Revel's newest speaker, the Performa F228Be, has been in the works for a few years, with a lot of excitement brewing in enthusiast circles. Prototypes of the speaker were displayed at audio shows for a couple of years and many described it as a Revel F208 with a Beryllium tweeter. I had a pair of F208s in my system for a while during my review of the Mark Levinson No. 585, so I was familiar with them.�The imaging and dynamic response of the F208s were very good, and my limited listening experiences with the Beryllium driver prototypes was positive, so when I had a chance to spend time with the new F228Be, I jumped at it.
I have to admit, though, to being a little surprised when I saw that the F228Be was priced at $5,000 each, double the price of the F208. This seemed like a big jump in price if the only change from the F208 was the addition of the Beryllium tweeter. I spoke with Kevin Voecks, the Acoustic Technologies Manager at Harman, and he was not surprised when I queried him about this misperception that the F228Be was basically a F208 with a new tweeter. Kevin patiently explained the myriad of differences between the F208 and F228Be. In short, the only thing that is the same is the cabinet.
I surmise that had Revel changed the cabinet, the F228Bes would likely end up costing nearly as much as the $16,000/pair Salon2. The F208 and F228Be cabinets may be a bit staid in design, but are very well engineered. The flat front panel has the four drivers flush-mounted above a front-firing port. The drivers and port can be hidden by a magnetically attached grille, but the white drivers in their black surrounds have a clean, modern look that some may wish to display.
The F228Be can be had in your choice of choice of four high-gloss finishes: Black, White, Walnut, or Metallic Silver. My review samples were finished in an attractive polished Walnut with a metallic black curved top panel and a black plinth that extends slightly from the body of the cabinets. The cabinets have curved sidewalls and resemble the blunt bow of ship when viewed from above. The curved shape and internal bracing make for a solid, inert cabinet that only emitted a dull thud no matter where I knocked my knuckles on it.
The three-way, 46.6-inch tall, 13.5-inch wide, and 14.8-inch deep speakers weigh in at 82 pounds apiece and contain a lot more technology than the Beryllium tweeter that has dominated the pre-release chatter. However, Beryllium tweeters are still pretty sexy in the world of speaker design, so I will start there and work my way down. The one-inch beryllium tweeter features large, 85mm dual ceramic magnets as part of its powerful motor structure.
In my discussion with Voecks, I recalled that the much more expensive Studio2 and Salon2 also had Beryllium drivers and asked if the F228Be's tweeters came from those models. I was informed that the Beryllium tweeters are an all new design, which leads one to ask: why use Beryllium if you have a clean sheet of paper? According to the Revel marketing materials, Beryllium "is a rare earth metal that is renowned for its remarkable physical properties that make it the ideal material for a high-frequency transducer. Compared to aluminum and titanium tweeter diaphragms, Beryllium offers 4.5 times the stiffness and three times more damping, and does so at only half of the weight." In short, it is stronger and lighter, and will exhibit less ringing than aluminum or titanium.
During some of the recent trade shows, I asked the Revel personnel about Diamond as a diaphragm material and they explained design choice reasons in favor of Beryllium. Diamond dome tweeters have a higher velocity of sound than Beryllium, which impacts the material's breakup frequency, but Beryllium is still beyond 50 kHz, so that should not be a problem in this application. Beryllium's lower density, as compared to Diamond and most other tweeter materials, minimizes density and distortion. Revel also cites "Poisson's Ratio." The lower the ratio, the better a material's elasticity is suited for audio. Beryllium's Poisson's Ration is .08 compared to .31 for Diamond and .33 for Aluminum.
Having spoken with numerous speaker designers, I have come to the conclusion that either of these materials can be used to make a great speaker, but there is much more than the diaphragm material that determines whether the tweeter will sound great. And much more than a great tweeter is needed to make a great speaker. In the case of the F228Be, the Beryllium tweeter is combined with a fifth-generation ceramic-coated, cast-aluminum Acoustic Lens waveguide engineered to integrate the tweeter's directivity with the directivity of the midrange driver. The 5.25-inch midrange driver and the two eight-inch woofers have Revel's Deep Ceramic Composite ("DCC") diaphragm, which is all new for the PerformaBe series of speakers.
Revel describes DCC as "a plasma electrolytic oxidation process that uses a plasma discharge to create a coarse ceramic coating on both sides of the aluminum core. The deep ceramic layers sandwiching the aluminum core provide constrained layer damping that push cone breakup modes outside of the passband allowing the driver to maintain ideal pistonic motion throughout its range."�The DCC cones are coupled with an improved motor structure for greater efficiency, dynamic range, and power handling, with reduced distortion and compression. Last but not least, the crossovers in the PerformaBe series are high-order crossovers that utilize all film capacitors and air core inductors in the midrange and tweeter circuits.��
I positioned the F228Bes in my room with the front baffle three feet from front wall and approximately eight feet apart. I experimented with the amount of toe in, and with the F228Bes' wide dispersion I ended up with them pointing to a spot just in front of my listening position. Once I had the position figured out, I installed IsoAcoustics' GAIA II feet.
The F228Bes were evaluated in both my reference stereo system as well as in a multichannel configuration. Starting with the stereo system, I used a single pair of Kimber Select speaker cables with Kimber Select jumpers to connect to a Halcro dm38 being driven by a McIntosh C500 preamplifier. A PS Audio DirectStream DAC and Network�player served up the music from either audio files stored on my NAS or discs played on my Oppo BDP-95.
I also tried the F228Bes in a multichannel setup with a Marantz AV8805 AV Preamplifier and Krell TAS Amplifier�driving the F228Bes as they flanked a Revel Performa3 C208 center channel. There is currently a pair of small, stand-mounted speakers in the PerformaBe lineup, the M126Be, but there is no center channel as of yet, so the C208 had to suffice.
Click over to Page Two for Performance, The Downside, Comparison & Competition, and Conclusion...