September 26, 2008 To commemorate Infinity Systems 40th year in the industry, the company has released the Prelude Forty speaker system. Featuring a slim profile and the companies proprietary Maximum Radiating Surface (MRS) flat panel driver technology, the Prelude Forty aims to satisfy audiophiles and the design conscious alike, with it’s looks and the most advanced engineering innovations Infinity have to offer.

The Prelude Forty’s styling is very distinctive. The sleek, elegant design is accentuated by the removable black grilles. The sound is smooth with accurate tonal balance both on and off axis, resulting in precise stereo imaging with a wide dynamic range.

Each Prelude Forty system features four MRS flat panel drivers in each cabinet – 2 midrange and 2 midbass drivers. They’re manufactured using the companies proprietary Ceramic Metal Matrix Diaphragm (CMMD) material, which is manufactured by anodizing a ceramic compound to both sides of a flat-panel aluminium core. This technique produces driver diaphragms of ultra-low mass and ultra-high rigidity, giving excellent sonic resolution and transient response.

The MRS driver also incorporates a number of further refinements. It uses two large elliptical voice coils, rather than a single conventional round voice coil with powerful rectangular neodymium magnets. This provides maximum contact and superior coupling between the voice coils and the diaphragm, resulting in increased efficiency and dynamic capability.

Infinity’s MRS driver employs another unique engineering feature in the form of the Same-Plane Surround suspension. In a conventional cone driver, the outer edge of the cone and the surround are located on a different geometric plane than the voice coil, a configuration that can cause the cone to rock back and forth as it moves creating audible distortions. The MRS drivers Same-Plane Surround technology eliminates this effect by placing the edge of the MRS diaphragm and its surround on the same plane as the driving force from the voice coil.

Accompanying the MRS drivers are a CMMD tweeter with a frequency response beyond 40kHz, ensuring that audible high frequencies (up to 20kHz) are smooth and highly detailed. The tweeter operates in conjunction with a cast-aluminum Constant Acoustic Impedance (CAI) waveguide, which utilizes a series of computer-designed, graduated curves that flare from the inside to the outside of the waveguide to provide optimal on and off axis high frequency dispersion and clarity, along with higher sensitivity and smoother roll off.

Taking care of the bass duties are dual 8-inch CMMD woofers incorporating a 2-inch, edge-wound ribbon voice coil, high-Gauss neodymium magnets, cast-aluminum frames and are magnetically shielded to boot. The high output woofers operate with very minimal distortion and are placed opposite each other in a side-firing arrangement - a design that enables the internal acoustic output from each woofer to cancel each other out within the enclosure, resulting in powerful low frequencies.

Premium grade internal components are employed including oxygen-free-copper wiring, three separate crossover circuit boards, low-inductance resistors, audiophile-grade capacitors and laminated-steel inductors. The enclosure of the Prelude Forty is also extensively braced to reduce internal resonances to below audibility. Useable frequency response is rated from 42Hz-40kHz with a sensitivity of 85dB and nominal impedance is 8 ohms. Recommended amplifier power can be anywhere from 50-250 watts RMS.

Available in high gloss black and real-wood cherry and rosewood, the Infinity Prelude Forty loudspeaker shios from this month at a suggested retail price of USD$6,000 each.

Tim LeFevre

View gallery - 8 images