Rich,
Yikes, yet another thread that hasn't sent me any notifications -- sorry, never saw your reply.
To answer the question about high frequencies, yes, I do think the better single driver speakers can reach pretty high frequencies -- some of the Fostex drivers claim 3 dB down points of 23 KHz, but I don't think that's the whole picture. At those frequencies, especially the larger the cone, you are necessarily getting a lot of break-up modes, which, if your hearing is sensitive enough, can certainly grate on you. Even if they don't do that so much, the break-up modes do contribute to some loss of transparency. At least this is my perception from my experiences -- the high end was never lacking in real extension, but did tend to get grainy and harsh, and just nowhere near as transparent or "effortless" as say the round ribbon tweets on the Adagios. I am pretty sensitive to tweeter nasties, but the Adagio tweeter is among the best I've heard so far, only losing to the diamond tweeter in the Kharmas and the Acapella ion tweeters, and we're talking about a huge price differential there.
I think Mike pretty much nails it with his comments, and I don't know that I have anything more useful to add to his statements, except that hybrids seem to be a relatively cost-effective compromise.
No speaker is everything to everybody, and I suppose for me, the real thing is to have a fairly even and smoothe response from top to bottom, with decent, but not ultimate extension at both ends, and as transparent as I can possibly afford. So far the SD systems I've owned and listened to didn't have nearly as much transparency as most would have had me believe I would experience. For me, the real acid test is the clarity of voices, and while they have been good, to very good, I was utterly amazed the other night when I played an Eva Cassidy CD on my system with my still very green tube amp, and for the first time ever, could effortlessly understand every single word she sang, without even trying to listen for it. No SD speaker I've had, no matter what amplification/source could ever do that.
I have obviously not heard the megabuck SD speakers that Dick Olsher talked about, but at that price tag they are in the same league as the Reps, and some of the more exotic Phy and field-coil offerings from Western Europe -- and sure, I'd love to be able to hear all of them, but that's not going to happen, which is to say that my comments are based on the very limited selection of drivers I have heard in my house, which include a couple of Fostex (priced at $85 and $60 respectively) and the Visaton B-200 ($135), and those which I've heard at shows -- some Lowthers, and the AER Mk II. and Louis's hemp drivers (which sound pretty damned good to me, but still not everything I want/need in a speaker.)
Everything in audio is a compromise, right? Well, the SD driver is no different, and as good as the engineering has advanced, you're still dealing with some laws of physics that are pretty hard to defy.
For my taste, right now I'm giving a lot of thought to a crossoverless 2-way with active filtering before the amplifiers with possibly a chip amp on the bottom end and a small tube amp for the high end -- not at all unlike what Mike has going with the Def Pros, but on a much smaller, more modest scale, and a more conventional mid/bass - tweeter driver complement.
Bottom line is that I think SD speakers can do a lot of things right, but they just don't mesh well with my particular tastes/needs, or another way to say it is that they, so far, haven't been the right set of compromises for me.
All done now
-- Jim
