Martin Logan Preface

Características técnicas: Preface, like every MartinLogan product, meticulously advances those recognizable characteristics of passion and performance that consciously equate to pride of possession and elevated quality of life. At first sight and first sound, you know this is truly a MartinLogan, just for you. Key to Preface's performance is our ATF™ (Advanced Thin Film) drivers. Superior in almost every way to conventional moving-coil transducers (cones and domes) – and very similar in most respects to the electrostatics that we've always favored – ATF drivers project a wonderfully detailed and three-dimensional sound field. Our proprietary Vojtko™ crossover topology marries the ATF drivers to triple high-resolution 6.5-inch woofers, whose quick, precise bass provides the speaker's sonic foundation. Fully compatible with all audio/video equipment, Preface excels in almost any application, whether as a stereo pair in a music system or as front or surround speakers in a home theater setup. Advanced Thin-Film Drivers Based on RADIA planar technology, high-resolution ATF™ drivers approach the clarity and detail of our electrostatic panels while permitting the use of a compact cabinet. Each MartinLogan ATF transducer has a micro-thin, low-mass diaphragm with an ultra-light, etched aluminum conductive surface, suspended between two opposite-polarity, high-field-strength neodymium magnet arrays. When the electrical audio signal from an amplifier passes through the diaphragm's surface, it creates an alternating electromagnetic field that interacts with the fields of the fixed magnet arrays, forcing it back and forth to produce sound waves in the air. The strength and polarity of the diaphragm's field varies according to the audio signal. ATF Driver High-resolution ATF (Advanced Thin Film) drivers Like our electrostatic panels, ATF drivers are push-pull transducers: When the diaphragm's field polarity is the same as that of the magnet array on one side, pushing them apart, it is the reverse of the polarity on the other side, pulling it toward that opposing array with exactly the same force. This mode of operation is inherently linear. Another similarity to electrostats is that the diaphragm is driven uniformly over its entire surface, rather than at just a small contact area as in a conventional cone or dome driver. These two characteristics ensure precise, accurate reproduction with vanishingly low distortion. The diaphragm substrate is Dupont Kaladex® PEN (polyethylene napthalate). This material is chemically akin to the PET (polyethylene terathylate) film used for the diaphragms of our CLS™ Generation 2 electrostatic panels, but capable of handling the heat generated by the current passing through an ATF diaphragm's thin aluminum skin. Three Low-Distortion Woofers Triple Low-Distortion Woofers Triple 6.5-inch low-distortion woofers Utilizing the same motor and chassis structure as the innovative Purity, Preface's triple state-of-the-art, 6.5-inch, high-resolution woofers deliver a precise low-end with accuracy and authority. Vojtko™ Crossover State-of-the-art crossover engineering ensures a transparent link between the ATF™ transducer and woofers. Preface's crossover employs proprietary Vojtko topology for vanishingly low distortion and seamless driver integration. Designed and manufactured with the same meticulous attention, care and precision as crossovers found in MartinLogan’s ultimate loudspeaker products, this precision-tuned network preserves miniscule sonic nuances while handling the full dynamics of any source with unparalleled purity, precision, clarity, and openness. Toolless Binding Posts Toolless Binding Posts Toolless binding posts MartinLogan's proprietary toolless binding posts make cable connection and management easy. Energy Transfer Coupler Spikes The Preface is supplied with sturdy, 1/4-20 MiniETC™ spikes, which can be used in place of the standard feet to enhance stability on thick carpets or to create tighter coupling between speaker and floor. MiniEtc Spikes MiniETC™ (Energy Transfer Coupler) spikes Application Versatility Preface's size, styling, and performance make it suitable for almost any speaker application, even in combination with our electrostatic models. In small rooms or large, as part of a stereo music system or in a home theater as fronts, surrounds, or both, Preface delivers. Preface Specifications Frequency Response: 35–20,000 Hz ± 3dB Sensitivity: 92 dB/2.83 volts/meter Impedance: 4 ohms nominal Crossover Frequencies: 2200 Hz Components: Air core coils and large steel laminate inductor, polyester film capacitors in series and low DF electrolytic capacitors High Frequency Driver: 1.5" × 2.25" (3.8 × 5.7 cm) ATF™ Transducer Woofer/Midrange Type: 3 × 6.5" (16.5cm) cast basket, paper-cone, non-resonant asymmetrical chamber format; bass reflex Power Handling: 200 watts per channel Weight: 46 lbs./channel (20.9 kg) Dimensions (HxWxD): 39.6" × 9" × 17" (100.6 × 22.9 × 43.3 cm)