Surround Sound Speaker Systems
- Written by Tyler Stripko
- Published on 02 December 2011
Design of the Polk RTiA 5.1 Home Theater Speaker System
The foundation of this system is the RTi A9 towers. The largest speaker in the RTi A series, the A9 is an imposing design, measuring 48-5/8 inches tall by 21-3/8 inches deep. Width is a more modest 8-7/8 inches. I'll get this out of the way up front: the RTi A9 is NOT for those of you with small rooms. In anything shy of a 15' x 20' room, the A9s will most likely dominate the floor plan. Even in my 16' x 22' media room the A9s were almost visually overpowering, making my 50-inch plasma TV look like a 42-incher (perfect excuse to upgrade to a 65+" display or front-projector if you ask me). Personally, I like large floor-standing speakers, but if you have a smaller room, I'd target either the smaller A7 or A5 towers. Not only will they appear a bit less menacing, but they will also keep you from overpowering the room sonically. The driver complement of the 3-way A9 includes a 1" silk polymer composite tweeter flanked above and below by two 5-1/4" polymer composite midrange drivers in a classic D'Appolito array, and three 7" polymer composite woofers. The tweeter is crossed to the midrange at 1.8kHz via a 12dB/octave low/high-pass filter which subsequently runs to a 120Hz, 12dB/octave high-pass filter for the midrange drivers. The woofers are serviced by a separate 120Hz, 12dB/octave low-pass filter. The tweeter and midrange are housed in a sealed compartment of the tower, while the woofers are in a ported section of the cabinet which uses Polk's "PowerPort Plus" design. Dual 5-way binding posts on the back of the cabinets allow for bi-wiring or bi-amping. The A9s arrive with rubber feet for placement on wood or tile floors, but carpet spikes are also included if you need them. Simply unscrew the rubber feet and screw in the carpet spikes and you are all set.
The CSi A6 is larger of two available matching center channel speakers and sports a single 1" silk polymer composite tweeter between two 6-1/2" polymer composite mid/woofers. While not exactly small at 7-3/4" high x 24" wide x 14" deep, the A6 is not as visually imposing as the A9s and should fit well on most media shelves or racks. Around the back of the speaker are two pairs of 5-way binding posts to facilitate bi-amping or bi-wiring. There is also a bracket that can be used with Polk's innovative "kickstand" attachment to mount the CSi A6 on top of CRT or rear-projection televisions with sloping rear cabinets. Sadly, the kickstand won't work with the latest flat-panel TVs as-is, but I'll bet that some of our more creative readers can figure out a way to make it work. Polk even includes some clear self-stick feet to place on the bottom of the A6's cabinet if you are going to place the speaker on a surface that could mar the wood veneer.
For the surround channels, I chose to go with the larger of the two bookshelf speakers in the RTi line; the A3. While Polk offers two dedicated bipole/dipole surrounds in the FXi A6 and FXi A4, I personally prefer a more traditional speaker for surround usage. The reason: multi-channel music. While bipole surrounds may help to create a bit more diffuse surround field for movie soundtracks, they lack the focus and clarity that I prefer with multi-channel music sources such as SACD, DVD-Audio, or Blu-ray audio discs. The A3 sports a single 6-1/2" polymer composite midrange/woofer crossed over to 1" silk-polymer tweeter via a 12dB/octave high and low pass crossover set at 2.8kHz. On the backside of the A3's 14-3/4" high x 8-7/8" wide x 14" deep cabinet is a single Polk PowerPort and dual 5-way binding posts that allow for bi-amping or bi-wiring. The cabinets of the A3 sport the same beautifully curved sidewalls as the A9.
To supplement the low end, Polk sent along the DSWPRO660wi powered subwoofer. This is Polk's largest sub in the "wireless ready" line and sports a 12" woofer driven by a 500-watt amplifier in a slot-ported, relatively compact 17-1/8" high x 16-1/2" wide x 16-1/2" deep cabinet. The matte-black finish of the subwoofer helps minimize its visual presence in a room, but if you prefer to match either of the wood veneer finishes on the RTi series speakers you are out of luck. The DSWPRO660wi can be set up with the woofer facing down for standard open air operation (say on your floor in the corner) or with the woofer facing forward if you need to mount the sub within a cabinet. If installing the sub in a cabinet make sure to face the woofer cone towards the cabinet opening for best sound. Polk even includes an extra set of feet that can be installed if you choose the front-firing option. I also appreciated the design of the main feet for the sub. The sub arrives with 4 rubber feet installed. These are great for wood or tile floors, but what if you have carpeting? Simple: just pull on the rubber foot and it slides off, revealing a nice study carpet spike. In about 30 seconds I had the four rubber feet removed and was ready to place the DSWPRO660wi on my carpeted floor.
Polk also included the optional PWSK-1 wireless kit ($119.99) with my subwoofer. Consisting of a transmitter module that plugs into the LFE or sub pre-out on your pre-pro/receiver and a smaller receiver unit that plugs into a dedicated port on the control panel of the sub, the PWSK-1 kit allows a user to feed an uncompressed signal to the subwoofer without the difficulty or running any wires. This makes it far easier to setup your subwoofer where it will deliver the best bass performance in your room, not just where you can easily run the required cabling. You will still need to have an AC receptacle near the sub to provide power for the amplifier, but that is all that is required. The PWSK-1 also has multiple frequency channels, so you can setup more than one wireless subwoofer if desired. Following the "wireless" trend, the DSWPRO660wi also includes a handy little remote control that you can use for adjusting subwoofer volume, phase, room position, and status light indicators.
Considering the list prices, I was extremely impressed with the construction quality of the A9, A3, and A6 speakers. Fit and finish was excellent on all speakers and the black real-wood (I'm guessing oak or ash) veneer was smooth and supple. Even more surprisingly, it is nearly impossible to detect the seams where two veneered panels meet – bravo Polk. The curved side cabinet walls lend a very elegant look to the speakers, as well as work to reduce internal standing waves. Overall, the cabinets feel very solid, though knocking my knuckles against the lower cabinet sides on the A9s and A3s (where the bass drivers reside) resulted in a bit of resonance. The upper half of the A9 (which houses the tweeter and midrange drivers in a separate sealed compartment) produced a totally inert "thunk" when struck. The dual 5-way binding posts are solid and accepted the banana posts from my Kimber cabling without issue. Just don't forget to remove the jumpers between the two pairs of posts if you intend to bi-amp or bi-wire. The speaker grilles are your typical black cloth stretched over a plastic frame, but are nicely designed with a neat "techno-esque" metallic edging along the top and bottom of the grille. The grilles use simple push-in posts to mount to the front baffle of each speaker and are easy to remove. I really liked the way the speakers looked without their grilles as the combination of black veneer with the silver/platinum color of the drivers and front ports gives off a very modern vibe. The DSWPRO660wi was also solidly constructed, though at only 45 pounds, it is quite a bit lighter than most subs I've used with a 12" driver. Surprisingly, the matte finish on the sub seemed to show fingerprints and smudges almost as badly as the piano-gloss finish on my current Hsu Research sub, but a thorough wiping with a soft cotton cloth cleaned things up nicely.