I've got the Super 3 XRS's and, as you may have read on some earlier posts, have had, like all of the great loves of my life, some ups and some downs! Louis himself says it best when he says that the XRS's are an unforgiving speaker, and if you read much about the single driver philosophy you know that that directness is exactly what many listeners love about single drivers: no crossovers to color the source, no "engineering" to make the source sound better at the speaker, something very pure, direct and present.
We all remember when it was fine to throw a cruddily mastered Boston lp onto our Technics turntables and cranking up the pot on our Circuit City JVC and listening to our Cerwin Vegas thump and bump and thinking it just didn't get any better. Then we had the opportunity to play our same BOston record on someone else's hi fi system and we heard the record differently. Then we played the same record on a SUPER system and realized, sadly perhaps, that the record sounded, well, like crap, not because the system was bad but because it was so good: it emphasized the poor commercial mastering of the lp, something that had been hidden or veiled during our earlier listening sessions on our Tech/JVC/CV combo.
The XRS's, and all single driver speakers I suspect, are the end result of many listeners' attempts to strip all the muck away and attain a least the illusion of the purest sound available. It's a valid philosophy, imho, and is why I'm both keeping my XRS's after entertaining the idea of selling them and also urging you to research the 'single driver theory' more before purchasing some. I'm pretty sure we all know the danger of recommending a piece of hi fi gear unconditionally and the XRS's haven't changed my mind about this reflex of caution. They are beautiful, killer speakers that will engage your heart and your mind and really make you think long and hard about what it means to be so deeply enthralled by various performances of recorded music. They are also brutally direct in some instances and, again imho, in no way should they be called "warm". I recently had the chance to listen to some very highly regarded Spendors on my system in addition to some brand new Quad 22ls and both sounded quite a bit "warmer" that my XRS's, but also muddy, confused and bloated after my lean and mean XRS's.
I recognized then and their that I'd gone on a hi fi diet and wasn't about to dive back into the overly sweet and rich land of crossovered speakers.
BTW, some well-recorded acoustic music sounds so bloody good on my XRS's that it's creepy.
Also, these guys' blog is pretty informative: http://singledriver.blogspot.com/
Food for thought.