Efficient, affordable speakers for SETs?


Ever since I discovered the magic of SETs, I have been hooked and could never go back to “sand amps” or non SET tube amps. (Yes, I know they are dirty and colored but I love the soft clipping!) The seemingly endless problem has been finding speakers that not only function well with just a few watts of power but get the most out of the limited power and also sound real. Tried Lowthers in Medallion enclosures and some other enclosures but ultimately not very natural or satisfying. Realized that a two way speaker properly crossed over to a tweeter was best and found a speaker that was specifically designed to play with 8 300B watts. The Tetra 506s (worth checking out Tetraloudspeakers.com and the great musicians who use them!). Does anyone know other two way speakers designed to work well with SETs?
mglik
I’m using an Audion 300b 8 watt SET with Zu audio Soul Superfly’s and rarely need to turn the volume past 9 o’clock. The Zu’s are very efficient and have great dynamics and imaging. Very happy with this setup. It was quite a big step up from the Decware Torri Jr with Errx speakers I had previously. 
Thanks for the additional recommendations! The Klipschorns are the first high efficiency speaker I ever heard. Klipsch speakers are not my cup of tea. Pretty bright.
A lot of people swear by Zu speakers.
I only heard them once in an Audio industry friend’s house with his super expensive 2A3 amp and like digital front end. I wanted to run out of that room. Hard to imagine a higher end set up or a higher level industry guy. But I don’t want to rule out Zu speakers. It is just that their sound did not sit well. Surprised that no one mentioned Avant-garde. Over my price but the latest ones seem amazing. Even though MP4, the best YouTube I have heard in titled “Garrard 301 vs Studer”. A super system with AG second from the top pushed by a Nagra 300B.
The Charney Voxativ speakers are very interesting. Looks like the cheapest way to get into the fabulous Voxativs!
I have found that dB sensitivities are not nearly as important as the impedance curve. My Tetra 506s are 90dB but only dip down to 6 ohms staying mostly at a flat 8 ohms. And they were designed and voiced with 8 watts of 300B. Mine run very clear and unstressed.
I do imagine that they might put out more sound with more power but at my listening levels I hear a lot of information. Do feel I am hearing the unstressed character of the speakers. And I have realized, more than anything, that the character of the speaker is most vital. Assuming the right amp match, a speaker’s voice must be “digestible and delicious”. Is it perfect, who cares!

I agree with the high efficiency speakers.  I have a custom pair for my family room setup, which are driven by a 45/46 SET amp.  (Both are designed by Don Allen.)

The speakers use Eminence 15" coaxial drivers.
I toally back up rickraymond59. My Zu Soul Superflys really sing when running off a SET amp
As do my Klipschorns.
As do my KEF Transmission Lines but you’ll struggle to find a pair of them as they were home built.
I would think any Zu would work fine as would any vintage Klipsch.