Higher Efficiency Speakers


I am going to start my quest for speakers. My room is 13.5x13.5 but open on two sides... so not an ideal space. But never the less this is what I have to deal with.  I have a set of Vandersteen 2ce Sig ii but would like to upgrade. Was thinking about something horn. But seems when you go that route it gets way out of my price range.  Thought maybe look around for some Used Vandersteen Quattro CT but budget starts to stretch at that point. Like to stay under $10,000. What would be good speakers to look for to demo? If my room was alittle bigger.  I’d almost go the other way, and look at Small Maggie’s and Monostrap my amps.
System
Atma-sphere M60
Atma-sphere UV-1 ( Probably the most Modded. Will be at the end of the month. Lol) 
Bel Canto Dac

128x128pstores
Since it takes more power to drive bass drivers, I wonder why all speakers are not built with a built in amplifier.  If that were the case wouldn't you just need to deliver a pure signal and allow the on board amplifiers to generate the sound?  Wouldn't this in turn generate less distortion?
I got the sensitivity number from the Charney website...I think it has something to with the horn design. There is very little resistance from back waves in the chamber and the tractrix design of the horn. Just a guess, Charney could better explain it. I have owned a few Omega designs and the RS7 shines in the Charney horn. Very low excursion hard to see the driver move during play back.
@rodge827 - Those speakers look great! I use Omega HO with a SET amp and it's magical. How does the sensitivity increase w the Charney utilizing the Omegas RS7 driver vs an Omega with the RS7 driver? I am genuinely curious. 
Another shout out for Charney Audio! I have a pair of Maestro's with the Omega RS7 driver ($5,400) in my 11x15x8 room. Sensitivity is 100db so low powered SET amps are the way to go. I have ANK Interstage 8w300b amps and can't get enough of what this combo can do. In the room performers, drawing you into a deep, wide, and engaging soundscape. If your within a couple hour drive to Central NJ make an appointment with Brian. Very well worth the experience!
http://charneyaudio.com/
interesting...  almost sounds like the woofers were internally wired out-of-phase
fdottore……………………

I had a pair of the Von Schweikert VR33 which are the same but with the lesser quality crossover and not set up for bi-wiring.  One of the worst speakers I ever owned.  I got sucked in by the ad that a 3750.00 speaker sounds as good as a 15,000 pair, and also because Greg Weaver who I respect as a reviewer gushed all over them.  In my living room, 5 inches from the wall, there was absolutely NO bass, nada, nothing.  I moved them and the furniture all over the living room and yet the bass was not there.  This was after having lived with a pair of Vandersteen 2ce sig speakers for a few years.  My non audiophile wife remarked on many occasions if I had turned the bass off.  I kept them for a year and found myself not listening to the system at all, preferring to listen to my office system upstairs instead.  I finally sold them for 1400.00 at a huge loss and bought GE Triton Ones and the bass was back.  I liked the GE speakers so much that when the Triton References came out I bought a pair of them and moved the Triton Ones upstairs to my office system.

The funny thing is the guy I sold the Von Schweikerts to LOVED them and gave me a personal call, thanking me for selling them to him.  Go figure.
VON SCHWEIKERT VR-35 MkII speakers, under $7k factory direct, 90db efficient and designed to be placed right up against the rear wall (as close as 3").
I'm intrigued by those Pure Audio Project sets.  Even that big Quintet with 4 15" woofers is under $10k... and decent at 96db sensitivity.
Lots of speaker to choose from and some are good sounding. The important thing is to keep your amp set up the way it is. Simpler is better, lots of speakers will work just fine.
Second keeping Decware in your sights, but a different model:

http://www.decware.com/newsite/HDT.html

I've had my pair since 2004, and have never looked back. Drive them w/ a Decware SE84CS from 2004. Most musically engaging set-up I have ever heard.

Had SS driven Sonus Faber Guarneri Homage w/ Rel Stadium lll sub prior to that, and didn't miss it a bit.

The HDT's are world class.


Another vote for a look at Tekton here. 60 day trial is offered on those. You really can't decide on a speaker until you have it in your room powered by your unique front-end components. Although all of the Tekton line is extremely efficient, Eric just released a speaker aimed at the SET applications. https://www.tektondesign.com/the-perfect-set.html You may want to do a trial on that. And no, they aren't $10K but I assure you everything Tekton does performs WAY over their cost. I trialed the DIs just to prove to myself the hype wasn't true on them when they were first released. Just the opposite happened. In fact I liked them so much I returned them and purchased Ulfberhts. An amazing speaker for $9K if you have the room for something that large.
Take a look at the Klipsch cornwall's that are totally upgraded on audiogon currently they work out standing with tube equipment and solid state and  you can adjust the crossovers to the sound you prefer.I took great care upgrading these.
There are multiple choices in the Tekton line that would check off on all your boxes......big time.
Hi pstores, I had the same Vandersteens you have, as well as KEF 105 Reference 2s, Thiel CS-7s, B&W Matrix 2's, and upgraded the caps and resistors in line with the audio path in all but the CS-7s, because before I got around to the CS-7 crossovers I bought some Audio Nirvana AN15 Alonco Classic full range drivers. I purchased a DS2 preamp from Don Sachs, and so I knew that he knew his audio, and he recommended them. David Dicks, the owner of Audio Nirvana, almost convinced me that he was completely full of it because of the old addage that if it sounds too good to be true, it probably isn't. I had inexpensive unfinished cabinets made so that they were done before the drivers arrived as I was pretty confident that I would be returning them. Once they arrived, while over all they didn't sound that good, the vocals immediately blew me away. I ran them 24 x 7 until I had well over 100 hours on them, and they certainly needed it! They began sounding pretty good, better than anything I have ever had in my system, even better than the Quad 57's which I loved, but they had no volume, no bass, and like all the Acoustats that followed them, compressed dynamics. None the less, what the Quads got right made them some of the most musical speakers that I had ever owned, but I couldn't live with their limitations. Anyway, these sound better than the Quads. I had no idea how badly even a crossover with the best components suck. David offers a 30 day return policy, so get the enclosures made first, and use SS gear so you can drive them for at least 100 hours before taking them seriously. After that, using your best gear, give them a reasonable serious listen. They'll continue to improve, though after 500 hours or so I am not sure that you'll really notice much more improvement, but allegedly the more you play them the better they sound indefinitely, but I can't speak to that. I can say that to better them you'd have to spend a boat load of money. I used V-Caps, and or Mundorf Silver Gold capacitors to bypass the crossover caps in my speakers, so I was getting about as much as could be gotten through the crossovers, but some very good speakers were embarrassed by the AN speakers. They do have detractors, but I have no issues with them whatsoever. For under 2K, if you go for nice cabinets, they are the best sounding speakers I have ever heard.
Earlier in this trail somebody suggested having 100 dB efficiency speakers would give a freedom to chose from a wide range of amps. I did just that and am now running 1W/channel (yes, 1W) Linear Tube Amp called microZOTL2 with Teresonic Integrum speakers (104 dB) and get the most satisfying sound I ever had. The amp uses signal tubes only and pure class A with amazing results. Teresonic's on the other hand, with no-crossover design create a dynamic range that has to be heard to be believed. Yes, high efficiency speakers will take you places were others can't even think of.
I tried Zu's and though they were good, they weren't as good as Vandy's.
Maggie's with a Zero Autoformer might work with the M-60-Once again, Ralph would know. He does speak highly of Sound Lab speakers.
Bob
  If you are worried about your listening room, call Spatial Audio. I do not have an ideal room, needed high eff. speakers for a First Watt J2. I went from Tekton (which were very good speakers) to M3 Turbo S, then upgraded to the Triode Masters. Very satisfied, they are worth a phone call.
@pstoresHave you considered Zu? They are in Utah.
I have a pair of the Soul Superfly, very efficient like all of their speakers.
I run them with various low powered valve amps, even a little 2.5W Miniwatt that can drive them to uncomfortably loud noise levels.
They also pair well with various SS amps and at the moment I have mine connected to a Peachtree iNova which sounds wonderful.
Zu even have a loaner system which makes them easy to try out in your own home.Good luck with the search!

Thank you for the recommendation, @ohlala .

I really like Ralph’s amps and pre-amps (I have an UltraViolet too), so just about all of my speaker designs have his amps in mind. Specifically I usually shoot for compatibility with the S-30, on the theory that if a speaker works well with the S-30 and with solid state, it’ll work well with everything in between (which would include the M-60). Which is another way of saying that I pay a lot of attention to the impedance curve, and make it possible to adjust low-end tuning to take amplifier output impedance into account.

Given that your room is open on two sides, imo we’d want a radiation pattern that has relatively little room interaction, at least from early sidewall reflections. Assuming one of those openings is on a side wall, you’ll have zero reflections from that side but a normal amount of early reflections from the other side wall, and the imbalance can skew the imaging. But if the speakers have a fairly narrow radiation pattern to begin with, along with strong toe-in, we can minimize the early sidewall reflections off of that one wall and therefore reduce the discrepancy.

Two of the walls having big openings implies that we may need a lot of bass energy, as those two big openings may act like very effective bass traps. Or they may not. Anyway imo a fair amount of adjustability in the bottom couple of octaves is probably desirable.

Finally those big openings mean that the music will flow into the adjoining rooms, and it might be nice if it sounded good in those adjoining rooms as well. This implies that we want the radiation pattern to be fairly uniform so that the reverberant field has a natural-sounding tonal balance. This is something a good horn system does well, resulting in good sound "in the next room", where we have no line-of-sight to the speakers so all we can hear is reverberant sound.

Ohlala mentioned that my designs can have some of the characteristics of dipoles.  I was a SoundLab dealer for many years.  I like the natural timbre and deep, enveloping soundstage you get from good dipoles positioned far enough out into the room, but such positioning isn't always practical.   So I have a technique for achieving that sort of presentation which does not require the speakers be pulled way out into the room. 

Obviously my biases are showing through in this post, so take it with as many grains of salt as needed, and best of luck to you in your quest.

Duke

dealer/manufacturer

@firstnot none of those speakers are what most would call, efficient speakers. 
Owning a pair of Salk Song 3 BeAT's that are driven by a Primaluna Dialogue HP integrated,  in a similar sized room, I can attest they sound marvelous and are plenty efficient.

However, pstores specifically was looking at horns below 10k being driven by a less powerful tube amp. That is why I suggested the Spatial X2, however they are not true horn with the AMT driver, but these open baffle speakers are and within budget

Pure Audio Project Trio 15 Horn 1
$8k
96 db 

https://www.pureaudioproject.com/trio15-horn-open-baffle-speakers/
Klipsch Heresy IIIs...a steal at around 1500 bucks new (look around), not sure anything comes close...built like a tank, unique slanted fat little things that sound beautiful, and 99db efficiency works with anything.
Unless the speakers are up against the wall and your seating against the opposite wall (not ideal, both your seating and the speakers should be at least 2ft off the walls, use a sofa table or something to take up space if you want). 
 
Ideally wattage should double with the halting of impedance, so even though your amp is 60W into 8ohm, it is 45W into 4ohm (unless this is a typo), meaning if you use a 4ohm speaker, you are efficiently feeing it <25W if it were an 8ohm speaker. 
 
At 10ft away and wanting 100dB peaks, you would need 91dB or higher efficency. 
 
The Noesis 215RT would be excellent at <$7500 shipped, not sure if the looks are for you though. 
 
Salk also custom makes speakers, so you could go that route, it would just take a long time as they would have to find the suitable drivers, test that it would work well, fine tune it, etc.
Those Salk 3’s are beautiful, but also 88db - not the most efficient.

Don’t lose sight of Decware, either:
http://www.decware.com/newsite/HR1.html
Terrific.  Absent noise issues, the M-60 is a great amp for almost any reasonable loudspeaker.  I was just concerned about the OP's situation because of his plans to utilize high efficiency speakers.  


@larryi ,
My Atma amps have no hum whatsoever. If you did have hum, perhaps you had grounding issue. In any case, I would have called Ralph to get to the bottom of the issue.
Bob
I would recommend the SALK Song3 Encore's priced at $6,000.  Jim Salk sells direct and can afford to use the best drivers.  Incredible sound.  They sounded better than a pair of $60,000 speakers I heard at the Rocky Mountain Audio Fest this past October.
Recently, at the Capital Audiofest, outside of Washington DC, I heard some remarkable, very high efficiency speakers made by Charney Audio.  The system I heard cost $17,000, but, they do make cheaper as well as more expensive systems.  They, like many high efficiency systems, sound particularly good at lower volume levels and would be very good in a small room (the room at the show was small).  I liked the Charney speakers I heard at the show enough to be considering them even though they cost a fraction of what I currently run.

I have also heard, and liked, Rethm speakers and the Tekton speakers that are also reasonably efficient.

Do you have any hum or other noise issues with the M-60?  Every one of them that I heard had a very slight hum.  This hum would be more pronounced with high efficiency speakers, particularly if you will be sitting close to the speakers in a small room.  That would be another issue to consider when going with higher efficiency.

  
Magico A3s, Focal Kanta 2s, Joseph Audio, Harbeth 30.2, Spendor D9.

Your head will be spinning but OH what a ride!!!
I am doing a similar search. Take a look at Audio Note AN-E. Large range of prices. Maybe problematic for your room due to the fact that they prefer to be placed in corners.
Ihasa, OTL amps are High Current so different from regular tube amps. I could Monostrap my Atma-Spheres and get about 180 watts into a stable 2 ohm load and have High Current. Tubes would last as they’d never be stressed. Think that would be awesome... but gets pricey even buying used.... okay back to reality.... lol... 
 
Treos maybe tough to drive with the M60’s. 85 dB at 6 ohms. Also, at that price with the subs. I am closing in on the Quattro CT.... 87 DB at 8 ohm... which is the treo with the Subs built in... Ummmmm, so many decisions... 

Wow. Maggies, Devores. Spatials... you can't go wrong with any of them! Still, something not too large.

Maybe the Spatial M3 TriodeMaster - 93db @12 ohms.
I have my Vandy Treo's at near mid-room (between LR and DR 12x24x8).
I have excellent soundstage and reproduction with a pair of 2wq subs.
I owned the 3a sigs and went up to the Treo's. No comparison, everything is much more coherent/ seamless.
I also own Ralph's MA-1's/MP-3, as well as Ayre MX-R's.
Both amps are beyond what I thought I could imagine/afford.
I would ask Ralph is the M-60's could power Treo's-If you got the 2wq subs, I think it might work. And, you'd be 85-90% close to a Quatro.
Bob
I have Maggies and Love rhem, but I might look at high efficiency speakers in a do over.

I would love to try a tube amp as I have a tube pre amp.  However, Maggies require Lots of current and that removed the tube amps from consideration at my budget point.

Enjoy the journey and ket us know where you end up.
These will give me something’s to look at. The NSMT’s I already drew a line through. As with the KLipsch. Since I had owned most of the Classics from Chorus II through the Khorns. I’ll do alittle digging on the rest. Appreciate the responses. I am also considering Audio Classic Loudspeakers. Except one from there low end. 
Daedalus speakers are 96-97 db efficient
very dynamic, tonally balanced and engaging

lou Hunkley crafts solid wood speakers with a vibrant  realism
You might want to take a look at these. They check off all of your boxes, and have received many great reviews.

Spatial Audio X2

http://www.spatialaudio.us/pagex2/
Audiokinesis speakers are terrific and are commonly married to Atma-Sphere. Duke LeJeune has great taste in sound. They are front loaded horn hybrids but strike me as a blend of a wave guide, although I may stating this out of turn. Fatigue free sound with option of an even sound distribution like dipoles. 


While I love my current (and I hope final) system, If I had it to do over, I would go with high efficiency speakers (100 db+). They give you so many options in amplification. I'd love to try the Pass Labs XA25, 300B amps, etc.. And they still let you use high-power amps. Very versatile. 
With that small of a space you might want to make sure whatever you get will work well close to the wall behind. That eliminates anything that fires or ports to the rear. So no dipoles or rear ported.

Larsen supposedly makes a speaker or two intended to be close to the wall. A number of friends heard them last year at a show and they were the highlight (Capital Audio Fest). I normally wouldn't mention something like this, but when ten people rave about the same item at a show, that's pretty interesting and rare. I've never heard them, but could be worth looking into. 

There's a used pair of Vandy 5 from a legit seller listed here for $4k, pretty tunable for the room and very good speaker overall. Visuals on the pair aren't ideal, so buy 'em and dim the lights ;-)  Cheers,
Spencer
Being open on two sides, rather than a square(13.5 X 13.5), is an acoustic benefit. I used Maggies(SMGa/MG12/1.7i), for decades, in an actively bi-amped systems, with tubes on top. Recently, I purchased a pair of Emerald Physics’ systems, and won’t be looking back. Much more efficient, with wonderful imaging, immediacy and tonality. The other choice/option was finding SS main amps(more juice), that could match the transparency and sound stage depth(etc), that my modded Cary’s provide. That would have been too expensive. Make it easier, on your excellent electronics. Then again everyone doesn’t enjoy pretending they’re at the original recording venue and attendant SPLs(I like to feel the music).
Hey pstores,

Take a look at the thread entitled, "if you love SET ampilifiers, boy to I have a speaker for you".  The NSMT Model 50, which is way under your budget, is terrific for the reasons stated on that thread.