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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.....

128x128bdp24

Showing 2 responses by pryso

pryso
1,901 posts
 

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?

pryso
1,901 posts
 

@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.

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