|Usher Debuts The Be-718 Tiny Dancers Featuring Beryllium Tweeters|
|Home Theater News Bookshelf-Monitor Loudspeakers News|
|Written by AVRev.com|
|Tuesday, 08 May 2007|
Usher Audio speakers and electronics are built for the experienced listener who won't compromise on sound quality even at moderate prices. The stand-mounted Be-718s--the Tiny Dancers--features Usher’s 1.5-inch Be beryllium dome tweeters and carbon-impregnated paper-cone midbass drivers.
The Be-718s fills even medium-large rooms with impressive musical dynamics; the integration, speed and clarity of its drivers are exceptional. Expansive, quick upper frequencies are redolent with harmonics for rendering female vocals or the quick shimmer of brass.
Our Be tweeters uncover low-level details usually lost in the noise floor of less resolving speakers. Dr. Joseph D’Appolito serves as Usher’s technical consultant, providing guidance in crossover design. The result is powerful, transparent sound from well-crafted and finished cabinets at very affordable real-world prices.
The Be-718s, like all Usher speakers, are produced with skill and pride in an ultra-modern factory in Taiwan with great attention to manufacturing efficiency and productivity, turning out speaker systems incorporating advanced technologies like the Be beryllium midrange drivers found in the floorstanding Dancer Be-10 and Be-20.
Usher has been producing speakers in Taiwan for more than thirty years, and makes a number of specialized in-house drivers featuring Be beryllium ceramic diaphragms. These are created by heating beryllium formers to greater than 700 degrees, transforming them into brittle but extremely high-strength beryllium oxide. This ceramic’s enormous strength-to-weight ratio pushes the Be dome tweeter's transient response to an extraordinary level while minimizing distortion.
The Be tweeters&Mac226; upper-frequency response is focused and dynamic. Some manufacturers run their beryllium tweeters above 30kHz because they can, but research with the standard-setting Klippel R&D System that dynamically measures non-linear motion clearly shows that running beryllium tweeters out to almost 40kHz causes break-up distortion. Usher’s Be tweeter operates up to 30kHz eliminating the dual resonance points most beryllium tweeters are saddled with.
As a cost-cutting measure some manufacturers specify a voice coil that’s smaller than the dome it drives, but that creates resonance and distortion. Usher uses a full 1.5-inch voice coil driving the diaphragm close to its outer edge for better control, higher velocity, and power without break-up distortion.
Symme-Motion Technology Explained
Usher’s Symme-Motion technology--applied to all Usher drivers--symmetrically locates the voice coil within each driver’s magnetic field “linearizing” the motor’s movements. That is to say, when applying positive voltage to the cone moving it outwards, it moves backward in an exactly symmetrical way when presented with the same negative voltage. Symme-Motion ensures the voice coil remains exactly centered within the magnetic field.
Usher ensures optimal symmetry and linearity as individual drivers and paired speakers are closely toleranced to within 0.2dB sensitivity for stereo pairs.
Another element of Usher’s driver designs are the selection of materials and the design of the supporting basket or spider. Without careful engineering the baskets may act like springs and cause non-linearities in the output. Even the driver surrounds are designed to absorb vibrations that might otherwise reflect back into the cone resulting in further non-linearities.
Source: Press Release