No other speaker component gets as much attention from innovators and fiddlers as the tweeter. It’s easy to understand why: your ears can forgive some weaknesses in the bass or even the midrange, but if you get the highs wrong, your product is unlistenable.
Ah, but when you get the top end right – extended, yet smooth, detailed rather than clinical, sparkling but not brash – the audio world will come running to your door. As a result, mid- and low-frequency drivers tend to be pretty much like the grocery clerk says, “paper or plastic?” But tweeters — those are left to the mad scientists who laugh maniacally while plying their trade.
Aluminum? “Sure.” Silk? “Bring it here.” Beryllium copper? “Even better.” How about diamonds, master? “Now you’re talking.” What about electrostatic panels or ribbons? (Crazy laughter echoes through the lab.) “Yes, yes. All of humanity will know my name!”
I have no idea if the folks at eFicion are insane, but I’m betting they did spend their fair share of time sequestered away in R&D, determined to solve the elusive perfect tweeter problem. The result they came up with for their F300 ($16,900) a pair) was to use both a large, front-firing, air-motion transformer and a rear-firing ribbon. (Cue evil laughter in background.)
Both tweeters are built into a detachable head unit that also houses a 6.5-inch carbon-fiber midrange. That sits on top of a taller, wider cabinet that holds a 12-inch carbon-fiber woofer. Frequency response is quoted at 25-40kHz, and sensitivity is 90dB. Crossover frequencies are 1,300Hz and 110Hz.
The pair I saw at CAS 2014 was finished in a lovely piano black. The speakers were being driven by a Plinius SA-103 amplifier ($10,150), Exemplar Audio SE preamp ($4,250) and Exemplar-modified Oppo disc player ($4,500).
OK, there can be crazy-good and crazy-bad. Which was the F300? Definitely the former.
The sound through the eFicion speakers was smooth and refined. The top end was airy and lightning-quick on transients. There was no lag in the midrange and bass, however, as sometimes can happen when ribbons are paired with cones. The bass, in particular was tight, nimble and actually seemed to have plenty of output all the way down to the lower end of its rating. This gave the F300s a solidity and foundation matched at the show only by Wilson’s Sasha 2, which also uses a separate lower-frequency cabinet.
While some other speakers on the market use various applications of ribbon technology, I think eFicion’s masterstroke (or proof of true insanity?) is the addition of a rear-firing super tweeter. This seemed to allow the speakers to throw an exceptionally deep and wide soundstage. Designers often avoid this strategy for fear of creating unwanted reflections, but in the F300’s case I heard no smearing or congestion. Instead, there just was an effortless ease to their presentation that was addictive.
There’s a thin line between genius and insanity. The eFicion F300s are speakers I easily could go crazy over.
[editor’s note: In point of fact, we did go a bit crazy over them!]