Eficion F300 Speaker Review

Introduction

My introduction to Eficion speakers happened by chance as it was one of the rooms that I was assigned to cover at the second annual California Audio Show last August. I had never heard of Eficion prior to the show and I certainly had no idea what they were all about. Of course, that changed rather quickly when I entered the room and came face to face with a pair of speakers that quite obviously were sporting a large air motion transformer driver! My audiophile geek senses tingled and interest level spiked upward as I recalled fondly the ESS AMT 1B that an older cousin of mine had in his system when I was a kid. He was the only audio buff in the family, so far as I knew, and those ESS speakers driven by a Marantz amplifier were a real treat for a young teen. Even to my uneducated ears, I knew that the air motion transformer had a sound that was more akin to the pricey exotic electrostatic speakers of the day than the garden variety classics of that era. Anyway, a quick introduction and chat with the Eficion designer Mr. Peigen Jiang, two visits and about thirty minutes of listening time and I knew I wanted to kick the tires on these babies in my listening room.

Eficion opened their doors in Seattle in 2007. There are three models in their line of speakers, two of which feature an air motion transformer driver: the diminutive F200, a 2-way vented box design that marries a pure aluminum foil ribbon tweeter with a 6.5” carbon fiber woofer with a shorting ring; the F250, a 3-way design that sports a 2.3” x 1” air motion transformer; and the top-of-the-line F300, that features a large 5 1/8” x 1 3/16” air motion transformer unit. The Eficion F300 speakers are the subject of this review.

Configuration and Set-up – Round 1

The Eficion F300 is actually a two-piece speaker design ala the Wilson Watt Puppy. In other words there’s a huge box enclosure for the woofer and a separate “hat” section, like a mini monitor, that sits atop the woofer box, and which handles the rest of the audio range. Therefore when the speakers arrived at my home it was in the form of four heavy palletized boxes. At some 160 lbs per side, these speakers are far from being considered svelte; add in the triple-carton packaging and you are looking at some serious shipping weight. As it turns out, there is a method to this unusual packaging. The triple cartons are indeed so sturdy and impenetrable that each box can actually be safely rolled up flights of stairs without harming the speaker. This made getting the F300’s up the stairs to my listening room a non-event.

The bottom two-third of the F300 is a single box enclosure housing a 12-inch woofer. The woofer is a non-woven carbon fiber sandwich cone unit that sports a prodigious 3-inch voice coil, damping coil, and a shorting ring to minimize any non-linearity present in the driver’s range of usage. The woofer enclosure is a 100+ lb beautiful black lacquered box cabinet. The woofer is crossed over at 110 Hz to a separate triangular black lacquered enclosure that houses a 6.5-inch midrange unit of similar construction to the woofer. This midrange operates to 1300 Hz which is where that huge air motion transformer takes over. A rear-firing 2-1/3” x 1/3” honeycomb structured aluminum ribbon completes the driver complement. The Eficion F300’s are fully bi-wire ready and come complete with a set of jumpers, and with pucks to mechanically separate the two speaker units per side. By the way, I rarely dedicate many words to aesthetics but in the case of the Eficion F300’s I am most compelled to comment. The heavy black lacquer finish on the speakers is truly extraordinary. In fact, I have seen few if any speakers with the fit and finish level that is as good as the Eficion F300’s.

Placing the F300’s in my room began with using the placement of my Martin Logan CLS electrostatics as the reference point. Through trial and error, I found that the optimal placement for imaging required that they be somewhat closer together than my CLS’ and that I move my listening chair a foot closer to the speakers. This created the optimal equilateral triangle that the manufacturer suggests and I confirmed as optimal for my room. This placement provided the best bass response, but the bass still seemed a bit disconnected with the rest of the sound spectrum. I decided to break the speakers in for a couple of weeks to ensure that the woofer’s suspension was sufficiently free in movement and not overly tight.

After a week, I realized that the sound was not changing with respect to the bass performance, and found the bass to have a somewhat wooliness to it. In fact, drum strikes sounded more like someone punching an over-stuffed pillow with their fist, so I reached out to Mr. Jiang who suggested that I change the amplifier because it was his opinion that the Eficion needed an amplifier capable of faster transients.

At first I switched to the Belles Power Modules Reference 350A v2 which was on hand for review. This proved to be instructional as the bass wooliness did indeed seem to diminish. However, it did not take very long for me to figure out that this might have been a result of the bass output in the lower reaches being diminished as well. So, that proved to be somewhat of a wasted effort. I then went to a much better known quantity to me, the Sunfire Signature Series II. After its normal warm up of 24 hours, it proved to give similar results as the Pass Labs X350.5 in the bass region. I decided that the amplifiers really were not the root cause and switched back to the Pass Labs X350.5 as it clearly was head and shoulders sonically superior to the other amplifiers I had on hand.

The troubleshooting of the problem had me perplexed and actually burned a good many hours over the span of a couple of weeks until I accidentally and quite literally stumbled over the problem, clutter. Over the course of the busy summer with so many things coming in for review, I had amassed a fair number of boxes, papers, displaced equipment, maybe 100 or so LP’s leaning here and there that were cluttering my listening room. These things didn’t affect the very directional CLS’s at all. However it was entirely a different story with the big box, wide dispersion, full-range Eficion F300’s. The Belles amplifier had been recalled by Dave Belles and after I packed it up and took it out of the room, I sat down for a listen fully expecting to be dealing with the never-ending issues of the problematic bass when all of a sudden I realized the problem was nearly gone and that a fog had indeed been lifted from the sound. After slamming myself over the head a few dozen times, I got to work in putting away records and cleaning up my room.