Best SET Compatible Speakers, $4k-6k used

Twl is correct, the Lamhorns would be an excellent choice and can be had new for less than $6K with a choice of drivers. I have DX3 in mine. I would have gone with AER but they are 16 ohm only and my amp is 8. I think they come in 8 ohm now but I'm not sure. You will need a good sub to go full range, but most convential multi driver speakers need one too.

You won't get more than a few watts from a 45 amp so speaker choice is critical. I must respectfully disagree with the notion that SET systems limit your choices in music. I can only guess that these folks have never heard a fully realized system. If you can get back issues of Listener magazine there are many reviews of SET amps and compatible speakers.

TWL's recommendations are excellent, as usual. He is experienced and competent. I haven't heard the Lamhorns, but in this price range I like Rethm speakers, from India.

If you're willing to do a little custom cabinetry, then PHY of France makes some excellent high-efficiency 16-ohm drivers. I chose to become a dealer for PHY because their drivers deliver a bit warmer tonal balance and more satisfying bottom end (in my opinion) than other high-efficiency full-range drivers. The PHY's are actually crossoverless two-ways, with a high-quality coaxial piezo tweeter filling in the top octave. The recommended cabinets are quite simple, and even a large open baffle can be used.

If you want a multi-way speaker with a crossover, and if your heart is set on a 45 SET, then I'd suggest you try to find speakers with a rated impedance of 12 ohms or higher. The Classic Audio Reproductions T-5 is a possibility, though I've never seen a pair show up used.

Best of luck in your quest!

Duke

Both are rare finds these days, but the ESP Bodhran or the Brentworth Type III are each over 100 db and are world class loudspeakers in the right system/room.

Yes, I forgot about the Brentworth. I have heard them and they are very good. I assume they are still in business as their website is still active. Worth checking out.

If you don't want a horn/lowther colored sound, I would recommend Spendor SP100. Presents a very stable 8ohm load and has relatively high sensitivity (over 90db). Very musical and emotionally satisfying especially when driven by SET amps. And last I checked, $3300 brand new.