NHT Evolution T6 Tower surround speaker system Page 3
After some tweaking of the X1 crossover's phase and boundary equalization controls (the manual provides excellent guidance on how to do this), the bass from the B6 subs was impressively powerful and deep with any music I threw at it. From percussion to organ to synthesized bass, the B6s' bottom end compared favorably to the performance of a single Revel B15 subwoofer. But the NHTs' four 12-inch drivers did no better than the Revel's single 15-incher. This was probably due as much to positioning (in the corner for the Revel, well out into the room for the NHTs) and equalization flexibility (the Revel's parametric equalizers provide greater control than the X1's Boundary and Phase controls) as to any inherent performance differences. The Revel did seem to go subtly deeper and play louder, but these advantages weren't particularly significant on music.
With the center and surrounds fired up and the best DVD film soundtracks rolling, the NHTs filled my listening room with some of the best movie sound I've heard. I had the NHTs in my system for two months and listened to dozens of films. The sound was as varied as the soundtracks themselves, the NHTs themselves sounding exceptionally neutral.
The new, extended edition of The Lord of the Rings: The Fellowship of the Ring was little short of magical. From the gripping scenes in the mines of Moria as the Fellowship flees the Balrog, to the delicate spaciousness of the choral music that brings the Lothlórien sequence alive, I had no complaints. There was sometimes a trace of excess crispness (but not hardness) to the sound on the loudest passages with the Dolby Digital track, but this was smoothed out with the DTS version. On the other hand, Dolby Digital sounded more spacious and transparent on the subtlest details.
The dialogue from the M6 center-channel displayed a trace more coloration than I've heard on a few of the more expensive center-channels I've had in my system. But the inherent dialogue coloration of soundtracks in general is far more significant than any residual coloration in the M6. I did find that the Boundary switch on the M6 center-channel speaker worked best in my system when set to the same position as the other channels: "0" for flat response. Despite the speaker's being less than 2 feet from the floor, setting the switch to "1" resulted in too much loss of vocal warmth. Your situation may be different.
The two B6 subwoofers produced outstanding bass power and extension, and the X1's controls provided a useful range of adjustments for getting the best out of the system. I listened to the entire 10 hours of Band of Brothers on the NHT system, and, apart from the exceptionally natural sound overall, what I remember most is how believable the explosions and artillery shells sounded. Not that I've ever been under heavy bombardment myself, but it felt as if the sound mixers made a sincere attempt to produce serious but natural bass, without typical action-movie exaggeration. Rather than making the low-end impact less impressive, it actually made it scarier. I felt as if I was actually there, rather than being constantly reminded that this was a Hollywood simulation of the real thing.
But a full-range system such as the T6 can rarely be positioned to provide both the best image and the best bass—particularly with a projection screen constraining the setup. So while the two B6 subs extended down to at least 25Hz, they couldn't quite match the sheer power and authority of the Revel B15 sitting in the corner. The two subwoofer systems were equivalent on most material, but the Revel sounded more powerful in the very lowest bass. This was nowhere more evident than in the opening scenes in Star Wars: Episode II—Attack of the Clones, as Senator Amidala's transport makes its approach. The B15 shook the floor more convincingly than the B6s.
Oddly, the bass was sometimes more impressive with only one B6 operating, but the response with two subs was clearly smoother, as confirmed by in-room measurements. While the response linearity was better with two subs working together, it was no flatter than the response of the single corner-positioned B15. You shouldn't generalize from this; the Revel's three parametric equalizers were clearly a big help in optimizing its in-room performance.
The audible differences between the two woofer systems were evident only in a direct A/B comparison. Nevertheless, they clearly indicated the advantages of subwoofers that can be positioned independently of the main speakers, allowing the bass performance to be optimized without compromising the system's imaging. With a system such as the T6 Tower, you gain a space advantage (separate subs use more floor space), but you lose out in positioning options—even with the X1 crossover's flexible controls, which do help get the best out of the system.
I didn't try the more conventional Evolution subs NHT makes available, the U1 and U2, but I venture that they might offer useful setup advantages—provided you have the space to accommodate them. Two U1 or U2 subs could be placed together or separately, in corners or along walls. Experiments conducted by others, including Todd Welti of Harman International (see his paper "How Many Subwoofers are Enough?" presented at the 112th AES Convention in Munich, Germany, Convention Paper 5602), suggest that two subs, placed against opposite walls halfway along a room's length or width, provide real advantages in getting the smoothest bass response at different listening positions.
My impressions of the NHT Evolution T6 Tower System can be summed up in a single word: Wow. And the fact that you can build up this system in stages—perhaps using the M6s at first with an existing subwoofer—makes it even more attractive.
What impressed me the most about the Evolution T6 System was its evenhandedness. Equally adept with music and soundtracks, it revealed flaws in bad recordings but never blew those flaws out of proportion. Most of the time, it "disappeared" and did not call attention to itself—except when I began to notice how good my music sounded, and how many good-sounding films there are on DVD.