The criteria for loudspeaker choices.

The Eminent Technology LFT-8 is an over-looked gem of a speaker! With its push-pull magnet structure it has superior transient response in the vital midrange compared to Magneplanars. Plus the 8-inch driver extends the bass nicely. Well done Bruce Thigpen!

@deep_333

bdp24 already addressed this question on 12/23 in one of the posts you cite.

The now-deleted post was from @vonhelmholtz, asking "Are you a dealer, or a representative of ET?" No offense taken, that’s a fair question.

The answer is nope, just a very satisfied ET LFT-8b owner, doing what I can to help reward the outstanding work of ET designer Bruce Thigpen, and direct magnetic-planar loudspeaker fans to what I consider the best value in that type design.

I am living in the southern most town in Washington State (Vancouver), just over the border/river from Portland, Oregon. If I were working for Eminent Technology I think I would be living in Florida. And being paid to do so.

I’m not a dealer, or a manufacture’s rep, or hold any other position in the hi-fi industry. What do I have to do, show my income tax return?!

Anyone wanting proof I bought the LFT-8b’s as a consumer, give Sheila Berdan at Brooks Berdan, Ltd. in Monrovia, California a call and ask her (I'll provide my name). Sheesh!

@deep_333

If you had been around here longer than 4 years you wouldn’t have made such an asinine accusation. You’d know that @bdp24 is a well respected contributor who always has something interesting to say. Unlike yourself.

On another note, I guess tags don’t work in this forum anymore.

@ozzy62 Wrote:

@deep_333

If you had been around here longer than 4 years you wouldn’t have made such an asinine accusation. You’d know that @bdp24 is a well respected contributor who always has something interesting to say. Unlike yourself.

I agree!

Mike

 @bdp24 is a well respected contributor who always has something interesting to say.

+1.  

 @bdp24 , what do the specs say about the  power suggested to drive those speakers?  (Unless I missed that even though I did a couple of re-reads.  If so, I apologize--I am half blind, and the half that works gets worse daily.))

. . . never mind, I just did some speed reading (TAS), and they quote a suggested 50 to 150 wpc and they say that nominal impedance is 6 ohms (5.6 ohms minimum)..

As soon as I can get some weekday time, I really want to go to PS Audio and audition the 20’s and 30’s.    Have been a fan of ribbon drivers since I replaced the tweeters on my DQ-10’s and I have been thinking of replacing my KEF’s for a while now.  I know they do trade ins on electronics.  I wonder if they will do it with speakers now that they sell them?

Website says the speakers are eligible for trade-ins up to $875.

Note that the Magnepan DWM woofer is also a push-pull design and it is flat right into the treble. It is an absolute wonder with my Quads - especially with a decent mounting platform - the one supplied is more stylish than functional.

From what little I know about speaker specifications, and this is what I have learned here, 83.5 is a very low sensitivity and on paper would suggest a hard load to drive(?) but on the other hand an impedance that only dips to 5.6 ohms is extremely good, and since they are suggesting 50 to 150 wpc, the stable impedance must be what makes up for the low efficiency?

The LFT-8b makes bi-amping a simple proposition, and allows a tube amp to be used on the Planar Magnetic drivers/panels (tubes love an 11 ohm load), and a solid state amp on the sealed dynamic woofer. Splitting the signal at 180Hz eliminates the need for a high current ss power amp. In contrast, the MG1.7i---having a single pair of speaker cable connectors, as well as wiring the various P-M drivers in series, not parallel---needs internal surgery to be bi-amped. The combination of a 4 ohm (and lower) load with an 83.5 dB sensitivity makes a high current amp mandatory with the 1.7i, which is not the case with the LFT-8b.

But back to the PS Audio FR5. I have no doubt it is a fine sounding loudspeaker, maybe even great. And a good choice for a small room. The point I want to draw to everyone’s attention is that if the case PSA makes for the Planar Magnetic driver is as strong as they obviously believe, the LFT-8b uses that technology all the way down to 180Hz, the FR5 only down to 1750Hz. That’s a drastic difference. A whole lot of the sound of music is found in the 180Hz to 1750Hz range.

But then the FR5 is a "box" speaker, the LFT-8 a dipole planar. Not everyone likes, wants, or can accommodate the latter. For those people the FR5 may be a welcome offering. I find a mini-monitor, especially one with a price tag of $3499 plus shipping---of little interest.

For their price decent but components are of lower quality .

for example low grade brass connectors to start  vs a copper WBT 

3 x less conductivity then Copper = more resistance noise to start,

the the critical Xover ,Very  low quality parts .I have worked with many people in over 20 years upgrading Xovers even in much more expensive loudspeakers .

these speakers ,maggi worst connectors Ever and frames I owned 3 flex like a sail,

ps audio ,and Emminant tech. Drivers all made in China . 
which I am no far .as a ex Audio dealer speakers including packaging 4-1 ratio 

is the norm a $4k speakers $1k into the build ,you get what you pay for , better buying something. Much better used  ,the Xover is for sure a good place to start 

if you did buy them  and wanted a very good upgrade. For maybe. $1k in parts 

look inside you will see most likely all yellow no name China capacitors ,and resistors , on many $10 k speakers Solen which are like a 7 out of15 on the quality scale , go to Humble homemade hifi capacitor test

You cannot assume that a technology good for one purpose (e.g., tweeter) will be best doing the job at other frequencies.  If that were the case, there would be only one driver or type of driver in all speakers.  There probably are tradeoffs made in extending the planar magnetic driver down to frequencies as low as the ET speakers go, such as, dipole cancellation of the front and back wave that increases progressively as one goes lower in frequency.  i don't think one can compare technology and design specifications to determine which is the superior approach.

That said, I've heard, and like, ET speakers.  For the money they are very good bargains.  I am glad you pointed them out because they are often forgotten because they are not heavily promoted by the manufacturer. 

I appreciate the OP calling out the inconsistency of PSA's marketing hype. I've had a very bad experience with PSA gear and after looking deeper into their company and their marketing approach I have found a lot of evidence that their products are poorly engineered. Paul is very good at telling a story but the story fails upon close scrutiny. Personally, I don't trust anything that PSA says.

8th-note, what are you referring to here?  Can you be somewhat specific?  What is poorly engineered, in your view?  

My lft 8b r great but can't get the spl of the fr 30 I put 1k watts through and handled well on the dB 96 I have the bg and genesis with the 72 inch ribbon goes from 180 to 20k again can't get high spl luv them all

My lft 8b r great but can't get the spl of the fr 30 I put 1k watts through and handled well on the dB 96 I have the bg and genesis with the 72 inch ribbon goes from 180 to 20k again can't get high spl luv them all
 

Will someone please translate this into English?

Well we're talking about speakers that go from 180 hz to 20k all by them self and ribbons that bohlender graebener genesis and lft 8.they all sound good but the drawback well known is you can't get super high spl sound pressure level a standard measure of loudness out of them .sorry I mostly deal in Latin with a 15 blade scapel and I'm not and English teacher but do teach alot of students.enjoy the music

Hope you enjoy your michi m8 cuz they sound great pushing the fr 30.

If you cross over a planar with a steep enough crossover you can hit 110db plus. They use planar magnetics in arenas......They can play as loud as you need. But, you have to limit their excursion. My two way fully open baffle speaker uses 2 12 inch woofs with nothing but a coil on them, so a 6db per octave crossover at 300hz. Above it on a shelf is a small 8 inch dipole $50 planar driver that is running wide open (no crossover). It will only play 95 db in my small room before it starts to distort. If I put a cap before it, I am sure it could reach 100db......and if I did a 12 db per octave xover I could hit 105db.....etc. etc. If you run 4 of these small planars in series parallel you would have a 96db plus, 32 inch line array and it could handle way more power. If you use the big 10 inch planars from Parts Express or Radian (these things will handle a ton of power) and you run 4 of them in series parallel you could get way, way over 100db with no lower end crossover.

I will have info on my website about my speakers within a couple of weeks.....it will have pics and how to make them, etc. Less than $1500 gets you a seriously great speaker.....stay tuned.

I am sure the new PS Audio speaker is nice......HOWEVER, it uses a ton of not great xover parts.....crosses over the planar way above the midrange....and is 83.5db sensitive and will require a serious amp to play loud. My speaker is 93db sensitive, it uses a zero crossover planar all the way down to 400hz....and is fully dipole and costs you way less and will do bass into the low 30s.....However, it won’t have resale value and you have to make it yourself (very easy). I am not making my speaker to sell.....just letting you know what can be done.

Or as an alternative designed to be driven with a 2 Watt OTL amplifier

https://www.transcendentsound.com/16-ohm-speaker.html

Yes, I use the same tweeter......but using them side by side is not a great idea.  He uses ordinary parts and execution (not a tweak....whatsoever).  He designed that for a low wattage OTL amp.  I am sure it sounds good....like lots of things.....but not a serious design or execution.

The OP’s post seems strange- if you like speaker A, then try speaker B?

I have owned only one PS Audio piece (the old 200C power amp), which I consider to be well designed and built. So did J. Gordon Holt and Tony Cordesman, reviewed in Stereophile.

As for Eminent Technology (not "Emminant tech"), Bruce Thigpen manufactures his LFT drivers himself in Florida.

@kennyc: The reason I was linking and comparing the PS Audio FR5 and the ET LFT-8 was because the case PS Audio made for the superiority of a planar magnetic driver over a dynamic was quite adamant on their part. If they feel so strongly about planar magnetics (I like them too), why not make a speaker fully fitted with p-m drivers? Using a p-m driver for a tweeter is well and good, but the PS Audio FR5 reproduces the majority of the music with a 6.5" dynamic driver. The ET LFT-8 does it with a single large p-m driver. 180Hz to 10kHz!

You ET people are unrelenting. 

Always trying to convince people that they're better than the acknowledged masters of the category. We chuckle.

Such as? I also own Quads ("57"s), Maggies (Tympani T-IVa), and ESS (Transtatics). In the past I have also owned Infinities (RS-Ib), Fulton Industries (Model J), a few others.

It’s not that the ET LFT-8b is "better than the acknowledged masters of the category", but rather that at $3200/pr shipped they are a great bargain in a dipole planar design. Why are some people bothered by others feeling that way? Weird.

Steve Guttenberg’s review of the LFT-8b (and 8c) are as enthusiastic as any review of his I’ve seen. Robert E. Greene’s in TAS and a couple in the British press (readable on the ET website) were equally enthusiastic. I’m in good company.

As a dipole planar-lover, I feel almost obligated to let others like me know about the LFT-8, especially those contemplating the purchase of the MG1.7i. I compared the two, and though they are in some respects similar in design, they sound very different from one another. Is informing others of another speaker to audition before purchasing the MG1.7i now considered "shilling" for ET?

Please look at the history of secretguy......you will see that he is mostly complaining. Is this a light heart? Life if beautiful.....this moment is the most beautiful moment that has ever existed......we are it! We are infinite eternal beauty, Love and Joy. Look in the mirror and smile......love yourself....pet yourself....tell yourself that you are worthy and amazing......for you are!

The Lft-8 can be modded for much better sound and you can use a separate better woofer system, if you like. Will blow your mind. Bruce has some more sensitive planars now but he is not selling them yet. I want him to sell the new planars by themselves on a baffle....so we can just add our own crossover and woofs. He thought is was a good idea.....but is not happening......maybe some day. Meanwhile, you can use the Parts Express planars and/or the Radian Planars and beat most speakers on the planet (when combined with state of the art woofs).

I tried to just buy parts from Bruce as far as planar speakers to build a irs v but his explanation was you need the correct amount of tension to produce correct amount of . Have alot of bg .grs .strathern.other pro ribbons and also in the process of building and using electronic crossovers. Like rice's I am excited to hear of your progress keep us posted. You explained my irs v multiple drive 9 feet tall 4 to 6 inches each great spl.enjoy the music stay healthy .

Line array lives on.

@ricevs: Your comments are always welcomed by me (by the way, I still own the Audible Illusions Modulus 2 pre-amp you "modified" for me about 25 years ago. Modified is an understatement; it is a complete redesign, turning the full-function pre into a phono-only gain stage).

I did just as you suggest, using the GR Research/Rythmik Audio Direct Servo-Feedback OB/Dipole Subwoofer (which you at one point were using in your own loudspeaker design, mated to the planar-magnetic m/t drivers that are no longer available. I forget the name of the company that was making them. Danny Richie of GR Research is now offering his own version of that fantastic p-m tweeter.) in place of the stock woofer in the ET LFT-8b.

The combination of the ET LFT-8 planar-magnetic drivers (180Hz and above) mated with the OB Sub is one way to achieve near-state-of-the-art sound at a peasant-income price. IMO. Far superior to the Infinity RS-Ib’s I used to own.

@rpeluso My specific bad experience was with a PSA PerfectWave Transport ($4000 retail). I had three drive failures in 6 years. I played the unit around 4 to 6 hours per week.

I learned that PSA used the cheapest grade of computer drive (around $10) they could buy. These drives are not designed to spin a disc hour after hour. They are made to spin up a data disc, read the data, and then spin down. The choice of this drive for a $4000 transport is unforgivable in my opinion. They knew better and they simply cheaped out. By the time the third drive failed PSA no longer supported the unit and it became a boat anchor.

Second example is the PSA Power Plant 12. The review by ASR showed that the unit actually makes things worse for the downstream component but the biggest problem was that the "High Current" outlet actually reduces the wattage to the amplifier! But even more troubling was Paul's response, accusing Amir of using the wrong outlet. Paul even demanded an apology. Well, his employees (I won't call them engineers) corrected him and he had to admit that ASR did the test correctly. Did he offer Amir an apology? You guess the answer.

Third example is the PSA DirectStream DAC that uses an FPGA processor instead of a typical DAC chipset. This unit is quite expensive and has tested very poorly by Stereophile and ASR. It is actually one of the noisiest DACs available with very poor bit resolution. I won't go into the reasons for this but it is a perfect example of how a company tells a hyped story and charges a lot of money for a poorly engineered product.

For me, the above is enough to decide that I will avoid the PSA brand with prejudice. For the record, I don't trust Audioquest and several other brands that have put out products that have been demonstrated to actually make the signal worse than much cheaper alternatives.

Lastly, I don't want to start a war here. If owners of PSA products love them and hear wonderous sound quality, more power to them. My only advice is to be careful about the engineering design and build quality.

Thanks for the answer!

@8t-note

Have you actually listened to the DirectStream DAC? There are a lot of people who have including myself. I’ve compared it to ASR’s excellent measuring DACs. I was very obvious to me that there is a lot more to sound than numbers. I don’t have experience with other PSAudio products so I can’t comment.

Well, as the speaker designer at PS Audio, I thought I’d chime in.

I’ve never met Bruce Thigpen at any trade shows but, by all accounts he’s a genuis inventor and did a number of useful planar magnetic patents over the years, some of which are licensed by planar magnetic headphone companies among others.

However, the Eminent Tech speakers make me scratch my head. The crossover used is a total mess with broad overlaps and interference between the drivers (almost like there is no filter on the woofer and/or midrange). Cone breakup from the woofer is left unfiltered out and there is a bunch of interference from the resonances.

Also, sensitivty is almost 5 dB lower than specified (about 77-78 dB) and so it’s among the lowest on the market (even lower than magnapan.

stereophile measurements of LFT-VII showing driver responses with crossover

LFT-16 driver measurements

While the smaller LFT-16 looks intially better, the mid and woofer done integrate currently, even when switching driver polarity.

Also, when you have such a high crossover point to the tweeter, the midrange panel is beaming a lot before handing over to the tweeter and the off axis behavior is poor.

As far as crossover parts go, you guys selling crossover part upgrades as a side business have a biased viewpoint as to what is appropriate and perceptually significant. That being said, we use nice components in the FR5, appropriate for it’s price point, I think.

@cbrunhaver: You raise some justified issues, and make some excellent points.

The shallow crossover filters employed in the ET LFT-8 (1st-order) are also used by Magnepan in their planar-magnetic loudspeakers (PS Audio’s Paul McGowan’s reference speaker for quite a few years was the MG3.6, which he was very happy with in spite of it’s low-order filters). When Danny Richie of GR Research measured the MG3.7, he found a lot of frequency response irregularities caused by phase cancellations between drivers, a result of the large expanses of driver overlap (inevitable with low-order filters).

The ET LFT-8 (both b and c iterations) employs a 1st-order high-pass crossover frequency of 180Hz for the LFT-8 planar-magnetic midrange driver, so phase cancellation between woofer and midrange driver is not a problem (due to the very long wavelength of 180Hz). What IS a problem is the out-of-band woofer resonance (seen at around 1800Hz in the Stereophile frequency response graph), but that may be eliminated in the LFT-8b by installing a cap onto the woofer, shunting the high end response of the woofer to ground (as detailed in a few posts in the Planar Speaker Asylum forums). That problem is eliminated in the LFT-8c, which has a different (dipole) woofer system. I eliminated the problem by using the Rythmik/GR Research OB/Dipole woofer system in place of the LFT-8b’s stock woofer (easy to do, as the 8b has separate woofer and planar-magnetic driver binding posts), which transforms the LFT-8b into a 100% OB/dipole design.

The criticism of the 1st-order high-pass and low-pass filters located at 10kHz IS quite valid. A 10kHz wavelength is only approximately 1.36" long, so small movements of the listener’s head can result in frequency response changes resulting from phase cancellations between the midrange and tweeter drivers. I’d love the hear the LFT-8 with a lower midrange-to-tweeter x/o frequency, and/or steeper filter values (perhaps 4th-order, as I believe Siegfried Linkwitz employs in his OB/Dipole designs). The phase relationship between tweeter and midrange drivers in the LFT-8 may be adjusted by small changes in loudspeaker toe-in.

I don’t know where the 77-78dB sensitivity figure came from, but it is not accurate (83-84 is more like it). The LFT-8 infact requires significantly less power that do Maggies (I have both). Steve Guttenberg found 50 watts to work pretty well with both the 8b and 8c. And if you bi-amp the speaker, the planar-magnetic driver itself presents an 11 ohm load to the amp, great for tubes

Regardless of all the above, the fact remains that the ET LFT-8 reproduces 180Hz up to 10kHz WITH A SINGLE PUSH-PULL PLANAR-MAGNETIC DRIVER (without a crossover in that frequency band!), resulting in high coherency and transparency, low coloration sound. I better wrap it up here, before I’m once again accused of shilling for Eminent Technology and Bruce Thigpen.

“The criteria for loudspeaker choices” title suggests a general criterias or what each person what they do for evaluation, but the OPs content narrowly emphasizes ET a so seems like shilling/promotion.

The criteria I use along with many/most audiophiles is to “use our ears” to choose loudspeakers.  More specifically I demoed/purchased a neutral linear full range loudspeaker running SS, and a 100db loudspeaker specifically to explore tube magic starting with the flea watt 300b amp.  Future loudspeaker purchases might include MBL omnis (always sound great) to fill in a shared room, MoFi SoucePoint 10 (huge fan of speaker guru Andrew Jones), and Devore Orangutan O/96 (maybe the most musical speaker I’ve demoed).  I’m trying to justify spending for a 3rd system the great matching Harbeth+Hegel.  

There are many good/great sounding loudspeakers, but which loudspeakers  to bring home aka spend significant money on preferences are highly subjective.  

@kennyc: The title of the thread was made in relation to what PS Audio had to say about planar-magnetic drivers, which they choose to employ as tweeters in all their loudspeaker models. In their promotional literature for their speakers, they cite all the ways in which p-m drivers meet their criteria for achieving superior quality reproduction of high frequencies (reread the op to refresh your memory if necessary).

The question I therefore asked was: If planar-magnetic drivers meet PS Audio’s criteria for superior reproduction of high frequencies, why not use a planar-magnetic driver for midrange frequencies as well? There are only a very limited number of loudspeakers employing p-m drivers to reproduce midrange frequencies, one being Eminent Technology. Another is of course Magnepan. I currently own both Magnepan and Eminent Technology models, and because everyone already knows about the former and few do about the latter, I felt compelled to once again bring the ET LFT-8 to everyone’s attention. If that now qualifies as shilling, so be it.

Everyone has their own criteria for choosing a loudspeaker, I posted this thread in response to the criteria stated by PS Audio as the reason for them choosing a p-m tweeter, not as a means of myself making the case for the superiority of planar-magnetic drivers or loudspeakers. I also own ESL’s (QUADS), but didn’t bring them into the discussion as PS Audio doesn’t use ESL drivers, nor make any claims as to their ability to reproduce music.

One listener who DID bring the subject of ESL’s into his review of the ET LFT-8b and 8c is Steve Guttenberg. In his reviews he states that he doesn’t care for the sound ESL’s make, preferring his dipole panel speakers to be of planar-magnetic design. He then goes on to say that he found the sound produced by the two ET models to be superior to that produced by every ESL he has heard, as well as all Magnepan’s he has had in his listening room.

I hope this post makes clear my motive and intent. I did my best to make it so!

I don't put much, if any stock in marketing blurb. PSA was on the cusp of releasing a floor standing speaker, but the showing at Axpona (pre covid) got so little attention that the company threw out that design and started over from scratch. The FR lie is much more of an attention getter than that previous box. This lineup looks like a legitimate investment and effort.

Well, I don’t have an axe to grind against Bruce or any of his products but was just commenting on some of the measurements from stereophile.

In fact, while they are in the same price category, I don’t think it makes sense to compare a large open baffle line array to a small stand mount.

however, i did want to target some of the technical analysis.  As you mentioned above, wavelengths are very small around 8 kHz and a lower crossover point would be beneficial.

regarding the sensitivity, John Atkinson commented that the LFT-VIII was 4.7 db lower than his LS3/5A’s 82.5 dB and to this puts the speaker around 78 db/2.83V

https://www.stereophile.com/content/eminent-technology-lft-viii-loudspeaker

Paul writes our ad copy and the website and it can be a little hyperbolic at times as we’re trying to emphasize the positive attributes of a product.  However, I think the speakers are very competitive performance wise to a lot of big names and have some unique performance attributes.  Our bookshelf speaker in particular is getting great feedback and will be on the cover of the October issue of hifi news and in an upcoming stereophile, I believe.

they men

@cbrunhaver: The sensitivity measurement Atkinson got was for the original iteration of the LFT-8, reviewed in Stereophile way back in 1993. In 2007 the original woofer and crossover were replaced with new ones (and renamed the LFT-8a), which raised the speakers sensitivity to it’s current 83dB spec. When the original tweeter was replaced with a new one, the speaker became the LFT-8b.

As other owners have found (as did Steve Guttenberg), while the LFT-8b has a rated sensitivity very close to that of Maggies, the ET’s require far less power than do Maggies (As I stated above, I have both). But the way to run the LFT-8 is bi-amped; when run that way the p-m panel itself is an 11 ohm load to the amp, and 50 watts is plenty for it alone. The woofer of the 8b can be powered by any ol’ amp, preferably a solid state one

By the way everyone, Steve Guttenberg recently reviewed another large planar-magnetic loudspeaker, made by the French company Diptyque. He likes it even more than the ET LFT-8b/c, but it costs far more, I believe four times the price of the LFT-8b.