SET friendly speakers w/ slam?

Does'nt the question depend on output too? In simple terms, a 20+watt SET will give you more slam than an 8watt one. Tube choice is a factor too. Having had both, it is my impression that 845's are more even across the spectrum than 300B's say.
My Viva Solista, 22 watt 845 SET, really drives the 89db Acoustic Zen Adagios I use in a 20 by 20ft room. There is real, deep, tight base there. In fact, it sounds louder, with better grip, than a 180 watt SS amp I also use

Consider a custom loudspeaker you can have one designed for your budget room system and music tastes. So many new hi-eff transducers availible one can build hi-eff loudspeakers in so many ways. You could even DIY your own.

Emerald Physics mentioned many times will need more power due to the open baffle and are also an active bi-amped system meaning needs processors and 4 channels or more of amplification, so just using them on an outright S.E.T amp is probably more trouble than its worth in my opinion to recommend them realistically..

I do however agree with all the Zu recommendations if you want to keep it very simple..
Also the New Zu Definition as stated above is a great choice and now comes in a 30 ohm version and 101 db efficient which can be driven by anything.

A moderately to high sensitivity driver (fostex, lowther) in a well designed back loaded horn. Since going single driver all other speakers put me to sleep – and I mean that literally.

Regards
Paul

I get pretty good slamm out of the Reimer Teton's using my Lamm 18 watt SET's. The speakers are 95db and a flat 4 ohms. Reimer says you can go down to 8 watts with these speakers not sure how that may effect slamm though.