I can't answer your question directly but I can say that I couldn't be happier with my Classic 4's.
NHT is still alive. They have reorganized and are an internet dealer yet still have a number of brick and mortar retailers as well. They just added a third partner Frank Sadowski whose forte is consumer electronics e-commerce.
I for one wish them well. I own the Classic 3's and think they are fantastic for the money. $700 new.
Late to the party, but since other people read these forums besides the OP, I'll answer.
I've owned both, still own both, and dry up with the same amp and preamp, the Classic 4s obliterate the 2.5I's. Similar house sounds, with an up tilted tonal balance, but the classics disappear better, have more extended highs, deeper lows, better soundstaging, and sound more refined.
Hey Background, thanks for your post. I've always wondered how these two compared. I had the 2.5is years ago, then sold them only to re-buy another used pair about 3 years ago for $250.00. I've never heard the 4s (i had the 3s too), but have always been curious. i've noticed they have gone down in price tremendously on the used market. i might just go for it!!
I had an absolutely gorgeous pair of Mahogony 2.5's a few years back and as much as I wanted to love them I never got the sense that the bass was truly integrated with the mid's and highs. It always seemed detached and rubbery sounding to me (if thats a word) and ultimately I moved them. Even the wife liked the looks of them and she was quite dissapointed when I moved my NLA's back in but what can you do, they gotta bring the tunes...
Had the same problem with the 2.5i (jealous of that mahogony finish you had Polarin!) The Classic 4's (and 3's I have in my bedroom), are the first NHT speakers I'd recommend to anyone, not just people who like NHT.
People would hear my 2.5i's, and think about buying them, and I'd warn them off. They really needed the right amp, ancillaries, and room to work. The Classic 4's need power, but they're not as fussy. Heard them sing with an Arcam a38, and with my McCormack DNA1, even with a Pioneer sc61 I use when it's just too hot, and I don't feel like running my McCormack space heater. Couldn't run 2.5's off a receiver like that. (well, you could, but they'd sound like hell)
They're great speakers. My only audio friend has Thiel 2.4's, and while we're both too prideful to ever admit that "your speakers are better", we both get tremendous enjoyment out of taking over one another's systems when one visits the other.
I've always loved the mahogany finish on that line. I thought they were stunning, though i never bought a single nht pair in that finish, that whole line was really fun to play with. I actually had more fun with the 2.5is than the 3.3s. the only reason why I sold the 3.3s was because I got an incredible deal on some genesis speakers. i've always heard that they all needed some balls to be appreciated. I recently sold my tubes and bought a class d amp. just for shits and giggles, im going to try out the 2.5is with that amp. I hope I don't blow them, or worse.
Background, you are the man! I don't mean to hi-jack the thread, but it is relative to the original post. I hooked up the 2.5is to the d-sonic. those little old suckers have never sounded better...ever!!!. they can take a lot!!! I had to turn up the volume way up to really hear them the way they were intended. I have a newly found respect for those old things.. if only i'd kept the 3.3s. its also amazing what high power class d amps can do. but now I want the 4s, since you've said they're much, much better.
in the meantime, rock on everybody! thanks to everyone, especially background.
Got a pair of 2.5i recently in mahogany finish. Beautiful speakers. Power them with a pair of 40w vintage tube amps. Big, beautiful sound, but those cheap clips on driver connections must go to realize the true sound of this design.
Not power hungry if you are using tubes. A 10Wter will give you very sweet sound too. Bass is tuneful and in proportion to the rest of the system. Very satisfied guy I am after all the Soundlab, ML, Mag, Apogee, Infinity RS, and Legacy focus....