PRODUCT REVIEW: OCTOBER 2008
Vizio SV420XVT LCD HDTV
Vizio continues to deliver great value in their HDTVs.
By now, you’ve probably all heard about Vizio, the low-price leader in LCD and plasma HDTVs. Over the past five years, Vizio has expanded its original base of Costco and Sam’s Club customers by adding showroom space at Sears and Circuit City, and is starting to give the better-known brands like Sony and Sharp a real run for their money.
The SV420VXT is one of their latest models, and comes equipped with all of the “must have” bells and whistles, including 1080p resolution, 120 Hz refresh for improved motion rendering, and four (yes, four!) HDMI inputs. Given how price-sensitive the TV market is these days, a value-priced 42-inch 1080p set this loaded will certainly attract attention.
Figure 1. Vizio’s SV420VXT is an eye-catcher.
OUT OF THE BOX
This is a sharp-looking HDTV, down to the piano black finish with below-screen speakers and a silver accent just above the low-profile stand. The SV420XVT should disprove the notion that lesser-known brands of TVs don’t have the same stylish appearance as their better-known competitors.
If you need lots of inputs, Vizio has you covered with four HDMI 1.3 jacks, two of which are on the side of the TV for gamers. There are also two component YPbPr video inputs with analog audio, two composite video jacks (who uses those anymore?), one S-video jack, and a 15-pin VGA jack for connecting to PCs.
There’s one RF connector that can be used to receive either unscrambled digital cable TV or terrestrial digital and analog TV programs. Vizio has also provided two audio outputs: One analog stereo with RCA jacks, and one optical (Toslink) connection.
The supplied remote control has a nice, simple layout with a snazzy menu navigator disk in the center. You can access different groups of inputs directly through four buttons at the top of the remote, or directly enter TV channels to hop around. Two oversize rocker switches control volume and channel up/down functions. The Menu and Exit buttons are diagonally opposite each other (an odd arrangement), flanked by the Last and Guide buttons.
Figure 2. All remote controls should have a layout this user-friendly.
MENUS AND OPERATION
You’ll want to set up the SV420XVT for best picture quality by first going into the Picture menu and taking the set out of the factory default Vivid mode, which is dazzlingly bright but will produce a screwed-up gamma curve. Vizio has programmed several Picture modes, including Standard, Movie, and Game and also four “ball” modes that look and measure almost identical (Football, Baseball, Basketball, and Golf).
In the SV420XVT’s Picture menu, you can adjust the backlight’s brightness, plus fiddle with brightness, contrast, color saturation and tint, and sharpness. For more precise calibration, you’ll want to go into the Advanced video menu, where you’ll find a three-level Smart Noise Reduction processor (for analog video), a four-step Color Enhancement menu (I’d suggest leaving this off entirely), an Advanced Adaptive Luma tweak (raises average picture levels, but screws up gamma at low levels), and an Enhanced Contrast Ratio (modulates the backlight to boost contrast).
The Color Temperature menu is also found here, and you can choose from Cool, Normal, or Warm settings. There’s also a Custom sub-menu that provides access to red, green, and blue drive for more precise calibration.
Vizio has also included a Smooth Motion processor (Off, Low, Medium, High) and a Real Cinema mode (Smooth, Precision). These not only work to clean up 3:2 pulldown artifacts, they can make 24-frame film content look exactly like 30-frame video. (It works so well that it’s downright spooky!) “Smooth” minimizes 24-frame judder, but may result in a “halo” artifact, while “Precision” enhances picture detail for movies.
Last but not least, there are four widescreen picture modes available from the menu and the remote. They are Normal, Wide, Panoramic, and Zoom. The last would be used to watch letterboxed widescreen programs on a 4:3 raster, while Panoramic is for anamorphic content from DVDs. HD programs automatically show up in the 16:9 format in any case.
The Audio menu has four equalization presets (Flat, Rock, Pop, Classic, Jazz) along with a five-band graphic equalizer. Here is where you can set the Toslink digital audio output mode (Dolby Digital or PCM), set the analog audio output to Fixed or Variable, and even use a digital audio delay to correct for latency (lip sync) issues – the first time I’ve seen that in a consumer HDTV.
Vizio has an optional wireless speaker kit for the SV420XVT, and you can configure several different ProLogic II sound fields to go with it. In addition, this system will provide Dolby Digital 5.1 playback automatically (it’s basically a wireless home theater in a box without the amplifier!).
PERFORMANCE AND VIDEO QUALITY
After calibration for best grayscale image in Custom mode (again, don’t use Vivid mode!), I measured brightness at 127 nits, using a full white test pattern. The factory presets blew that away by comparison, with brightness ranging from a high of 407 nits in Vivid mode to a low of 259 nits in Movie mode.
So why’d I dial brightness back so far? Because none of those factory picture presets gave me decent gamma response. Besides the s-curve gamma seen in Vivid mode, gamma curves in all other modes straightened out above 60 IRE, resulting in images more suitable for computer graphics than video or film. (127 nits equals 37 foot-Lamberts, which is plenty of headroom for peak whites.)
Figure 3. The SV420XVT’s gamma response in Custom mode is shown here.
Figure 4. It’s hard to track a given color temperature no matter what picture mode is in use.
Not surprisingly, contrast measurements were quite impressive at 317:1 ANSI (average) and 343:1 peak after calibration in Custom mode. Switching to Football mode yanked those numbers up to 587:1 and 662:1, respectively, but black levels suffered as a result.
Using my calibrated settings in Custom mode resulted in a 2.6 gamma, as seen in Figure 3. That’s a significant improvement over the factory gamma curves I measured in Vizio’s Vivid (S-curve, 2.1), Football (2.1), and even Movie (1.97) preset modes. 1.97 is nowhere near what a cinema gamma curve ought to be (between 2.5 and 2.6) because the SV420XVT is just running too hot out of the box.
The SV420VXT is an average performer when it comes to tracking a consistent color temperature, and there’s not a lot you can do about that as Vizio only provides one set of RGB drive adjustments — no low or gain tweaks. Figure 4 shows three different color temperature tracks, including my calibration, and in all three the range of color temperature measurements swings as much as 400 degrees from 20 IRE to 100 IRE.
Figure 5 shows the plotted color gamut for the SV420XVT, and it comes very close to hitting all six color coordinates in the BT.709 color space right on the nose. That’s very impressive performance for any LCD HDTV using a conventional cold-cathode fluorescent (CCFL) backlight and color filters. You’ll see an impressive display of colors as a result (and with that kind of accuracy, you can now understand why I suggest leaving the color enhancement circuitry turned off!)
Figure 5. As for color accuracy, it’s hard to get any closer than this!
For video quality tests, I first watched live HD broadcasts of NFL football on CBS (Steelers-Bengals, 1080i) and Fox (Giants-49ers, 720p). Colors were well saturated and accurate and there was excellent picture detail — so much that I could see occasional MPEG compression artifacts. Shadows, however, weren’t black so much as a washed-out gray.
Fast motion detail was better than I’ve seen on older LCD HDTVs. I was looking for any evidence of motion blur, and spotted it during kickoff returns and on tight close-ups with fast action. Vizio’s 120 Hz processing works about as well as any other late-model HDTV I’ve tested — it’s not perfect, but offers improvement. Put this set next to a plasma or DLP RPTV however, and you’ll see how far LCD motion detail processing still has to go.
Aside from that, Vizio’s black level and viewing angle performance just wasn’t up to snuff. You don’t have to sit very far off-axis before you see contrast start to flatten and black levels wash out. This isn’t quite as noticeable with mid- to high-luminance scenes, but anytime there are shadows or picture detail falling below about 30% gray, you’ll notice the screen washing out as you move your viewing location around.
How’s the SV420XVT’s 1080i processing? Pretty darn good, as shown by the Realta HQV Blu-ray Disc. This set aced both the Video Resolution and Film Resolution Loss Tests, with no evidence of “bobbing” seen — just full processing of odd and even fields with accurate motion interpolation.
The final image quality test was to spin up a BD copy of Mission Impossible III, which provided me with both black level and deinterlacing tests (Chapter 8) and color accuracy and contrast tests (Chapter 9). In the Vatican reception scenes, the deinterlacing was impressive while processing a native 1080i signal from the Samsung BD-P1200 player — not a hint of judder or twitter was seen. But the shots in the basement weren’t as detailed or contrasty due to black level problems.
On the other hand, the MI III attack sequence on the Chincoteague Bay Bridge Tunnel was simply spectacular, with eye-popping contrast and colors. In particular, the explosions, fireballs, and deep blue sky really stood out. Recall earlier that I mentioned the eerie effect produced by the Smooth Cinema processor? Turn it on here and in Chapter 8, and you’ll swear you’re watching live video — it’s that smooth (but it doesn’t look like film!)
CONCLUSIONS
Vizio’s SV420XVT is quite a performer. It’s got plenty of horsepower (maybe too much), accurate color, good contrast numbers, and a host of useful menu features including lip sync correction. The internal 480i and 1080i processing doesn’t cut corners, either.
What this HDTV lacks is greater control over picture calibration. Its gamma performance leaves a lot to be desired, its black levels are just not low enough, and its off-axis contrast performance is mediocre. The gamma problem could easily be fixed with improved calibration at the factory, but the black level and off-axis viewing issues will require improved LCD glass.
Power consumption: In a 6-hour test with standard widescreen and HD content, the SV420XVT consumed 153 watts on average while operating in Standard image mode.
