Revel Reveals All to Stereophile Scribes
Whether Revel has fulfilled Dr. Sydney Harman's mandate "to build the world's best loudspeakers" is open to debate, but there is no doubt that the startup has leveraged Harman's tremendous resources to great advantage. The company's loudspeakers have been very well received by reviewers and music lovers alike. At Revel, every aspect of speaker design is examined in the most minute and meticulous manner. Led by former Snell Acoustics designer Kevin Voecks, who is in charge of product R&D for Revel, and Revel's head of engineering Domenic Buonincontri, the Revel team records and quantifies everything that contributes to a speaker's performance—from panel resonances and complex cone motions to driver-enclosure interaction and crossover topology.
All the company's completed designs—from the $2000/pair Performa M-20 stand-mounted two-way speakers to the top-of-the-line Ultima Salon—are also evaluated in blind listening tests by Harman employees who are first tested for normal hearing and then trained to recognize typical response anomalies. Sean Olive, Harman's manager of subjective evaluation—the only such position in the industry, as far as he knows—uses programs developed in conjunction with audio pioneer and Harman VP Dr. Floyd Toole to teach his students how to recognize both broadband ("low Q") and narrowband ("high Q") peaks and dips in the playback frequency spectrum. In effect, Olive turns naïve listeners into trained listeners to ensure that he has experts on hand whenever needed for comparative rating of products not only from Revel, but from Harman's JBL and Infinity lines, as well as products from other companies.
With the exception of its Ultima-series tweeters, which are sourced from one of Denmark's most prestigious driver manufacturers, all Revel drivers are developed and manufactured in-house to some of the most stringent specifications in the industry. Woofer and midrange drivers feature high-compliance surrounds and spiders and parabolic aluminum, magnesium, or titanium cones for what the Revel team calls "pistonic," or uniform, ultra-low distortion motion throughout their frequency ranges. Even very-high-quality drivers of a type popular among high-end loudspeakers suffer from breakup modes, as we could see on a computer simulation developed by laser inteferometry measurements of cone motion. Stereophile editor and speaker-measurement guru John Atkinson was clearly covetous of some of Revel's research tools, which include several large anechoic chambers equipped with automated turntables and sweep generators for plotting speakers' on- and off-axis responses in the horizontal and vertical planes. Much of what Atkinson does by hand for a typical Stereophile loudspeaker review can be done automatically at Revel.
Even more impressive was a $500,000 computer-driven 3D modeler (in effect, a three-dimesional computer printer) that can turn a CAD drawing into a real prototype by laying down 1-mil thicknesses of plastic one layer at a time. We were shown woofer baskets, remote controls, and loudspeaker ports—all of which came out of the machine, whose potential appears to be limited only by the imagination of the person programming it.
Buonincontri told the assembled skeptics that his midrange drivers must have a frequency response within 1dB of the reference to pass quality control. Tweeter-midrange crossover networks are hand-trimmed by skilled technicians, who record every frequency response of every Revel driver against the engineering-standard devices that are kept under lock and key. The standards are measured daily to make sure production models do not deviate due to changes in temperature or humidity. The 1dB window makes the process of matching crossover to drivers time-consuming even for an experienced technician, sometimes taking 30 minutes or more per tweeter-midrange subassembly.
Revel doesn't supply dealers with generic replacement parts, due to the strict performance requirements. The company keeps both electronic and paper records of the parts used in every product, which customer-service people can refer to for supplying parts to customers. A blown tweeter, for example, can be shipped from Northridge only after techs have researched the original. The program ensures that no Revel product will suffer diminished performance because of a repair.
Dozens of skilled cabinetmakers, painters, finishers, and assemblers make sure that every item they complete not only gleams, but sounds perfect. Multiple coats of the hard automotive finishes used on Ultima-series speakers are baked and hand-sanded between every application in extremely clean surroundings. Revel craftsmen can produce six to eight pairs of the upper-tier models per day, Glazier told us. That seems a lot, given the labor-intensive nature of speaker building. Even so, the pace on the production line looked more relaxed than manic. We got the impression that everyone at Revel—from the marketing executives and engineering staff to the production workers—takes enormous pride in the company's products.
Next Week: Kevin Voecks discusses measurements and subjective evaluations, and we listen to some Revel speakers.