since the introduction of its new RTi line in early 2007. In addition to real-wood veneers, the line packs an incredible amount of design elements into its affordable models, many of which Polk uses in its most expensive offerings. The series offers three floorstanding models (RTi A9, RTi A7/reviewed here, RTi A5), two bookshelf models (RTi A3, RTi A1), two center models (CSi A6, CSi A4), and two surround models (FXi A6, FXi A4).
The second to the top of the line, the RTi A7 shares some traits and design elements with its big brother, the RTi A9
. First, it's not exactly small. Measuring 42.25 inches high by 8.875 inches wide by 17.875 inches deep and weighing 55 pounds, the RTi A7 makes a stunning, tight visual impression. On the top, the design employs a 1-inch Silk Polymer Composite Dome Tweeter crossed over at 2.7kHz and 12dB per octave to one 5.25-inch Dynamic Balance midrange driver. Unlike the dedicated housing for the tweeter/dual-midrange array utilized in the A9, Polk instead takes a more traditional approach with the A7, with the tweeter and midrange sharing the same airspace as the rest of the design, but supplemented by a small front port employing Polk's patented ARC Acoustic Resonance Control (ARC)
Technology, which streamlines airflow to clarify the midrange. Developed in conjunction with Johns Hopkins University, Dynamic Balance
resulted from a laser interferometry research project that enables Polk to analyze the entire surface of a vibrating driver in real time, in order to determine the right combination of materials for the particular product. The midrange driver crosses over at 125Hz at 12dB per octave to two 7-inch Polymer Composite woofers. The RTi A7 also utilizes the company's PowerPort Plus technology
, which consists of two ports - one front and one rear firing - supplemented by internal "plates" to reduce air turbulence and increase efficiency. Located under the woofer array, the large front port fits nicely into the cabinet with a silver fitting. The very slick rear port puts a cone at the mouth of the port to streamline airflow, reduce chuffing, and smooth out frequency response. But unlike most ports that simply end at the edge of the cabinet, Polk uses an elegant plate to terminate the PowerPort, which adds a wonderful cosmetic touch (For those not keeping track, that makes a total of three ports on this speaker...not common.). The RTi A7 provides two sets of 5-way, gold-plated binding posts for bi-wiring/bi-amping
. As with all the RTi designs, the RTi A7 features real-wood veneer side panels and utilizes an elegant, tapered cabinet design, which looks great on a big speaker while also likely improving performance by minimizing and diffusing internal standing waves. Generally (although it has to be executed properly, of course), less boxy designs have the potential to sound better, as they can cancel internal resonances and quiet the enclosure. To that end, Polk also utilizes its DAHLI (Damped Asymmetric Hex Laminate Isolation) technology to thoroughly brace the cabinet with a six-layer laminate with five viscous layers. The RTi A7 offers two optional veneer finishes - Cherry and Black - with the Cherry really distinguishing itself. The removable grills, with nice looking molding on the top and bottom creating an elegant blend into the baffle, look good but their plastic construction sticks out just a tad. Without the grills, the drivers look great against the baffle. As with all the models in the line, the overall fit and finish of the RTi A7 sets a very high standard for the price point.
The RTi A7 presents a nominal 8 ohm load with an 89dB efficiency. It needed very good power to open up properly, and only got better as the amplifiers and receivers improved.
Very much like the A9, the RTi A7 delivers a forward, immediate sound quality that delivers a sharp attack and plenty of body. They threw a very deep and wide soundstage with plenty of imaging outside of the speakers, and crisp outlines. The treble sounded a little edgier than the A9, but retained just enough smoothness to keep it in stride. The midrange offered very good clarity and speed, with a natural character that lent itself to voices, in particular. The midrange port really impressed, as it did its job quietly and added good body to the lower mids and a pleasant bloom to the sound...one port down, two to go. Getting into the lower registers, the RTi A7 provided a good blend of punch and thump. Every now and then, things got a little sloppy in the midbass on rock and electronics tracks, but never at the expense of overall coherence. The RTi A7 excelled on acoustic and classical material throughout the sonic spectrum, but especially in the mids and bass. It offered a terrific balance of heft and focus, and scaled nicely with large scale classical material. The large, yawning front port exhibited very little noise, and rounded out the bottom very well. As for the smaller rear port, noise doesn't factor in at all and its refined, focused design probably contributes to the RTi A7's ability to draw such a good bass balance. It has just enough weight to round things out while retaining its terrific punch across all types of material. At high volumes, the RTi A7 sounded terrific, and almost improved on a couple of occasions. Closer to walls, despite the mostly front porting, the sound thickened and degraded in quality a bit. This design, like its big brother, needs room.
Competition and Comparison
To compare the Polk RTi A7 loudspeakers against their competition, read our reviews for the Boston Acoustics CS 226 loudspeakers and the Klipsch Synergy F-1 loudspeakers. You can find more information on different products available in out Floorstanding Speaker section.
Read more about the RTi A7 on Page 2.