Overcoming bias in evaluating large American speakers remains a challenge. The ongoing discussion about the distinct sound characteristics of hi-fi systems from various countries has led to enduring stereotypes regarding the American approach, particularly the preference for pronounced bass and a somewhat relaxed handling of the rest of the sound spectrum. But is this perception accurate?
This curiosity is heightened with the introduction of the S60 floor-standing “towers,” the premier acoustics of the Signature series, emblematic of Polk Audio’s “signature” sound. Polk Audio stands as one of the top-selling audio brands in the United States, further emphasizing the significance of these speakers.
Design
High sales volumes typically imply mass production, which necessitates designs that can be efficiently and easily manufactured under current factory conditions. This often results in technology that is geometrically straightforward, such as rectangular shapes. Unfortunately, this approach can sometimes compromise the sound quality of speakers, even those produced by reputable brands in a similar price range.
The Polk Audio Signature series breaks away from the norm with its design intricacies. Unlike the straightforward rectangular shapes often seen in mass-produced speakers, these units feature gently rounded edges along the horizontal ribs of the body, revealing a complex design upon closer examination. The cabinets, while not concealing their vinyl finish, are impeccably crafted without any visible defects. Available in three finishes—white, black, and a natural brown with a walnut texture—they cater to a variety of aesthetic preferences. The design is further accentuated by several pairs of rugged hex head bolts that contrast sharply against the cabinet’s flawless surface, embodying an industrial rather than luxurious aesthetic.
The speaker arrangement within the cabinet is also noteworthy. The upper two-thirds of the cabinet houses four speakers, and three identical low-mid-frequency drivers are positioned below. These drivers feature plastic diffusers with concave dust caps that blend seamlessly with the front panel’s texture. For those who prefer a more understated look, a magnetic fabric grill is provided. This grill can cover the entire front of the speaker from top to bottom, offering an alternative appearance that is entirely neutral.
At its base, the S60 features four supports that extend beyond the dimensions of the tower, significantly enhancing its stability. When the grill is removed, this design choice gives the speaker an almost ethereal appearance, as if it’s floating on air, thanks to a modified version of the Polk Power Port Deep Bass technology. This unique structural design sets the S60 apart from the typical “floor-standing” speaker genre.
The design and performance of the S60 are deeply influenced by Polk Audio’s patented Dynamic Balance technology, which is a cornerstone in the development of their products, alongside the use of the Klippel system. Polk Audio’s engineering team focuses on analyzing each speaker component as a collection of electroacoustic and mechanical parameters. The aim is to optimize material selection and geometry of the moving parts. This technology is pivotal in identifying and addressing potential issues that could impair sound quality, even during the design phase, thereby streamlining the development process for new models. However, it’s noted that this approach limits the variety of speaker designs available.
Starting from the top and moving downward, the highlight begins with the tweeter. The S60 features a newly developed Terylene dome tweeter that incorporates ferromagnetic fluid in the magnetic gap for cooling. This tweeter is designed with a curved waveguide that significantly broadens its dispersion pattern. Visually, it resembles a horn with a notably wide opening, taking the form of a body of rotation; it proudly displays the brand’s name, its founding year, and heralds the essence of “American HiFi,” as discussed earlier.
The dome of the tweeter is somewhat flatter compared to most counterparts and is encircled by a unique single-wave suspension crafted from the same material. The external appearance is textile-like, likely treated with a coating that gives it a slightly rough, silvery-yellowish texture. The tweeter’s specifications command respect, boasting an upper frequency limit that is double the traditionally recognized audible threshold. This design choice suggests the tweeter’s proficiency in handling higher harmonics, contributing to a sound that is both natural and effortless. Additionally, the resonance frequency is lowered, a logical and fitting adjustment considering the design nuances of the S60’s mid/low range components.
In the design of the Polk Audio S60, the creators employed some clever techniques. Positioned below the tweeter, three identical drivers are arrayed in a row. These drivers emit a “lunar shine,” a result of using a polypropylene-mica composite material, and are encased in black butyl rubber surrounds. The manufacturer highlights features such as voice coils wound in four layers, the inclusion of ceramic elements, and dual magnets to ensure field uniformity across the entire length of the voice coil’s movement.
However, categorizing the Polk Audio S60 based on the number of bands it supports is somewhat misleading. The rear panel of the cabinet features gold-plated speaker terminals that allow for traditional two-wire connections or bi-wiring by removing the connecting jumpers. The technical specifications even list the LF-HF crossover frequency. At first glance, one might consider these floor-standing speakers as two-way systems, equipped with a single tweeter and three woofers. Yet, this simplistic classification doesn’t fully capture the innovative design and performance nuances of the S60.
The Polk Audio S60 incorporates a sophisticated cascade crossover network featuring film capacitors and air core inductors in the high-frequency (RF) section. Polk Audio asserts that this design “delivers a seamless, lifelike soundstage across the entire audible spectrum.” To break this down further, the driver closest to the tweeter functions in a traditional midrange role as seen in two-way systems, with its output sharply defined at the upper end to seamlessly integrate with the tweeter at the crossover frequency noted in the documentation. This middle driver also extends its reach into the low frequencies, though it stops just short of the high-frequency driver’s range.
The lowest positioned driver is tuned for standard bass reproduction, mimicking its role as if it were part of a three-way system. Each transition in the frequency response of the drivers is characterized by its unique slope. Consequently, at the lowest frequencies, all three drivers work together, providing a combined radiating surface equivalent to that of a classic ten-inch woofer. As the frequency increases, this effective radiating area logically decreases in a stepwise manner, ensuring a balanced and dynamic sound reproduction across the spectrum.
One might assume that Polk Audio’s decision to use three identical drivers in the S60 was a cost-saving measure typical of mass production. However, the Signature series, to which the S60 belongs, showcases a dedication to quality and specificity in design choices. For instance, the S10 bookshelf speaker from the same line features a smaller 4-inch midrange driver unique to that model, indicating that the use of identical drivers in the S60 is a deliberate design choice rather than a compromise.
A closer inspection of the speaker’s base reveals another layer of Polk Audio’s engineering finesse. The cabinet’s base is constructed using a non-resonant MDF material known as Meddite, part of Polk Audio’s proprietary Power Port Deep Bass technology. The Power Port is a patented bass reflex port design aimed at enhancing low-frequency response. It is oriented downward, leading towards a coaxial cone mounted on the base plate with a concave curvilinear shape. This innovative design creates a circular counter-aperture channel that distributes airflow smoothly and uniformly across 360 degrees in the horizontal plane, contributing to the speaker’s efficient and expansive bass performance.
The core objective behind the design is to enlarge the port’s cross-section, thereby ensuring a laminar airflow without turbulent disturbances. This approach lays the foundation for the S60’s bass sound, characterized by its clarity and depth. The speaker’s design, including the four supports positioned at the corners and even the grill covering the front, is meticulously crafted to not interfere with the circular radiation pattern. This design philosophy significantly minimizes the effect of the speaker’s placement on its bass performance, offering greater flexibility in room positioning without compromising sound quality.
Furthermore, Polk Audio’s innovative approach to the bass port design not only enhances sound delivery but also boosts the system’s efficiency in the low-frequency range. According to various sources, this efficiency is increased by approximately 3-6 dB. Such an improvement in efficiency translates to a more powerful and dynamic bass response, enriching the overall listening experience with fuller and more resonant low frequencies.
Sound
Polk Audio markets the S60 as a definitive “true American HiFi speaker for home theater,” highlighting its versatility beyond just a cinematic experience. Its design and specifications enable it to perform exceptionally well as a stereo pair for music listening, without any need for compromises in quality or performance.
Sensitivity is a standout feature of the Polk Audio S60, indicating the speakers’ ability to efficiently convert amplifier power into sound. This characteristic suggests that the S60 speakers are highly adaptable to a range of amplifiers. Whether it’s a modern, powerful solid-state or digital amplifier or a vintage system known for its warm and distinctive sound, the S60 is designed to perform well, showcasing its flexibility and capacity to bring out the best in any audio setup.
In a practical application, the S60 was tested with a high-quality listening setup including the ORPO BDP-105D player, Classe Sigma SSP mk II preamplifier-processor, and Classe AMP 2 power amplifiers. This configuration, capable of driving the speakers to nearly their full potential, was chosen to initiate the evaluation, aiming to explore the breadth of performance the S60s could offer when paired with top-tier audio equipment.
The S60 speakers demonstrated their capability to deliver consistent sound quality across a broad volume spectrum. In a room of approximately 25 square meters, they proved powerful enough to entertain a gathering of a dozen lively guests, potentially extending the party vibes to neighboring listeners as well. The playback of Daft Punk’s “Get Lucky” showcased the speakers’ ability to produce serious club-like sound fidelity, free from distortion, characterized by elastic, deep, and substantial bass that was not just audible but physically palpable.
Upon adjusting the volume to a more refined level, the exploration continued with a variety of test soundtracks, beginning with the classics. Grieg’s “In the Hall of the Mountain King” from “Peer Gynt, Suite No. 1, Op. 46” was particularly revealing of the S60’s strengths in microdynamics and clarity. Even during the crescendo where all instruments reached a fortissimo, the sound did not degenerate into a chaotic jumble. Instead, it remained possible to mentally separate and identify the components of virtually any instrument group within the symphony orchestra. This experience was further enhanced by a soundstage that was slightly elevated yet distinct and well-separated from the source. Furthermore, the optimal listening area, or “sweet spot,” was found to be remarkably generous, both in width and depth, accommodating a wide range of listening positions without sacrificing sound quality.
Continuing the auditory exploration, the S60 speakers present female jazz vocals, as heard in Sinne Eeg’s “My Treasure,” with vividness that borders on being overly bright for some tastes. This characteristic brightness extends to the reproduction of violin and wind instruments in chamber music, highlighting a potential preference for a more pronounced high-end. The bass guitar on tracks like “Knock Out” by Band Waggon, while emotionally engaging, might benefit from a tighter, “drier” sound for some listeners. The S60s, through their delivery, veer away from a neutral “monitor” sound, fully embracing a sound profile that is rich in emotions and distinctly assertive—qualities that can be described as quintessentially American.
This distinct sound signature of the S60s shines through on tracks recorded with a raw, unfiltered approach, such as Billy Gibbons from ZZ Top’s “Treat Her Right,” where the speakers manage to convey the music’s energy and texture with remarkable ease. Likewise, AC/DC’s “Thunderstruck” is delivered with full-range bravado, capturing the essence of the band’s spirited performance without any hint of compromise. Through these listening experiences, the S60s assert their character, offering a sound that is bold, emotional, and unapologetically American, catering to those who appreciate a lively and dynamic musical presentation.
Conclusion
The Polk Audio S60 speakers defy easy classification into a specific genre preference, showcasing their versatility across a wide array of musical styles, from electropop to live organ music. This adaptability is contingent upon a listener’s appreciation for robust bass and a genuine interest in the musical content. The S60s excel in delivering a dynamic range that spans from impactful lows to the finest details in the upper registers, making them exceptionally universal in their musical applications.
While they have a pronounced capability for music playback, it’s essential not to overlook their designated role in home cinema setups. When deployed as front speakers, the S60s are so proficient in covering the lower frequencies that the addition of a subwoofer becomes optional rather than necessary. This feature highlights the speakers’ dual functionality, allowing them to serve effectively as both a stereo pair for music listening and as integral components of a surround sound system, thereby offering a comprehensive audio solution for a wide range of listening preferences and scenarios.
