


"The Rotary Sub was invented by a guy named Bruce Thigpen, and Bruce is a VERY (Paul’s emphasis, not mine) creative inventor who used to have a company---maybe he still does---called Eminent Technologies (sic. It’s actually named Eminent Technology). And Eminent Technologies, they made some GREAT (again, Paul’s emphasis) loudspeakers. They were---if I remember right---they were planar, or electrostatic---I think they were planars, they weren’t electrostatics, but they were REALLY (Paul again) good. And I don’t know what ever happened to that, but I DO know that Bruce figured out a way to make a subwoofer that could go well below what normal subwoofers do."


But this post is not about the Eminent Technology TRW-17 Rotary Subwoofer (there aren’t rotary "subwoofers", there is only one Rotary Subwoofer, the product of ET alone), it is about Eminent Technology itself. I mean geez, if Paul McGowan doesn’t know if Eminent Technology is still making planar loudspeakers, just how low IS the visibility of the company?!

To set the record straight: though Paul differentiates between a "planar" and an "electrostatic", while not all planars are electrostatics, all electrostatics are planars. I routinely see Magnepans referred to as planars (by Steve Guttenberg, for instance), which they of course are. But so are electrostatics. When Paul and Steve say planar, they are speaking of planar-magnetic loudspeakers. Both Magnepan and Eminent Technology make them.


The Eminent Technolgy LFT-8 planar-magnetic loudspeaker was introduced in 1989/90, and remains in production today. It has gone though a few revisions over the past thirty-three years: in 2007 an improved woofer replaced the original, with a change to it’s nomenclature: the LFT-8a. In 2015 an improved tweeter replaced the original, the new model designation being LFT-8b.

The LFT-8b remains available, and there is also a new version of the LFT-8: the 8c. The 8c consists of the same planar-magnetic panel as the 8b (which contains the midrange---180Hz up to 10kHz---and tweeter---10kHz and above---drivers), but with the monopole woofer of the 8b (for frequencies 180Hz and below) replace with a "gradient" dipole woofer (still a sealed enclosure, but with a 6.5" rear woofer added to the 8" in the front), which simply bolts on in place of the monopole woofer enclosure. Also included with the 8c is a power amp for the woofers, and DSP for the low-pass x/o filters for the woofers, time-alignment of the panels with the woofers, and equalization.

The LFT-8b retails for $3200, the 8c $4500, shipping in the U.S.A. included.


Magnepans are commonly discussed and owned (I own a pair), but the Eminent Technology LFT-8 remains virtually unknown (I also own a pair of the LFT-8b). Why is that? It has received rave reviews (REG in TAS, cudos from VPI’s Harry Weisfeld---who characterized the midrange of the LFT-8b as "the best I have ever heard", a number of reviews in the UK hi-fi mags), yet remains virtually unknown to the vast majority of audiophiles. I know ET has few dealers and does no advertising, but still.....


Of course, I had to read up on the TRW-17. Needs to be installed in the attic or a location where the wall acts as a baffle. Figure $30k. 1-20Hz. Uses coil driven blade angling tech, not unlike a helicopter. Used at carnivals and special events. More of an infrasonic device than a sub in the conventional sense.

Do a quick search on the forums here but ET was at the recent Florida Audio show showing a new model that got a LOT of great press. 

ET also makes a great tonearm as well, I know a few people who have or have had them.  Very interesting company, clearly under the radar.

DougShcroeder do have a good understanding on ET. I believe he own their speakers. I might be wrong.

bdp, I tend to agree, even though I've never owned ET  speakers.  I have owned a few pairs of Maggies and I agree the ET design makes more sense to me.  Better design to avoid a crossover through so much of the range and also more durable.

Regarding Paul's comments, he seems like a nice guy and obviously an enthusiast (as a manufacturer), but I've seen several bits of over-simplification or plain misinformation in his comments.

To your main point, I never understood why ET doesn't have more market presence either?

.....all electrostatics are planars

I'm not sure I would call the Martin-Logan curved electrostatic panels a planar loudspeaker. I would call it a panel loudspeaker, though. A plane is flat...


@pryso: Excellent point about the LFT’s avoidance of a crossover through much of the audible range. For those who missed it, the midrange planar-magnetic driver in the LFT-8 reproduces from 180Hz up to 10kHz, with NO crossover! That is a very big deal. Fans of single-driver designs take note!

Bruce Thigpen was very impressed with Jim Winey’s original Magnepan design (the Tympani), but thought he could do better. So he designed his LFT driver as a push-pull transducer, in contrast to the single-ended of the Tympani. A push-pull driver produces less distortion than a single-ended one, of course (the wires attached to the Mylar film of the drivers better remain in the field strength of the driver’s magnets). Winey eventually designed and built an excellent push-pull ribbon tweeter, but the midrange drivers of his MG.7, 1.7, and 3.7 remain single-ended. Also, the LFT driver is built into a substantial metal frame, as opposed to the Mylar of the Maggies being merely glued and stapled onto the speaker’s MDF frame.

The crossovers for all the LFT-8b drivers (the p-m midrange and tweeter, and the 8" dynamic woofer in a sealed enclosure) are simple 1st order/6dB-octave filters, with few parts. And the LFT-8, while very low in sensitivity, is an 8 ohm load. The m-t panel itself is an 11 ohm load, so great for tube amps. The LFT-8 comes with two sets of binding posts, for easy bi-wiring or (even better) bi-amping.


The ET TRW-17 Rotary Woofer has been described (by Peter Moncrieff in International Audio Review, I believe) as the world’s only true subwoofer. That is because it is designed and intended to reproduce "only" 20Hz and below. Most loudspeakers have a hard time reproducing even 40Hz at lifelike SPL with low distortion, and even the best subwoofers can’t do 20Hz very well (except perhaps the Rythmik’s).

The current Stereophile contains a review of the Klipsch La Scala AL5, and both the reviewer (Alex Harbestad, a name new to me) and John Atkinson’s measurements revealed the output of the AL5 to plunge rapidly at 50Hz. And that from a 15" woofer! Totally unacceptable, to me at least. The lowest note produced by a standard 4-string bass (electric and acoustic)---the E string played "open"---is located at approximately 41Hz. If a loudspeaker can’t reproduce 41Hz, I ain’t interested ;-) .


We all know that hi-fi’s are still---after 100 years or so of development---quite incapable of reproducing music that comes close to that which we experience when heard live. I have long believed a large part of that failing has to do with hi-fi’s failing to reproduce (and perhaps recordings failing to capture) the physical properties of live music. Live music is sensed not only by our ears, but by the rest of our bodies as well. While our hearing may not perceive frequencies below 20Hz or so, our bodies certainly do.

I would love to hear the TRW-17, and have seen pics of it in the system of one audiophile (he installed it in the floor of his listening room). He pairs it with his loudspeakers, which are a pair of Martin-Logan ESL’s augmented with the bass panels of the Magneplanar Tympani loudspeakers. Yeah, baby! I LOVE the sound of the Tympani bass panels (I own a pair of them as well, the T-IVa), but they are good down to only 30Hz at best (when braced and fed a LOT of power).

I have 2 sets of lft 8b they are great for me .Bruce answered all my questions.was super professional and knowledgeable.  Speakers arrived as advertised. I have them bi amped.thx

Interesting subject. Can think of a few things that might have slowed ET down.

1. In their beginning years Magnepan partnered with Audio Research a lot. Not a bad company to be associated with.

2. ET went hybrid with planar/cone woofer. People might prefer running Maggie’s with sub.

3. IMHO ET acquired a very tweeky reputation. The air tonearm was rough to keep working. Friend was always fiddling with it. Noisey Air pump had to be located in another room. I remember a home-made air filter, built into a milk jug, to reduce air turbulence. The system also had to be routinely purged of condensation and cleaned. The only arm I remember being as big of a pain was the Souther linear tracker. The rotary woofer is also way out. Bruce is very smart, but might need to pay more attention to convenience.

Often see the argument about ET speakers having less distortion than Magnepan. ET has magnets in front of the driver, causing diffraction. So which distortion is worse? Does the ET woofer have less distortion than a Magneplanar bass panel? Might depend on frequency range and volume. Would like to hear the ET speakers.




Nice article, thanks. Answered my question.

I’ve always been interested in the ET speakers, barely missed a preowned pair once.

@wsrrsw , as soon as I followed your link, I *L'd*....

Upon reading our OPs' opening statement and his desire for 41hz, the LFT 8s' seem like the rational choice, But ...

There's always the '$ No Object' crowd....*G*  And I wish them well, and hope you've got the space for the Trw-17, and the more power to you.

You'll need it...;)

I remember reading that same article back in '10; the 'pitch-shifting blades' instantly reminded me of 'prop wash' from light aircraft, hearing the 'pitch shift' as the prop is adjusted....having grown up the son of one who worked for Douglas Aircraft in SoCA....

Novel use of the tech; not for the average HT, no....😏

....though it does start to edge into 'He Who Need Not Be Named' sort of turf, what with concrete walls for drivers and an astounding level of confidence in the quality of his hearing and its' perfection beyond us mere mortals...

...and at the cost of the rotary... What if you didn't like it? *cringe*L*

WTH would it cost Now, given the improvements in 'circuit magic', acoustic materials and the app of active room eq, etc., ad near-infinitum....?

Reality...what a concept...*sheesh*L*




Thanks @wsrrsw: Thanks, I hadn’t seen that write-up on the TRW-17.


@uncledemp: Though "normal" recordings made in studios are limited in very low frequency content, some recordings made in very large "rooms"---cathedrals and churches, large theaters---contain very low (below 20Hz) information. That’s why you can hear the sound of the room itself (the dimensions of large spaces allow very low frequencies to propagate.). I have some EMI and Decca Classical LP’s in which the environment in which the recording was made is quite audible/evident---a HUGE space. I can only imagine what the ET TRW-17 would make them sound like!


@aldnorab: Some good questions. Here’s some answers to them:


1- Very true. That’s how I learned of the Magneplanar Tympani T-I’s (Gordon Holt’’s review of them---which was not entirely positive---had not yet appeared in Stereophile). In the Spring of 1972 I happened to visit a newly-opened hi-fi shop on the very day Bill Johnson was delivering and installing a complete ARC/Magneplanar system in the shop’s excellent sound room (Bill was a pilot and owned a plane, so flew himself and a demo system to new dealers who were located far from Minnesota). I made like a fly on the wall---keeping my mouth shut and my ears open, listening to Bill and Walter discuss all thing hi-fi. I got quite an education that day!

I had already heard the Infinity Servo-Static and Dayton Wright electrostatic loudspeakers, but was unprepared for the sound the ARC/Maggie system produced. Shortly thereafter I bought from that dealer (Audio Arts in Livermore, California, owned and operated by Walter Davies, as fine a man as I have ever known. He later created the Last Laboratories line of excellent LP and tape preservation products.) the same system: Tympani’s bi-amped with the ARC passive crossover and D-51 and D-75 power amps, an ARC SP-3 amplifying the signal from a Decca Blue cartridge mounted on a Thorens/Decca player. That was Johnson’s reference system, except he had brought along a prototype tonearm in development at ARC, which was never put into production. I remember it resembling the Weathers and Grado arms of the 1950’s and 60’s.

2- Prior to introducing the LFT-8, Eminent Technology had already marketed LFT models which were not hybrids: the LFT-3, LFT-4 (a pair of which I also own), and the LFT-6. Instead of a dynamic cone woofer, those three models had planar-magnetic woofer diaphragms, which were of course somewhat large (bass frequencies require drivers which have either large radiating surfaces---planars of course do---or considerable excursion capabilities---planars don’t---in order to be able to "move" enough air.

To make an LFT model of more modest proportions, Thigpen decided to use a dynamic woofer for the LFT-8. He readily admits the 8" woofer is the LFT-8’s weakness, but for those with a room big enough one could use the bass panels of the Tympani’s with the LFT-8 midrange/tweeter panels. Or, since the LFT-8 woofer operates up to only 180Hz, in place of it one could instead use a pair of the fantastic Rythmik Audio/GR Research OB/Dipole Subs (which---unlike "normal" subs---can be used up to 300Hz.). Or, get the new LFT-8c, which incorporates a new sealed dipole woofer. By the way, Magnepan has itself been working on their own dipole woofer for some time now, and it will eventually come on the market.

3- All drivers are made with compromises. Do the front-mounted magnets of the LFT driver cause diffraction? Remember, the more expensive Magnepans---the 20.7 and 30.7---themselves employ push-pull midrange drivers, with magnets front and rear. Which is worse: a small amount of diffraction, or a large amount of harmonic distortion? Only you can decide. ;-)

If you wish upon a star...

SOAF= Zero....unless vision-impaired..

Even then, with the 'hearing compensation' that's typically existing...

O, Lucky Man....;)

@avsjerry: That pic is with the front grill frame & cloth removed. With it in place, the LFT-8 looks no worse than do Maggies. Not pretty, but not horrible.

Would love to hear with my Acoustat Model X’s.  Over the years, I’ve tried probably ten subwoofers with them and have never found one yet that’s fast enough.

@bdp24, seems like we share a few perceptions.

For years I've set a goal for 40 Hz bass in speakers I've owned.  Not necessarily flat down to that frequency, but at least reasonable output.  I'm a big jazz fan and the 42 Hz (as I've typically read) of the open E string on a bass defines the minimum of what I expect to hear.

Basic need for lower bass.  Not that many instruments extend below 40 Hz, nor is there an abundance of music scored in that range.  But I too learned that the sense of space in large recording venues is better captured by systems which extend into the lowest octave.  So that elusive sense of realism of live experience is better supported by deep bass capabilities, even when not attempting 16 Hz organ notes.

I don't remember the year, but clearly recall the experience of Bill Johnson coming to a San Diego dealer to set up an ARC tube system with a pair of Tymphany speakers.  Still, one of the better audition experiences I've had after decades in this hobby.

Unfortunately, at my age I'm looking to simplify my system.  So while the larger rec room where I had hoped to set up a good second system (where ET 8Bs would have been contenders) was a dream, I must admit it is not likely to happen now.

@curiousjim: Allow me to suggest a subwoofer that is ideal for your Acoustats: The Rythmik Audio/GR Research OB/Dipole Subwoofer.

Planar lovers (especially electrostatics) have been looking for a sub which can "keep up" with their loudspeakers since QUAD and KLH introduced their ESL’s in the 1950’s. Everything form the 24" Hartley woofer in a huge enclosure to a transmissionline-loaded KEF B139 woofer (David Wilson used two B139’s in each of his original 1970’s WAMM model, for midbass frequencies.). The Finnish company Gradient was for a time making OB/Dipole subs for use with both the QUAD ESL and QUAD 63. The design was good, it’s execution not-so-hot. It was reviewed by Robert E. Greene in TAS, if I remember correctly.

Traditional engineers will tell you (the guys at SVS did me) that a woofer can’t be "slow", as it is reproducing only "slow" frequencies. That is of course an over-simplification of a more complex situation. In his excellent series of Tech Talk videos on YouTuve, Danny Ritchie of GR Research discusses all things loudspeakers, including subs. I won’t bore everyone with information better explained by Danny, but suffice it to say that the reason subs have never sounded "fast enough" to blend seamlessly with ESL’s can be explained. Which Danny does.

One important factor is that monopole subs (whether sealed or ported) don’t propagate sound in the same manner as do dipole loudspeakers, nor "load" the room the same way. Employing either dipole planar woofers (as Magnepan does) or traditional woofers used in dipole fashion (a woofer mounted both front and rear in an enclosure, in polarity opposite each other, just as the front and rear of a dipole loudspeaker) solves that problem.

Magnepan has been working on a dipole sub (but it is not open baffle) for a few years now, and has demoed it at a few high end dealers (and hi-fi shows, I believe) around the U.S. The woofer system is the basis for an upcoming Magnepan model: The 30.7 For Condos. It will have Magnepan planar-magnetic drivers for midrange and treble, the woofers of course for bass. Magenpan will also offer the dipole sub as a separate product, for use with their other models (or the loudspeakers of other companies). Eminent Technology already offers a similar woofer system, but it is available only in their LFT-8c loudspeaker. Perhaps ET will sell the woofer system separately? It is offered as an upgrade for current LFT-8b owners, $1500/pr, I believe. Complete with power amp and DSP for crossover functions, time alignment, and equalization.

But the best answer is the amazing OB/Dipole Sub from Rythmik Audio/GR Research. Either two or three (your choice) 12" servo-feedback "free-air" woofers mounted in an open baffle frame, low frequencies (up to 300Hz) propagated both front and rear, just like dipole loudspeakers. The best thing I’ve found for use with my QUAD ESL’s, Eminent Technology LFT’s (both -4 and -8b), and Magneplanar Tympani T-IVa midrange/tweeter panels (I have no room large enough for the Tympani’s bass panels. They are HUGE!).

The sub is available only as a kit (which contains the plate amp---which provides the best controls in the business---and the woofers.). The OB/dipole frames are your responsibility, but GR Research has a company in Canada which makes the required OB frame, shipped as a flat pack. I know that sounds like a lot of work, but the frame is very well designed and fabricated (on a CNC machine, the MDF very high quality and thick), and easily assembled (only wood glue and clamps needed). Reasonably priced, too.

The genius speaker/crossover designer Siegfried Linkwitz came to the conclusion that open baffle/dipole loudspeakers are the way to go, and designed and sold (he died back in 2018, but arranged to have a colleague continue to market his designs) a loudspeaker that includes a sub of the same design as that of GR Research. But the latter is the superior sub, imo.

End of sales pitch/shill. ;-)


Thanks for the tip. When I get a chance, I’ll give Danny a ring. Years ago, I built my second to last sub with two Dayton 8” drivers. I got very close,  but I could never get all the way. 

I have read many posts in which @bdp24 praises the ET LFT8b's and having owned (and still own but rarely use) Magnepans, I finally decided to look up an ET dealer close to where I live.  I called to ask if I could visit and listen to a pair but was disappointed to find out that he no longer carries the speaker since there was never much interest in it and he sold very few.  I really would like to hear these speakers and have identified other dealers within a few hours drive.

Any of the powered bass biamplified Vandersteen models are flat in most rooms to the twenties, my 7’s with the patented Ti / aluminum push pull sub are -1 db at 20 in a decent sized room ( see Poverty Bay sound in my system photos ). My Treo w single Sub 3 are flat  into the high twenties…. and without using ANY of the available 11 bands of ANALOG eq….

EJ - you are welcome to visit any time… and as you have previously invited me, i really should get down to hear your Tympani - you know i am a fan….

Also, Bruce is his own genius… i dont think we can know his goals for ET ? Thankfully we have the speakers…. yes of course, i have heard them…they are very sweet, somebody looking for a planer, curved panel nit included would do WELL to audition them….

Best to all on our shared quest for better more emotional music reproduction 


And i agree w genius and frustration w ET-2. I sold more than a few maddening Souther back in day and agree there as well. Thankfully we do have at disposal here on the forum an excellent thread on the ET-2 arm optimization / maintenance by many contributors…..



During the development of our OB line arrays we researched and tried several types of woofers configurations and ultimately designed our own dipole woofer system. We came to the conclusion that dipole woofers complement OB speakers best, at least in our case. Our dipole woofers have been successfully used with several dipole panel speaker system. I call them woofers and not sub-woofers because they cover from 20Hz to 120Hz in our system and work very well up to 200Hz. 


Sorry, hit the "post" button...

I suggest looking into dipole woofers to best compliment OB speakers, not necessarily ours because there are lower priced systems out there.

Not a problem @arion, at least for me. Yep, for dipole loudspeakers (of which most OB loudspeakers are) dipole woofers ARE are the way to go. And I complete agree with your calling drivers which reproduce "only" down to 20Hz woofers, not subwoofers. Separate enclosure with driver(s) became known as subwoofers because most "full" range loudspeakers are of course nothing of the sort. Since those speakers have woofers, what should the industry call a product which reproduces very-low frequencies, those below what the speaker's own woofers can't reproduce? Why subwoofers, of course!

@tomic601: Hey there Jim! Yep, I heard the Vandersteen subs many times over the years at Brooks Berdan Ltd., one of Richard's first and best dealers (he sold a LOT of Model's 2 and 3). When Brooks decided to not sell Richard's new higher-priced models (beginning with the Model 5, I believe) I knew he was making a big mistake. That was not acceptable to Richard, and Brooks was no longer a Vandersteen dealer. Brooks, you fool! ;-).

Brooks wanted to sell his customers (and potential customers) who were looking for higher-priced loudspeakers Wilsons, not Vandersteens. Why not offer your customers the choice of both? The more product you sell of one company, the better wholesale price you get, hence more profit. I sat in on a meeting Brooks took with Wilson's head of sales at CES, and witnessed how dealers are pressured to sell more product. It wasn't pretty.

I have a pair of the LFT-8bs. When I look at them I see terrible build quality. Stuff is poorly welded together. The frame isn’t sturdy (you can move it with your hands). The legs are screwed directly into the woofer box without pilot holes or any housing for the screw to go into. The ribbons look like they’re wrinkly all over (my Apogees, also known for poor build quality back in the day, are a thousand times more solidly built). I also eventually stuffed a piece of Kleenex behind one section of ribbon because I heard it rattling back there. It worked!

But holy hell do these ETs sound great. I kid you not when I say they rival the best sounding speakers out there at audio shows. I don’t get it, but Thigpen is a master magician.

I plan to build a new walnut outer trim for them since the ones that came with the speaker are poorly put together.

I wouldn’t trade these for a pair of Wilson’s right now. Mainly because I know I’d lose something with the sound.

I do have them paired with an old 400 watts/ch Krell amp. Thigpen recommends no more than 200 watts per channel and I tried that but this 400 watt Krell allows these speakers to absolutely sing.

The ribbons are magic. The bass is tighter than anything decent I’ve heard at audio shows. Yet the woofers and the box they come in look like they were made from old pizza boxes. Okay, maybe exaggerating a bit on the poor build quality.

I was at one point considering buying 3-way YG Acoustics speakers, but these sound so absolutely perfect that I don’t want to jinx it.

I don’t even have them spiked into the carpet- at this point I’m afraid to touch them or experiment with them in some other position or even upgrade them to the new woofers because I can’t risk losing this beautiful experience.




I think electrostats never caught on for a couple of reasons:

They had a tendency to arc if over-driven.  I believe this has been largely solved. 

They also have to be plugged in.  Neither of these are problems with Magneplanars. Although there are SQ differences between the 2 designs, there's enough similarities that Maggies won the marketplace and electrostats got an even smaller wedge of the market.  Quads remain the most famous of the electrostats, but my guess is that Martin Logan has the most units sold.


FWIW, the low note on a concert grand piano is ~28 hz, with extended range pianos going down to 16, and at least 1 pipe organ to 8 hz!


1- To get rid of the wrinkles you adjust the LFT driver tensioning mechanism.

2- I take it you don’t have the speakers mounted on the stands made by Sound Anchors specifically for the LFT-8b? Get a pair, they’re pretty cheap!

3- Grant Mye has made his stands for the LFT-8. It includes support arms which extend from their base all the way to the top of the LFT panels. That provides increased structural stiffness and improved sound quality. By the way, the MDF frames of Maggies are even less stiff than the LFT panel of the ET’s. That’s a penalty you pay with a planar loudspeaker.

@bdp24 thanks! I’ve read that in the user manual but I’ve just been afraid to mess with it. Really I need some time to adjust and listen, rinse and repeat. But they sound so wonderful even in their flawed state!


I do have the sound anchor stands- these are the large heavy thick metal legs that Thigpen recommends for his speakers, correct? I have them but they were a pain to screw into the woofer box- felt like I was probably causing some sort of new resonance due to the screws sticking out inside the box. My biggest worry though is that I’ll lose a nail and fracture my little toe on them. One of the speakers sits right in the path of my listening room door and I’ve accidentally caught my pinkie toe on it multiple times. The pain is awful. I’ve been on the search for some sort of rubbery material I can place over them to prevent losing a toe someday.

On the subjection of tensioning the ribbons on the panels- do you have any literature on how to go about it the right way? I don’t want to just be loosening/tightening hex screws without knowing what I need to be adjusting first.


Thanks for the tips! I can’t imagine these speakers sounding any better but there it is… something for me to chew on.

Yep, there it is. By the way, the recommendation of an aluminum wrench is a REAL good one. The magnets in the LFT drivers exert a pretty strong pull on ferrous materials (steel)!

@bdp24, yes...nothing like having a tool yanked from your hand. 😬

Brass wrenches are better, but mind the alloy and test cheap. *l*

Agreed, a nude Maggie isn't cute by no means and I'll give the 8's a nod for at least looking 'business-like' about being sans grilles... ;)
Some of us don't mind facing nudes..😏

I have my Heils...I know a good ribbon or planar when I stumble into them.
I'd give the 8s' my time. *S*

We have a pair of LFT-8b speakers, and the sound is wonderful. Very detailed, great separation and frequency integration, though we do use them with subwoofers for extended bass.

I have to agree that the finish is not as high as many expensive speakers. I think Bruce found a way to manufacture excellent sounding speakers at a truly low price compared to others, and the tradeoff is that while these are hand-made in the US, he uses pretty common materials - steel plate, steel channels, neodymium magnets, and mylar with printed aluminum. Yes, I agree the woofer boxes could be supplied with threaded inserts, and the wood trim could be more impressive.

However, the sound is quite amazing, and very satisfying. We can listen all day with no fatigue, and the speakers handle a wide range of music and volumes. These replaced MTM/subwoofer box speakers with Seas Excel drivers that sounded great.

We also have an ET-2 tonearm on our Oracle turntable, and while it is fussy to set up, and I wouldn’t recommend it to someone who isn’t technically competent so they can do their own adjustments from time to time if needed, we have overcome most of the challenges with the tonearm, including installing the air pump in a sound-isolated cabinet a few feet away from the turntable. It also has the damping trough which really enhances the sound and performance.

One challenge with the speakers is the midrange panels have to be adjusted properly, and the mylar can stretch over time. We had one speaker that gave me a lot of trouble with adjustment, but Bruce sent me a couple of additional hex adjusters, and finally, when the panel wouldn’t stay in adjustment (buzz at very specific mid-low frequencies at loud volume), Bruce sent me an entire replacement steel frame/panel with mid-range panel installed and adjusted, all under warranty. A week later, Bruce sent me replacement tweeter ribbons and fuses/fuse blocks (at no cost) because I had stupidly blown the tweeters by incorrectly connecting a new active crossover. Fortunately I have the tools and expertise to replace the ribbons myself rather than sending them in for replacement - and what I'll be doing later this morning.

What I’ve come to accept is that Eminent Technology makes true audiophile gear, but it can sometimes require maintenance skills that not all audiophiles have acquired. However,, Bruce goes out of his way to ensure that any problems are resolved. I’ll be ordering the new woofer/DSP upgrades tomorrow!


EJ - I know from very personal and direct experience RV puts zero pressure on dealers.i think if we examined the long running tenure of the core dealers we might find the mean at 2 decades…..

For the definition adherence, the Vandersteen sub 9 is available…

There is a place in the audiophile world for panels and a serious appreciation of what they do well. Those looking at my various system pages will come across Quad, Apogee and Magnaplaner. 

Sound anchors help improve the sonics of a great many speakers…. Mye as well.

Best to all


Yes - we also have the Sound Anchor toe stubbers. I do think they improved the sound of the LFT 8bs.


@tomic601: Yeah Jim, Richard Vandersteen is not your typical high end audio designer and manufacturer. If I wasn’t a committed planar enthusiasts it would be Vandersteen’s I would probably own. I have listened to music through them for many hours at Brooks’ shop.

I had the pleasure of joining Brooks for dinner with Richard at the steak house in the venue Richard was showing at during one CES in the late-90’s, and found him to be very down-to-earth, a regular working-class kinda guy. No "snooty" pretenses at all, of which I saw a lot at various CES’ I attended.

Richard ordered the wine, he obviously knowing his stuff. I’m more of a whiskey drinker, and Brooks? Milk. I swear to God! ;-) Richard picked up the tab (Brooks and I had our women in tow, and there were a few others in our party), a good thing as it was the highest I’ve ever seen!

@bdp24 thanks for the aluminum hex wrench suggestions.  I hadn’t thought about the magnets but you’re right.


@gktaudio you’re absolutely right.  Something my friend and I have pondered is whether Bruce would be willing to make a premium build version of the LFT-8bs if offered enough money.  They are an absolute steal at the $2500 price point.  Although I think he may have raised prices a bit recently.

@sandpat: Yup, they’ve gone up to $3200/pr, plus a coupla hundred for a pair of the Sound Anchor base/stand. But that does include shipping within the Continental U.S.A., making them imo a better value than the $3000/pr Magnepan MG1.7i (I auditioned them both).

I’ve tried to install subs in a Mazda RX7 (rotary engine). It’s darn near impossible!

I have been listening to the 8b's since 2020. This past November I upgraded to 8c's. This is a drop in replacement of the woofer unit in the 8b. Whereas the 8b has an 8" woofer, the 8c uses a front firing 8" woofer and a back firing 6" to form a dipole configuration. Additionally, the woofer has a built-in 250W plate amp as well as  DSP to adjust for bass level, high pass time delay, and adjustments for room modes ( provided that you use an appropriate computer software and measuring devises ).  

The 8c is a legitimate full range speaker. With the patience to tweak and fine tune the DSP adjustments, it throws a holographic soundstage, improving on its mid-range magic, and provides satisfying bass response. I believe I have yet to exhaust the fine tuning of the 8c and it is already becoming a completely transformed speaker from the 8b's. 

As someone mentioned, Bruce showed a brand new speaker prototype in the recent Florida show. It uses the same LFT panels except with neodymium magnets and 6 front firing 8" woofers plus 2 back firing 6"  woofers on a separate woofer tower. Efficiency goes up to 91db. 

Yes, I too hope that Bruce and ET gets more recognition.