SET friendly speakers w/ slam?

Seems to me to get slam, you need some powered subwoofers (either separate or built-in as offered in the speakers mentioned above).

Hmmm, I wouldn't associate subwoofers with "slam" necessarily. Visceral, absolutely yes! But I'd put "slam" into a region just above where subs do their deep, dark, rumble'yer'roots thing. I'd associate it more with detailed tight, fast bass that's moving lots of air fast. Subs are more about the bass you feel in your bones and in your guts. Maybe its a matter of semantics and my (mis)understanding the terms. Regardless, I'd check out Coincident's offerings as well. Silverline's full-range offerings hover around 92 db so are just at the low end of set-friendly, and they're superb speakers IMO.

Marco

Hey Grant - I'm guessing from his current choice of speakers, that the poster might be considering the more substantially endowed Silveline offerings (Grandeur II, LaFolia II). On my Sonatina's, though I'd give the nod to SS amps I've tried (Odyssey dual mono, BelCanto Ref1000) as far as "slam" is concerned. I'd agree with you that I would not necessarily associate SET as a "slam optimizer". If you're really way into "slam" I'd pick a different delivery of power (push/pull, OTL or SS all would likely be a better choice). But if you are looking for ways to optimize slam with SET (assuming you consider the strengths of that form of amplification as more of a priority) there are certainly some speakers that are better than others at doing just that.

Regarding the Emerald Physics suggestion; I was impressed with those speakers at RMAF, but I thought they required substantial current in spite of their high efficiency. I seem to recall reading from several sources that tubes were not suggested, and if they were used that lateral biamping was recommended. The tube amps they were using at the show were push/pull and pretty punchy. I heard them with the Bel Canto Ref1000 and they sounded great. This is the first I've ever heard anyone suggesting to use SET amps with them.

Research these:
Classic Audio Reproductions. I do know they have a very tube friendly impedance curve, and they are very sensitive (over 100dB).

I think those are the horns Ralph shared the room with at RMAF... If so, very impressive large-scale, huge soundstage with his amps. They certainly have a 'large' physical presence in the room yet they disappear as the source of the sounds.