AudioCircle
Audio/Video Gear and Systems => Low Wattage Systems => Topic started by: Emil on 26 Apr 2019, 06:43 pm
-
On looks alone it's hard to take this speaker seriously but it did get a nice review in 6 Moons.
https://6moons.com/audioreview_articles/tekton/
(https://www.tektondesign.com/uploads/9/8/4/7/98478018/the-perfect-set_orig.png)
https://www.tektondesign.com/the-perfect-set.html
$1800 DELIVERED with a 60 day trial.
Return cost is on you and no doubt expensive
Anyone hear a pair?
-
I could put some of these tweeters on top and back.
Two ports are a pro audio solution, usually in hi fi is used just one larger duct to reduce breath noise.
-
I could put some of these tweeters on top and back.
Two ports are a pro audio solution, usually in hi fi is used just one larger duct to reduce breath noise.
Only has one tweeter surrounded by midrange drivers
-
Only has one tweeter surrounded by midrange drivers
At first glance looks a two way speaker.
Do you mean say it use a 3 ways xover?
What are the freq cuts?
-
Only has one tweeter surrounded by midrange drivers
I may be wrong :lol:
-
"Proprietary controlled directivity - acoustically superior proprietary polygon-oriented, triple-ring radiator high frequency array. This array disperses a precisely focused acoustical power pattern of that of a horn or waveguide without the audible ringing influence of horn flare walls constraining the soundwave for acoustically superior mid-range high frequency performance "
-
In general, all Tekton models get good reviews.
I've never personally heard Tektons, but my buddy raves about his pair of Impact monitors, and he's been at this game a looong time and has owned some really excellent speakers.
-
"Proprietary controlled directivity - acoustically superior proprietary polygon-oriented, triple-ring radiator high frequency array. This array disperses a precisely focused acoustical power pattern of that of a horn or waveguide without the audible ringing influence of horn flare walls constraining the soundwave for acoustically superior mid-range high frequency performance "
Any patents or science to back that up? :dunno:
-
Any patents or science to back that up?
U.S. Patent 9247339
-
If you are interested, there is a thread on Audiogon on this specific Tekton model started by the reviewer from the aforementioned article. Likewise , there are several other Audiogon threads relative to other Tekton models, including one that has over 5000 posts. Just passing this along so you know and have an interest. I don't own Tektons so I am not mentioning the threads to steer you towards the brand
-
There is a thread on DIYaudio discussing how the tweeter array is set up. The original poster detailed the crossover which gives insight into how the array is designed to function.
-
Hey!
OK, the post's headline caught my eyes :lol: And the last paragraph of the review is quite a statement there. I'm a single driver kinda guy, you know the wide range no crossover thing. But yes I would love to hear these speaker. The 60 days trial is great bu wonder how much is will cost to ship them back from NYC?
Anyway, all those tweeters reminded me of looking at spiders :icon_lol:
Buddy
-
U.S. Patent 9247339
The patent imho does not back up his contention that this is a CD design. In fact, the patent is a little strange and essentially says that light weight transducers should be used for the “faithful reproduction of musical instruments, etc...
https://patentimages.storage.googleapis.com/ef/3b/8b/91cfa120a70f05/US9247339.pdf
As much as it is challenging to obtain a patent, and expensive as well, it is important to see if said patent is directly relevant and/or supportive and if he has indeed improved loudspeaker design as it exists today.
I don’t see it as so. I see his assertion being obvious and only a small aspect of loudspeaker design. What I think he has done is to patent that assertion for marketing purposes.
That being said...
The collection of tweeters is FAR more interesting. It is similar to DB Keele’s CBT array but he couldn’t /hasn’t patented that because well...it’s Keele’s idea! Keele’s stuff is now being licensed and sold by JBL and Parts Express.
Post #12 on this diyaudio thread gives all details:
https://www.diyaudio.com/forums/multi-way/336743-help-understanding-tekton-tweeter-array-schematic-2.html#post5764116
I would like to see detailed polar plots and off axis curves. I have a feeling they will look decent although not as perfect as the best waveguide based designs. Still, I am happy to see yet another method in trying to obtain a CD response.
The collective driver array isn’t exactly new. Other than Don Keele, it’s also described in Earl Geddes book and has been a component of the Legacy Whisper (by Bill Dudleston) for at least 20 years, except he didn’t use low passed tweeters as Tekton’s Alexander has done.
And let’s not forget Donald North’s (engineer at Aurasound) loudspeaker design: http://www.dnaudio.com/DNA%20Speaker.html
Best,
Anand.
-
And let’s not forget Donald North’s (engineer at Aurasound) loudspeaker design: http://www.dnaudio.com/DNA%20Speaker.html
$20,000 for a few drivers mounted on boards. Sheesh.
-
$20,000 for a few drivers mounted on boards. Sheesh.
The example wasn’t listed for “best value” but for an example of a concentric array exhibiting controlled directivity.
But that triode active XO probably wins a few tube and SET enthusiasts...
Best,
Anand.
-
The patent imho does not back up his contention that this is a CD design. In fact, the patent is a little strange and essentially says that light weight transducers should be used for the “faithful reproduction of musical instruments, etc...
https://patentimages.storage.googleapis.com/ef/3b/8b/91cfa120a70f05/US9247339.pdf
As much as it is challenging to obtain a patent, and expensive as well, it is important to see if said patent is directly relevant and/or supportive and if he has indeed improved loudspeaker design as it exists today.
I don’t see it as so. I see his assertion being obvious and only a small aspect of loudspeaker design. What I think he has done is to patent that assertion for marketing purposes.
That worked out quite well for Bose. :lol:
I don't know why, but I find it hard to take the Tekton brand seriously.
-
Here is one for sale. Purchased in April 2019.
https://www.usaudiomart.com/details/649517819-tekton-the-perfect-set-15-speakers/
Best,
Anand.
-
What does the impedance curve look like?
This is the version with 2 woofers (still called a Double Impact):
(https://www.stereophile.com/images/718TekIMfig1.jpg)
As epected it goes to 4 ohms or less where there ar e2 woofers, but the big bump at the XO is not going to make a SET happy.
dave
-
I'm with Anand on the patent/s.
Best I can tell the tweeters are for just chopping up the sound into something new, because really low THD and tweeters with most crososvers and such kinda stick out like a sore thumb often. There's lots of comb filtering and stuff going on some of the models. The double impact might accomplish a minor amount of what they say.
-
What does the impedance curve look like?
This is the version with 2 woofers (still called a Double Impact):
(https://www.stereophile.com/images/718TekIMfig1.jpg)
As epected it goes to 4 ohms or less where there ar e2 woofers, but the big bump at the XO is not going to make a SET happy.
dave
Dave,
Great point of course. Manufacturers state stuff like "nominal 8 ohm impedance." What in the world does that mean? Nuts. The fact is, unless the speaker is measured by Sphile, Soundstage!, etc...you will not know. Most manufacturers don't reveal it.
I measure all my speakers for both impedance and phase which gives me an extraordinary amount of information and suggestions for amplifier compatibility as phase angle and impedance are both important as is sensitivity over a given frequency range. In other words, I don't care if a speaker is 2 ohms at 20 Hz or 20khz but I do care about the impedance and phase curve over the region where most music is played, i.e. 40Hz to 10khz.
With the Tekton Double Impact Monitor measurements you have posted, a typical SET amplifier will sound excessively forward in the upper midrange (due to the high impedance), and lacking in the lower midrange and upper midbass. The frequency response curve will most definitely be affected in that range if using an SET to drive that speaker.
But honestly dave, most folks don't care about those details.
Best,
Anand.
-
I think there is no SET friendly speaker with xover, they are awful.
-
There are certainly some that get the impedance flat… which is the key for any speaker used with any amp that has a hihish output impedance (most SETs). way more important than (often over-) rated efficiency.
dave
-
The famous among tube lovers Klipsch RF7II by 101dB sensitivity and strong bass, has a similar impedance(black) and phase(green) chart, the 2 way xover are 1100kHz, seems the minimum impedance is under 4Ω at 150Hz due two parallel woofers, its beyond me why this speaker are rated 8Ω.
Wonder what is the 3kHz peak?
(https://www.audiocircle.com/image.php?id=194054)
-
Dave,
Great point of course. Manufacturers state stuff like "nominal 8 ohm impedance." What in the world does that mean? Nuts. The fact is, unless the speaker is measured by Sphile, Soundstage!, etc...you will not know. Most manufacturers don't reveal it.
I measure all my speakers for both impedance and phase which gives me an extraordinary amount of information and suggestions for amplifier compatibility as phase angle and impedance are both important as is sensitivity over a given frequency range. In other words, I don't care if a speaker is 2 ohms at 20 Hz or 20khz but I do care about the impedance and phase curve over the region where most music is played, i.e. 40Hz to 10khz.
With the Tekton Double Impact Monitor measurements you have posted, a typical SET amplifier will sound excessively forward in the upper midrange (due to the high impedance), and lacking in the lower midrange and upper midbass. The frequency response curve will most definitely be affected in that range if using an SET to drive that speaker.
But honestly dave, most folks don't care about those details.
Best,
Anand.
Yeah, I've just recently had an illuminating experience along these lines with my Zu Omen Dirty Weekends. Zu started offering resistors for sale to place across the binding posts to bring more uniformity to the impedance curve. This led me to look into the impedance curve for the first time, and found this:
(https://www.audiocircle.com/image.php?id=194063)
https://www.zuaudio.com/diy/loading25r
So while Zu gives the characteristic impedance, I thought I'd calculate the high and low impedances by hand based on that Superfly graph, since the main driver in the DW's is pretty much the same as the Superfly, with different cabinet loading. I ended up going with two 25 ohm resistors, which my my calculations brought the high impedance down from 45 ohms to around 9 ohms. And the low impedance only dropped to around 4 ohms. So, a 4-9 ohm range from a 7-44 ohm range.
But most crucially, it muted that gradually rising impedance from midbass to upper midrange by quite a lot. And sure enough, the speakers don't sound nearly as uptight and constricted on my 845 SET amp, which would be the effect of a frequency response imbalance toward the upper midrange, but now have opened up and breathe nicely. I used to need to use a solid state amp with these speakers to get a satisfying presentation. No longer.
-
Yeah, I've just recently had an illuminating experience along these lines with my Zu Omen Dirty Weekends. Zu started offering resistors for sale to place across the binding posts to bring more uniformity to the impedance curve. This led me to look into the impedance curve for the first time, and found this:
So while Zu gives the characteristic impedance, I thought I'd calculate the high and low impedances by hand based on that Superfly graph, since the main driver in the DW's is pretty much the same as the Superfly, with different cabinet loading. I ended up going with two 25 ohm resistors, which my my calculations brought the high impedance down from 45 ohms to around 9 ohms. And the low impedance only dropped to around 4 ohms. So, a 4-9 ohm range from a 7-44 ohm range.
But most crucially, it muted that gradually rising impedance from midbass to upper midrange by quite a lot. And sure enough, the speakers don't sound nearly as uptight and constricted on my 845 SET amp, which would be the effect of a frequency response imbalance toward the upper midrange, but now have opened up and breathe nicely. I used to need to use a solid state amp with these speakers to get a satisfying presentation. No longer.
Which brings up a very relevant question: shouldn't the designers of said speaker have figured this out (and addressed it) prior to releasing this for sale? I wonder what happened to the concept of releasing a speaker when it is truly ready for prime-time, not before. :duh:
-dGB
-
There are certainly some (speakers with crossovers) that get the impedance flat… which is the key for any speaker used with any amp that has a hihish output impedance (most SETs) which is way more important than (often over-) rated efficiency.
Yes, that is very true. The curve below isn’t as bad as it looks, and despite having a crossover and a bump around 900 Hz, these speakers with a SET did the mids and top end better than FR single driver I’ve heard.
(https://www.audiocircle.com/image.php?id=194061)
-
Which brings up a very relevant question: shouldn't the designers of said speaker have figured this out (and addressed it) prior to releasing this for sale? I wonder what happened to the concept of releasing a speaker when it is truly ready for prime-time, not before. :duh:
-dGB
This is the usual procedure in home audio, compact disc was made by 2 big corp and hi freq sound quality are poor, the whole system barely works, this happen even in military jets, some models are famous by its design flaws.
-
Which brings up a very relevant question: shouldn't the designers of said speaker have figured this out (and addressed it) prior to releasing this for sale? I wonder what happened to the concept of releasing a speaker when it is truly ready for prime-time, not before. :duh:
-dGB
Bingo. Which is why I am keeping my current speakers!
Best,
Anand.
-
Bingo. Which is why I am keeping my current speakers!
Good idea, better to wait for the MK-II version. :lol:
-
If anyone wants to hear this tweeter array let me know. I use the Impact Monitors with a pair of Rythmik subs. I’m in Charlotte, NC.
-
If anyone wants to hear this tweeter array let me know. I use the Impact Monitors with a pair of Rythmik subs. I’m in Charlotte, NC.
I’m there!
We need to hang out anyway. I think I have your email too and I am curious about Eric Alexander’s designs and approach.
Best,
Anand.
-
Great, Anand! Shoot me an email and let me know when's best for you.
-
I think there is no SET friendly speaker with xover, they are awful.
Would it be better to have a SET amp for your main driver, then a separate amp/woofer to handle the lows..?
V...
-
That would get rid of the passive XO which is most often the cause of ugly impedance above resonance.
This is the rational behind WAW (Woofer Assited Wideband / AKA FAST). XO at line level typically at 200-400 Hz, it also gets rid of the incoherence invoked by a tweeter + midbass.
dave
-
Would it be better to have a SET amp for your main driver, then a separate amp/woofer to handle the lows..?
V...
I believe most music lovers will like this approach.
-
I tend to believe Eric Alexander knows what he's doing. At least far more than
most armchair experts that are often ready with an opinion.
Just my opinion :)
Hibuck...
-
I believe most music lovers will like this approach.
Agreed...
-
I favor the approach of letting the loudspeakers to speak for themselves. The opinions of people who have never heard the speaker are worthless. The opinions of those who have are just that, opinions. Everyone's taste in loudspeakers are personal. Tekton's policy of a 60 day free trial is quite generous and uncommon in the audio industry.
-
I agree its always best to actually hear a stereo component before forming an opinion on sound quality but I've found the discussion here on the history of this type of speaker and its inherent strengths and/or shortcomings to be helpful. Especially since the discussion has been civil. They clearly know more about speaker design than I do and that's what these boards are for.
-
...... Tekton's policy of a 60 day free trial is quite generous and uncommon in the audio industry.
It speaks to the mfr's confidence is his product.
Off the top of my head, Buchardt and Zu also offer generous risk-free audition periods. I believe Buchardt even pays shipping in both directions. Virtually unheard of in the industry.
-
It speaks to the mfr's confidence is his product.
Off the top of my head, Buchardt and Zu also offer generous risk-free audition periods. I believe Buchardt even pays shipping in both directions. Virtually unheard of in the industry.
A quick check over at the UPS website, returning a pair of these 70 pound speakers to Utah from NY will cost roughly $220. Not an insignificant amount. Something to consider before giving them a whirl .
Important to have the customer have some skin into the game. Free return shipping can lead to abuse but on the other hand it can also get your speakers into more peoples homes
-
I tend to believe Eric Alexander knows what he's doing. At least far more than
most armchair experts that are often ready with an opinion.
Just my opinion :)
Hibuck...
LOL! He knows he’s building speakers, he’s got about 30 different models to choose from that are currently available on his website. Most brands don’t offer anywhere near that kind of selection. How much R&D goes into all of that?
But is “The Perfect SET Speaker” really perfect, or even compatible with SET amps just because he says so? Has science evolved to the point where everything now is just a matter of opinion?
These are just observations and questions. No opinions expressed or implied. :dunno:
-
Some people don't seem to understand what science is and more importantly, at times, what it is not. :wink:
-
I have Double Impact SE speakers so not the same as the thread title units but regardless I really like them and are happy with them. I agree Eric has a lot of speakers that are in similar price ranges so his marketing does confuse me a bit
The units I have are sound great with my Audio Note Kit 300B's and also sound great with my Pass solid state equipment. I would buy them again.
-
I have a pair of Perfect SET-15's. I was using them while building my horns and was pleasantly surprised at the sound and dynamics fed by my 300B SET monoblocks.
-
Interesting review from NRD:
https://youtu.be/2w8jnkEfrww
Best,
Anand.
-
Some people don't seem to understand what science is and more importantly, at times, what it is not. :wink:
Gravity. :wink:
charles
-
Interesting review from NRD:
https://youtu.be/2w8jnkEfrww
Best,
Anand.
Thanks Anand for the link. After watching the video and reading the comments I am shaking my head...
-
What a mess.
-
Some people don't seem to understand what science is and more importantly, at times, what it is not. :wink:
A democracy! :rotflmao:
-
Official Science is just a opinion.
-
Tekton sales are VG. Someone is doing something right. Try before you comment. Very easy solution. Tyson correct a "mess"
charles
-
Well he does have his own "personal reviewer" Terry London touting every new model as the next coming both on Audiogon and now 6 Moons.
-
Seems like the snark level is rising here.
Just sayin'
Hibuck….
-
...............................
-
Deleted
-
I have owned several Tekton speakers over the years and currently have 3 of the “cough,cough” 20 flavors in house (Lores, Double Impacts, and Perfect SET). I would have to say the Perfect SET is the most underwhelming of them all. I really loved my Lores but since they were 1st generation and had been mauled by my cats and moves over the years I decided to try the DI SE model and I have to say they are some of the finest speakers I’ve heard. Hell, they bested a pair of Super V’s Gary Dodd had at his house for years from what I remember. But, since this is a Perfect SET thread I’ll stay on point. There is something “not right” with them!?! Extended soundstage is non existent and imaging is terrible. With the Double Impacts you can pinpoint every instrument and the soundstage is GIANT and stretches wall to wall. The Lores were actually decent at this as well...just nowhere near the DI’s but they are double the cost. Not sure what’s up with these Perfect SET’s!?!? Maybe it’s my room. I’ll report back when I have a chance to move them downstairs into the main room where the DI’s are.
-
Regarding Super V's.
Extended soundstage is non existent and imaging is terrible.
I beg to differ, greatly. I get STUNNING imaging and soundstage. I suppose if you had them close to the wall then I can see it. Imaging is very important to me and I know how to get it, usually. The Super Vs image as good as anything I have owned before, and better than most.
Rocket Ronny
-
I believe he was referring to the Tektons, not the Super V’s
-
I believe he was referring to the Tektons, not the Super V’s
Correct, I was referring to the Perfect SET speakers and their inability to throw a nice soundstage. The Super V's at Gary's were the first experience I ever had with a speaker throwing an AWESOME soundstage. That was in like 2008???? :P
-
If anyone wants to hear this tweeter array let me know. I use the Impact Monitors with a pair of Rythmik subs. I’m in Charlotte, NC.
Very interested in your impressions of this setup. I'm seriously considering ordering Impact Monitors and pairing with Rythmik subs. For context any comparisons you can offer with other speakers you've owned or listened to would be much appreciated. Also, my focus is on music listening, so HT isn't a factor for me.
Thanks in advance.
-
I have Impact Monitors with 4 subs(the swarm setup).They are dynamic and will play loud with no distortion.They can reproduce micro dynamics and nuance very well -it depends on what you have upstream from them.I recently compared them head to head with a pair of Klipcsh Heresys which were a bit faster sounding with a similar midrange,but hashy on top and the upper bass was a tad less tight.
My room is 16x17,GIK room treatments,all tubed equipment -Tubadour dac,LTA MicroZotl 2 pre,Aric Audio Transcend 40watt amp,Audio Envy ics and pcs,Analysis Plus Solo Crystal Oval 8 spcs.
I like a live 'you are there' sound and I listen to mostly acoustic and electric rock and blues.
I hope this helps!
-
I have Impact Monitors with 4 subs(the swarm setup).They are dynamic and will play loud with no distortion.They can reproduce micro dynamics and nuance very well -it depends on what you have upstream from them.I recently compared them head to head with a pair of Klipcsh Heresys which were a bit faster sounding with a similar midrange,but hashy on top and the upper bass was a tad less tight.
My room is 16x17,GIK room treatments,all tubed equipment -Tubadour dac,LTA MicroZotl 2 pre,Aric Audio Transcend 40watt amp,Audio Envy ics and pcs,Analysis Plus Solo Crystal Oval 8 spcs.
I like a live 'you are there' sound and I listen to mostly acoustic and electric rock and blues.
I hope this helps!
Not sure if that was a response to my post, but very helpful. I am quite interested in the live as if you're there sound, which is one of the aspects I've read about the Tektons that's appealing. Also listen to a lot of acoustic music. I currently have Gallo Stradas and subs, which have exquisite imaging and 3D soundstage. But I go through phases of wanting to explore other options. Thanks for the info.
-
Where can I find an explanation of how the 7 tweeter polygon arrays in their more expensive designs work?
I admire Eric from his original speakers (Lore, etc.) but have never heard one and being a purist am leery of many of his later work (small vertical line tweeter arrays, 15 tweeter MTM arrays, even whizzer cones).
-
Where can I find an explanation of how the 7 tweeter polygon arrays in their more expensive designs work?
I admire Eric from his original speakers (Lore, etc.) but have never heard one and being a purist am leery of many of his later work (small vertical line tweeter arrays, 15 tweeter MTM arrays, even whizzer cones).
I think this might explain his approach a little bit more.
https://www.stereophile.com/content/tekton-design-impact-monitor-loudspeaker
I think with more driver units, the designs gain more sensitivity and more sound impact. Not that most people could benefit from the upscaling of the sound. I have very little to gain from such design as my listening quarters are rather small.
-
Where can I find an explanation of how the 7 tweeter polygon arrays in their more expensive designs work?
It is dissected on a thread at diyAudio. Estentially it is a 1 + 6 array with the 6 surrounding tweeters only coming in on the bottom. The spacing does require significantly compromising on the ideal quarter-wavelength of less centre-to-centre distance.
dave
-
I think this might explain his approach a little bit more.
https://www.stereophile.com/content/tekton-design-impact-monitor-loudspeaker
I think with more driver units, the designs gain more sensitivity and more sound impact. Not that most people could benefit from the upscaling of the sound. I have very little to gain from such design as my listening quarters are rather small.
Thanks for the link. :thumb:
As I thought, the array is 2-way, which as one could easily imagine struggles to cohere well near-field, and with the spread out mid/woofers has severe comb effects below 1,000 Hz. And has bass interaction issues with nearby walls, so you say - not well suited for small spaces. Have little tolerance for placement fussy speakers or ported designs that require stuffing. Plus the cabinet has resonances. And efficiency is very over-stated. But they do seem to be impactful.
The whole concept, of replacing a midrange driver with multiple tweeters seems odd. The Tekton catalog reminds me of another vendor who keeps reusing the same drivers in a variety of "designs", smacks of fitting designs around a very small parts bin. If your company lacks the resources to build drivers in-house (very few) and you aren't satisfied with off the shelf, the next best approach is to have top drawer driver manufacturers custom design/tweak drivers for you. Ascend Acoustics is one such company that follows that approach.
-
in my search for a good higher sensitivity speaker I just order a set of Tekton Lore Reference I can't wait to hear them on my tube amps.
-
Pretty ingenius whoever came up with the midrange tweeter array. Enjoyed the explanation here: https://www.diyaudio.com/community/threads/help-understanding-tekton-tweeter-array-schematic.336743/#post-5764116
No experience with Tekton midrange tweeter array, but I have spent a few hours listening to their two way Lore. I purchased a used pair of Tekton Lore's as a gift for my daughter. Since they were used I paid $500 and was really happy with the sound per $ considering it is a full range speaker. Brought over with a receiver I had laying around and set up. When I visit playing vinyl impressed with the sound quality their modest setup provides.
Surpised at the cynism this thread has aroused. For a second I thought I was on the ASR forum, oops its even bringing out my snark :D. Hope this is an outlier as AC has been a great place.
-
Over the years Eric Alexander has come up with some interesting SET friendly designs. These hybrid open baffles being one of them. The H-frames made good speaker stands as well as providing some needed bass support.
(https://www.audiocircle.com/image.php?id=48428)
-
We betaed that design. It flopped. In that interaction i gained no respect for Alexander.
He has been successful. I do not like the huge spacing required for those tweeter and midrange arrays.
dave
-
It is beyond my comprehension why hi-fi brands dont use coaxial speakers like the excellent Morel or the Beyma.
-
A number of months back, I picked up a used pair of Tekton electrons as a second system. I have been very happy with them, after proper placement, the bass is tight, the mids are very clear and top to bottom they sound great. I DO prefer my Spatial M3TS' since the 15" woofers do better justice than the 8" on the tektons, but they are no slouches.
The mids on the Tektons are fast and at times bright, but this problem was solved by replacing the 52(!) screws holding the drivers with brass screws. Some of you may balk at the screw replacement, but you use your ears and not your assumptions, you may hear a difference.
-
An early Tekton Fostex speaker before Eric switched to Eminence drivers. Efficient enough to be driven by a couple of single ended watts.
(https://www.audiocircle.com/image.php?id=252852)