Crossover to serious audio
The folks at Polk are unabashed about pointing out that the new LSi Series LSi25 floorstanding loudspeaker has been designed for use with high definition audio sources like SACD and DVD-Audio. Now, while the LSi25's woofer, midrange, and tweeter drivers have the technological backing to do high definition audio justice, there is stil an intermediary step that needs attention — crossover. Because no single driver can accurately reproduce all of the frequencies of a given recording, most loudspeakers contain multiple drivers (each optimized for reproducing a particular frequency range), and an electronic filter known as a crossover that splits an audio signal into the different frequency bands suitable for each driver. Clearly, fidelity of the sound reproduced by a loudspeaker's drivers depends heavily upon the efficiency and effectiveness of the loudspeaker's crossover mechanism. The LSi25 features both premium crossover components — delivering consistent high-end sound quality — and a mylar bypass capacitor in the high-pass crossover, extending and flattening high frequency response. Hear details you've never heard before, even in your favorite tracks. (Additionally, while sold singly, this right-channel LSi25 can be matched with a mirror-image left-channel LSi25 for tightly focused highs and true three-dimensional imaging with minimized room reflections.)
Your audio's foundation — Bass
Let's get to the bottom of things. No home audio experience is complete without sufficient, nay, ample low-frequency reproduction. That is, without enough bass . . . but not that sloppy 12"-woofer-in-the-back-of-a-teenager's-first-car kind of bass. Oh no, we're talking about accurate, high-performance bass. The LSi25's 10" polymer-composite-cone woofer driver features its own 150W built-in amplifier for powerful, full-range bass. But that's only part of the story. The LSi25's bass performance is also enhanced by Polk's PowerPort vented enclosure. Vented systems use the sound produced at the rear side of the driver's diaphragm to increase the efficiency of the system at low frequencies by taking advantage of the resonance of ports or vents designed into the enclosure. The air mass in the cylindrical ports resonates in response to the movement of the air behind the diaphragm within the enclosure, similar to the way that the air in a glass bottle resonates when you blow air across its mouth. Dynamic bass performance. Check.
Two midrange drivers . . . a host of technologies
The LSi25's two 5.25" midrange drivers have their foundation on several audio-enhancing technologies. First, unlike with bass, when it comes to midrange frequencies, cabinet resonance is a problem. Polk's patented Acoustic Resonance Control (ARC®) port system overcomes the distortion produced behind midrange drivers by means of a second small port that is tuned to suppress internal cabinet resonance. Second, Polk's Cascade Tapered Array crossover design separates troublesome upper and lower midrange frequencies between the two drivers to dramatically reduce sound-image-degradation that might otherwise result from interference between the drivers. Third, using laser-imaging, Dynamic Balance® technology has allowed the folks at Polk to create the right combinations of materials, driver geometry, and construction techniques to produce flat frequency response, sharp detail, transparency, and dynamic wide-range audio reproduction. Finally, an aerated-polypropylene construction features perfectly balanced thickness, density, and stiffness, allowing the LSi25's mid-range drivers to achieve exceptional accuracy.
The tweeter
The incredible accuracy and astonishing detail achieved by the LSi25's 1.0" tweeter has but one source — a ring-radiator tweeter design. Every element of the ring-radiator tweeter's design is aimed at revealing all the nuances in your favorite songs and soundtracks. The Ring Radiator Diaphragm delivers flat response, precise detail, and overall accuracy thanks to an ultra-light woven diaphragm that reduces resonance by leaving very little material unsupported. A high-frequency waveguide prevents phase cancellations for smooth frequency response and wide dispersion, while a low-frequency waveguide promotes laminar airflow between chambers in the dual-chamber cavity, thus reducing air turbulence. Flattening the impedance curve, lowering distortion, and extending high-frequency response is a copper "Faraday Cap" on the pole piece. Additionally foam and Dacron cavity-fill materials absorbs the diaphragm's back-wave radiation for flatter frequency response.
Beyond the drivers
A speaker is a unit . . . a perfect blend of a variety of components that operate in unison to deliver an impacting audio experience. While much time is devoted to discussing driver technology, a speaker's cabinet design is of equal importance, as poorly designed enclosures can resonate with the drivers, creating unwanted interference and distortion. First, the LSi25's glass-filled composite baffle provides a dense, acoustically inert platform for the speaker's high-end components, protecting the drivers and enhancing their performance by reducing resonance. Also, 1.5"-thick side panels make the enclosure acoustically inert for reduced cabinet interference. Next, a low-diffraction grille uses an open-architecture design to deliver spacious imaging. Finally, Composite Driver Baskets® keep the LCSi25's drivers' moving parts in rigid alignment, thereby also damping performance-robbing resonance.
Secure, versatile connections
The gold-plated five-way binding posts featured on the Polk LSi25 are designed with wide holes for large-gauge bare-wire connections. This binding-post construction offers the most secure audio-cable connection, and is the most versatile wiring application available. Additionally, a dual set of binding posts allows for bi-amping of the LSi25.
The finishing touches
Go one step further in your quest to reach the pinnacle of home audio. A high-performance outdoor speaker like your new Polk Audio LSi25 can only help your home audio system reach its full potential if it is receiving a quality, high-integrity audio signal. Audio cables — chosen specifically for the needs of your system — deliver the ability to maximize your Polk LSi25's potential. View the accessories list attached to the Polk Audio LSi25 at Vanns.com or call a Vann's customer service representative at the 800 number at the top of this page for assistance in selecting the right set of cables.
