Genesis g 928 brochure

Page 1

G-928 I t combines fi rst- rate musicality and exceptional delicacy with a bottom- end solidity and power that was fully up to the job of reproduc- ing todays dynamic soundtracks. Transient impact was extraordi- nary…bass extension was outstanding. Robert Harley, The Perfect Vision magazine Visit www.genesisloudspeakers.com to download a complete copy of this review. T he Genesis G-928 Servo-Subwoofer was created using several refi ned technolo- gies - servo-control, metal cone drivers and effi cient, hyper-linear switching (Class D) am- plifi cation - which makes it able to accurate- ly and instantaneously reproduce the subtle- ties of a bowed double bass or the shuddering footfalls of an angry T-Rex. The G-928 transducers. In contrast to the comparatively heavy or lossy materials used in almost all other woofer cones, the G-928s dual 12-inch driv- ers are made of lightweight yet inherently stiff metal. Thanks in part to massive magnet structures and long-throw voice coil assem- blies, these precisely contoured cones are free of the transient-blurring artifacts imposed by lesser materials. With greater radiating area than even a 15-inch transducer, the dual 12- inch cones respond instantly to input signals to reveal details often obscured by heavier, less responsive designs. Also, they can deliver surprisingly substantial volume levels for their modest size. True Servo Control. Inertia is the enemy of accurate low fre- quency reproduction. The woofer must start instantly- and stop suddenly. However, its inertia makes it sluggish, resulting in over- hang, bloat, lack of tautness and a blurring of dynamic impact.Rather than simply send the woofer pulses of power and hope for the best, the solution is to carefully monitor the woofers movement and make instantaneous power corrections to get it up to speed and stop it on a dime. Very few loudspeakers use servo drive, ei- ther because most designers think that it is too diffi cult to design, too expensive, or because of the extraordinary demands a servo system makes on the amplifi er and woofers. However, Arnie Nudell, Genesis Chief Scientist, is more than comfortable with servo control: he designed the servo system in the legendary Infi nity Servo Statik One back in 1968 - and has continued to refi ne the design using new materials and technologies. The G-928 is the latest iteration of his research. A precision accelerometer on the woofer continuously monitors motion and sends a signal to high-speed circuitry that compares actual cone movement to the input sig- nal. The comparison circuit instantly identifi es any deviation from ideal response. Then, in real time, it adds a corrective signal to compensate for any deviation from the input signal even when they in- clude complex, rapidly evolving musical bass lines or cinema special effects. With this constant-feedback servo control, the transducers are essentially massless and anechoical- ly fl at. While typical non-servo woofer systems have distortion levels that exceed 10% at even moderate levels, the G-928 servo bass system reduces distor- tion to below one percent at almost any output level. In short, the G-928 guarantees earth-shaking bass coupled with stunning articulation. The G-928 power amplifi er. The servo system places extraordinary demands on the amplifi er since the system uses enormous amounts of current to precisely control the woofer. The best amplifi er for this application is a Class-D switching amplifi er with its dynamically increased effi ciency, especially at extreme low frequencies. The G-928s proprietary and ultra-effi cient Class D, discrete MOSFET switching amplifi er is a prime example of intelligent power application in the service of sonic subtlety. With output capability up to a full kilowatt of peak power, the G-928s Class D design provides extraordinary control and excep- tional thermal stability even when playing the most demanding sources continuously at high volume. It is remarkably cool running, too, thanks to the designs inherent 90% effi ciency (versus as low as 50% for traditional Class A/B amplifi ers).