Infinity Reference 51i Floor standing speakers
Infinity Reference 51i is a three-way bass reflex speaker system. The number of drivers matches the number of bands: an inch dome tweeter, a 130mm cone midrange driver and a 210mm woofer. One of the main advantages of the Reference series loudspeakers are the radiating elements of the drivers: tweeter domes and cones. The composite used in their manufacture is formed by sintering carbon and Kevlar fibers (APG technology). The structure obtained in this way has unique properties, combining high stiffness with low density. Such material is also an excellent energy absorber of elastic deformations. Driver cones are made of graphite-coated APG composite; the same composite structure was used in the manufacture of the tweeter dome. Band separation occurs at frequencies of 400 Hz and 3 kHz. The possibility of separate connection of drivers is provided. The bass-reflex port is placed on the rear panel. The low mass of the diffusers to a large extent contributes to an increase in sensitivity, which, according to our data, is 90 dB. The characteristic of the input resistance module has the following parameters: average value 7 ohms, nominal 3.4 ohms, standard deviation ± 2.1 ohms, maximum (50 Hz) 11.5 ohms. The bass reflex is set low (30 Hz). Both high sensitivity and stable input impedance allow you to count on good results even with a modest amplifier; the recommended input power range is 25-150 watts. The system provides a fairly high field uniformity. The body walls are reinforced with internal braces. In addition to absorbers, the reduction of wave resonances of the air volume is facilitated by a casing that hermetically closes the back of the mid-frequency head. The appearance of the speakers reflects the high skill of designers: one can feel the inner harmony of the chosen style. Loudspeaker dimensions: 274x890x275 mm.
The sound quality puts the system at the forefront of our podium. Note that the results of our measurements are in excellent agreement with the data given in the technical description. The average non-uniformity in the range of 100 Hz-20 kHz was only ±1.9 dB. Of course, from such a loudspeaker you can demand and receive musical sound of very high quality. I don't want to deal with the traditional anatomy of a sound image for the simple reason that all its aspects form a harmonious unity! The origins of the vitality of this unity are in the transparent detail of the upper frequencies, and in the bright expressiveness of the middle ones, and in the restrained power of the lower ones. But high quality also breeds excessive exactingness. And what you don't pay attention to in a system of average quality begins to take on importance in the case of a sound master. We began to examine the bass with passion and came to the conclusion that it seemed to be a little blurry and protruding. It was not possible to establish the boundaries of the dynamic range in the conditions of our listening room, even using the coolest musical material. The 51i stereo pair provides an excellent detailed panorama of the scene, imaginary sound sources are well structured in front and depth. A convincing effect of presence is created; the acoustic characteristics of the halls are clearly read.
