Surround Sound Speaker Systems
- Written by Tyler Stripko
- Published on 02 December 2011
Introduction to the Polk RTiA 5.1 Home Theater Speaker System
Founded in 1972 by Matt Polk, George Klopfer, and Sandy Gross, Polk Audio has always strived to deliver natural, full-range sound at a competitive price. While no longer run by the founders, Polk Audio still works hard to provide a high-quality sounding product at a price that mere mortals can easily afford. Recently refreshed, the RTi A series of speakers from Polk sports new curve-sided cabinets, upgraded drivers, and real-wood veneer finishes. For this review we've assembled a full surround system including the RTi A9 towers, CSi A6 center-channel, and RTi A3 bookshelf speakers for use as surrounds. Rounding out the system is Polk's DSWPRO660wi wireless-ready subwoofer. As Polk's second-most expensive line behind the LSi series, we'll see if the RTi system can offer similar performance to its more expensive siblings.
POLK RTIA SPECIFICATIONS
- RTi A9
- Design: 3-way Tower, Sealed and Ported Combination
- Drivers: One 1" Silk Polymer Composite Dome Tweeter, Two 5.25" Polymer Composite Mid-range, Three 7" Polymer Composite Woofers
- MFR: 30 Hz - 26 kHz, - 3 dB
- Nominal Impedance: 8 Ohms
- Crossover frequency: 120 Hz, 1.8 kHz
- Sensitivity: 90 dB
- Recommended Amplifier Power: 50-500 Watts
- Dimensions: 48.6" H x 8.9" W x 21.4" D
- Weight: 76 Pounds/each
- Standard Finishes: Black or Cherry Real Wood Veneer
- MSRP: $1,499.90/pair USD
- RTi A3
- Design: 2-way Bookshelf, Ported
- Drivers: One 1" Silk Polymer Composite Dome Tweeter, One 6.5" Polymer Composite Mid/Woofer
- MFR: 50 Hz - 26 kHz, - 3 dB
- Nominal Impedance: 8 Ohms
- Crossover Frequency: 2.8 kHz
- Sensitivity: 89 dB
- Recommended Amplifier Power: 20-150 Watts
- Dimensions: 14.75" H x 8.9" W x 14" D
- Weight: 16 Pounds/each
- Standard Finishes: Black or Cherry Real Wood Veneer
- MSRP: $399.95/pair USD
- CSi A6
- Design: 2-way Center Channel, Ported
- Drivers: One 1" Silk Polymer Composite Dome Tweeter, Two 6.5" Polymer Composite Mid/Woofers
- MFR: 55 Hz - 26 kHz, - 3 dB
- Nominal Impedance: 8 Ohms
- Crossover Frequency: 2.8 kHz
- Sensitivity: 90 dB
- Recommended Amplifier Power: 20-200 Watts
- Dimensions: 7.75" H x 24" W x 14" D
- Weight: 29 Pounds
- Standard finishes: Black or Cherry Real Wood Veneer
- MSRP: $399.95/each USD
- Design: Subwoofer, Slot-loaded
- Driver: One 12" Composite Polypropylene Woofer
- MFR: 20 Hz - 160 kHz, - 3 dB at 25 Hz and 125 Hz
- Amplifier Power: 500 Watts RMS, 1,000 Watts Peak
- Low-pass Crossover Range: 60 Hz - 120 Hz
- Dimensions: 17.1" H x 16.5" W x 16.5" D
- Weight: 45 Pounds
- Standard Finish: Matte Black
- MSRP: $ 649.95 USD
- SECRETS Tags: 5.1, Speaker Systems, Home Theater Speaker Systems
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.
Setup of the Polk RTiA 5.1 Home Theater Speaker System
Given the size of the A9 towers, I decided to setup the RTi system in my 16' x 22' main media room. Source components were my Integra DHC-9.9 pre/pro, Wyred 4 Sound 7 channel amplifier (550 watts @ 8ohms x 3 for the front channels, 250 watts @ 8ohms x 4 for the surround channels), and Oppo BDP-83SE NuForce edition Blu-ray player. Cabling was a mix of Kimber speaker cable and Blue Jeans HDMI, XLR, and RCA cables. I started with the towers about 3 feet from the back wall and 4 feet from the sidewalls. The CSi A6 was placed directly on top of my Salamander Designs Triple 20 TV cabinet. The A3 surround speakers were mounted on B-Tech BT-77 wall brackets and aimed directly at my primary listening position. This only gave the back of the A3s a few inches of clearance from the wall, but surprisingly led to very little bloat in the bass. The DSWPRO660wi subwoofer was installed in the same front corner spot where my reference sub is placed, as it provides the smoothest overall bass response in my listening room. Given that I had the appropriate cabling run, I did not use the PSWK-1 wireless kit though a brief trial confirmed that it worked exactly as advertised. Subwoofer setup was pretty easy with the included remote control. You can set the phase to 0, 90, 180, or 270 degrees (0 degrees worked best for me) right from the remote and you can also select from one of four preset position locations: cabinet, corner, mid-wall, or mid-room (I used corner). There is a separate button to disable the front panel blue LED light (it still lights up when receiving a command from the remote) as well as a "night" button that when pressed cuts the sub's volume level by 50%.
I have only two gripes about the operation of the DSWPRO660wi. First, you must count a series of short and long blinks of the front panel LED to determine the volume level which is not necessarily difficult, but annoying. Second, the remote sensor seems to have a very limited range. A wider reception range would be greatly appreciated as it would make the sub far more responsive to remote commands. I do wish to acknowledge the excellent instructions on the subwoofer, as they very clearly illustrate the multiple options for connecting the subwoofer to pretty much any system out there.
My initial listening sessions led me to move the A9 towers slightly further apart (now 3 feet from each sidewall), which improved imaging nicely. I also moved each tower closer to the back wall, finally settling on about 2 feet from the back wall. This extra foot of distance from my listening position (now about 10.5 feet from my ears) increased the coherence of the A9's sound without causing any noticeable bloat in the bass. As the A9 is a very large tower with multiple drivers I would recommend that you sit at least 10 feet from the front baffle to ensure that the sound gels together properly. If you don't have that kind of space, one of the smaller RTi towers would probably be a better idea. After experimenting with speaker toe-in, I found that I preferred the sound of the A9s with them firing towards a point slightly behind my head. This gave the smoothest overall mid-range/treble response while maintaining very good imaging. After spending some time comparing the sound of the A9s with and without the grilles, I found that I preferred them with their grilles off as there was a touch more detail in the upper mid-range and treble. To keep things consistent, I removed the grilles from the CSi A6 and RTi A3's for the remainder of my listening sessions. I also ran my Integra DHC-9.9 through a full Audyssey Pro calibration to ensure that all speaker distances and levels were appropriately set as well as to get some listening position measurements for each speaker.
The Polk RTiA 5.1 Home Speaker Theater System In Use
With my setup finally complete, it was time for some music. To get a sense of the basic character for the Polks, I started with my standard 2-channel reference disc, Rachmaninoff's "Symphonic Dances" on CD (Reference Recordings RR-96CD) played back via the analog outputs of my Oppo BDP-83SE NuForce edition Blu-ray player direct into the multi-channel inputs on my Integra pre/pro. I was very impressed with what I heard. The A9s clearly had the ability to deliver a "big" sound. The incredible dynamic range on the disc was easily reproduced at convincing volume, with no sign of strain or congestion. Even better, the more dynamic passages came through with excellent clarity and detail, without sounding the least bit harsh. Woodwinds were reproduced beautifully and the massed strings had just the right amount of "bite" to them. Imaging and sound staging were very good through the A9s, particularly given the $1,499 per pair price point. The silk tweeter's treble was clear and detailed, though not as airy as the ring-radiator tweeter used in Polk's higher end LSi series speakers (which are in the process of being replaced by Polk's new LSiM series – which will hopefully be in my hands sometime late fall '11). As I had hoped for given the multiple 7-inch drivers, bass was tight and extended.
Below is the frequency response chart for the A9 tower (sans grille), as measured by Audyssey Pro. Bear in mind that this is the measured frequency response at my listening position, so my room is influencing the sound here. The bumps at 50Hz and 100Hz are common room-related issues for me, though the ~5dB suck-out around 700Hz is not something I typically see. However, the rest of the frequency response is very smooth, with only a slight bump (~1.5dB) around 2.5kHz. At 30Hz, the A9 is only down about 5dB and there is still useful output down to nearly 20Hz. You could definitely run the A9s without a subwoofer and miss out on very little in the bass department.
As this is a review of a full surround system, I spent the remainder of my time listening to high resolution, multi-channel sources like SACD, DVD-Audio, and lossless Blu-ray soundtracks. I recently picked up a copy of "Britten's Orchestra" on SACD (Reference Recordings RR-120SACD) and I can definitely see why it won a Grammy award for best recording. Anyone who has been on the fence about multi-channel music should grab a copy of this disc. The increased resolution of the DSD source was evident in the absolute smoothness of the sound – so very analog-like in nature. The increased dynamic range afforded by SACD was well utilized as well, with tremendous swings between the softest passages and the most bombastic moments. The surround field was a model of perfection, with just the right amount of ambient effects in the surround channels and a very solid front soundstage. Bass had tremendous impact, though bass depth sounded slightly limited through the DSWPRO660wi sub. I quick glance at my pre-Audyssey measurements confirms my feelings: the PRO660 rolls off rapidly beneath 50Hz. As my reference Hsu sub has no issues reaching below 20Hz in a similar location, I don't believe that my room was the source of the problem. Moving the sub to other positions in the room did not improve the overall bass response.
Wanting to see how the CSi A6 center-channel would fare, I put on the DVD-Audio disc of the Beatles "Love" (Capitol B000JJS8TM) and went right to "While My Guitar Gently Weeps." George Harrison's vocal sounded haunting, yet absolutely beautiful through the A6 and I found myself listening to the entire song. The A6 is truly a full range speaker, and the difference this makes on multi-channel music is significant. Vocals are just more focused, without the need to cross the low frequencies over to the sub. I did feel that there was a bit of extra "chestiness" to Harrison's vocals, which was confirmed with my Audyssey graph. There was a noticeable hump in the frequency response from about 70Hz through 200Hz.
Due to the position of my TV rack, I could only keep about one foot of space from the back baffle of CSi A6 to my rear wall. Moving the speaker another foot away from the wall (or using Audyssey correction) almost completely eliminated the excess energy. A few other choice cuts on this disc helped demonstrate just how nicely the entire Polk system worked together. The sound moved seamlessly from speaker to speaker, which helped me just melt into the music. The A3 bookshelf speakers were a perfect tonal match for the A9 and A6, and maintained the full-bodied sound of their larger counterparts. Take a look at the in-room frequency response graph below. The A3's were extremely smooth through the midrange and treble, with just a few small dips around 250Hz and 700Hz (very likely room related).
Next up was the DVD-Audio disc of Talking Heads "Speaking In Tongues" (Rhino B000CCD0FI). The alternate version of "Burning Down the House" is one of the best demos of multi-channel sound you could ask for, and really allows the multi-layered sound of the Talking Heads to shine. Bass was tight and clean, the midrange was smooth, and it was easy to make out the subtle details in the treble as the sound bounced from speaker to speaker. This track gives the surround speakers a real workout, and the A3s were up to the task. In fact, the A3s could easily serve as a great 2-channel speaker or as the main speakers in a smaller surround setup.
Given that this was a system comprised of big speakers I felt that it was time to give them something really big to reproduce. In went the Blu-ray of Metallica's latest concert from Mexico City, "Orgullo, Pasión, Y Gloria." The Polks did not let me down. I've seen countless Metallica shows over the years and I will tell you that this is the closest to a live concert that I've ever experienced in my home. The 5.1 DTS-HD Master Audio soundtrack was amazing, capturing the raw power and energy the Metallica pours into every live performance. Lars Ulrich's bass was pitch-perfect and pummeling, the twin guitars of Hetfield and Hammett pushed forth a wave of sound in perfect synch, and Rob Trujillo's bass lines were easily discernable. Even James Hetfield's vocals sounded great, but they were obviously pitch-corrected (I wish he could remain on-key like this at a live show). I kept inching the volume up song by song until my SPL meter was showing about 110dB. Even at those insane levels, the Polk system remained smooth and in control with no audible distortion or extra harshness. If my ears could have taken it, I'm sure that there was at least another 5dB of output available.
The only thing I noticed was that the pyrotechnic explosions at the beginning of "One" didn't seem to have the same depth and butt-vibrating impact that I get with my reference sub. I'll chalk this up to the DSWPRO660wi's inability to produce the absolute lowest registers. Given the excellent bass performance of the A9 towers, I'd look for a sub that could go down cleanly to 20Hz. Also, if you are someone who likes things "cranked up to 11," make sure your amplifier is up to snuff. These speakers are capable of immense output levels, so I would try to feed at least 150 clean watts to each speaker. The big A9s and A6 seemed to really like the 550 watts provided by my Wyred4Sound amp.
Having proven their prowess with music, it was time to see how the RTi system fared with movie soundtracks. "Tron: Legacy" may not have been the greatest movie, but it sure has an incredible soundtrack. At the start of the light cycle battle, the announcer's voice echoed around the immense stadium with incredible realism, making me feel like I was sitting right in the middle of the monstrous arena. During the scene at the End of the Line club, the combination of the thumping Daft Punk soundtrack plus the great fight effects made for a grin-inducing audio feast. The lightjet scene later on was just icing on the audio cake. The Polk system handled the tremendous dynamics with ease and the surround field kept the same smooth transition from speaker to speaker that I experienced with surround music.
After the sheer power of the "Tron" soundtrack, I wanted to see how the Polk system handled more subtle effects. The introductory scene from "Master and Commander: The Far Side of the World" is a perfect example of how immersive a properly done soundtrack can be. The creaks and groans of the ship's timbers are so well done that you actually hear sounds coming from above you on a good system. The Polks were able to recreate this sense of height with ease, which makes the cannon blasts that come shortly afterward even more shocking. While these cannon blasts had great punch the depth of the blasts was still a little shallow due to the DSWPRO660wi's lack of extreme LFE response.
My Blu-ray copy of the "Lord of the Rings" extended edition arrived as I was writing this review so I put in "The Fellowship of the Ring" and went right to "The Bridge of Khazad-dûm." While one can debate the color-timing of this disc ad nauseum on various internet forums, there is absolutely nothing to criticize about the 6.1 DTS-HD Master Audio track. This scene has it all: incredibly deep bass, lots of surround sound effects, strong vocals, and some of the most dramatic scoring in film history. The Polk system did the track justice, excelling on all fronts. I had also swapped my reference Hsu VTF-3 MkII subwoofer back into the system and it proved to be a much better match. I now had bass response down to (and beneath) 20Hz, which made a big difference in the overall experience. The Hsu is slightly tighter sounding as well, which created an even more seamless blend of sound from the main speakers to the subwoofer. If it sounds like I'm being unduly harsh on the DSWPRO660wi, please don't take it as such. Considering the excellent musicality, compact dimensions, wireless capability, and $599.95 list price, the sub is a pretty good bargain if you have main speakers less capable in the bass range.
Conclusions About the Polk RTiA 5.1 Home Theater Speaker System
While I didn't feel that the DWSPRO660wi subwoofer was on par with the rest of the system, I was immensely impressed with the RTi A9 towers, CSi A6 center-channel, and RTi A3 surrounds. The slightly warm tone, overall clarity, and smoothness of the RTi system did justice to well-recorded sources and could even take the edge off of harsher-sounding music and movie sources without sacrificing too much life or detail. When you factor in the RTi system's ability to effortlessly deliver high-volume playback (with appropriate amp power), seamless blending of sound from speaker to speaker, excellent construction quality, beautiful real-wood veneers, and extremely reasonable price, you are left with a flat-out bargain of a full-range system. If you have a large room, appropriate amplifier power, and prefer naturally smooth sound the Polk RTi line could be just the ticket to music and movie nirvana. Highly recommended.