Surround Sound Speaker Systems
- Written by Tyler Stripko
- Published on 02 December 2011
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.