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Hitachi 55HDM71

A 55-inch plasma monitor might not sound all that grand when several companies offer 60-inch models. Heck, one company has even shown a prototype 80-inch

Hitachi 55HDM71

Sep 1, 2004 12:00 PM,
By Jeff Sauer

Hitachi 55HDM71

A 55-inch plasma monitor might not sound all that grand when several companies offer 60-inch models. Heck, one company has even shown a prototype 80-inch panel at industry trade shows this year. But Hitachi’s new 55HDM71 does have one very grand feature that may bring it plenty of excitement: a price less than $10,000.

With an MSRP of $9995.99, Hitachi’s 55-inch plasma does more than break that important five-digit barrier. It also presents a significant street price discount of between 40 and 50 percent over all 60-inch panels on the market. (For example, Web pricing for the 55HDM71 is as low as $6,999, compared with well over $12,000 for the 60-inch panels.) Hitachi believes that when buyers look at the cost of those extra 5 diagonal inches (less than 2.5 inches taller), most will decide that the difference isn’t worth thousands of dollars. Those 55 inches might start to look pretty big.

The significant price break for 55 inches might also generate enough demand to make them actually worth building. Sure, the display industry has had a glimpse of that first 80-inch plasma, but only at a couple trade shows — and it will be another trade show where it’s seen next rather than at a store near you. The 80-inch panel is a prototype, even a manufacturing tour de force, but the company, Samsung, has no availability date for the product. There’s likely not going to be a strong-enough demand at the price the company would have to charge to make it worth putting into production any time soon. Even the makers of 60-inch plasma displays face decisions about using factory time to build larger panels instead of higher-volume smaller ones.


So what does Hitachi’s 55-inch panel offer? Aesthetically speaking, the 55HDM71 features an elegantly designed black bezel with silver details along the top and bottom. An optional silver-colored tabletop stand swivels to offer maximum flexibility for different rooms and groups. With more or less built-in wire ties, that stand also can be used to hide smartly any cabling coming off the unit’s rear panel.

FIG. 1: The ideal gray scale curve (white dotted line) and the unit’s actual measurements (yellow line).

That can be a lot of cables, too, because the 55HDM71 includes six inputs, five of which include dedicated stereo audio inputs. The data mode inputs one DVI and one 15-pin D-sub (also, there’s a 15-pin monitor output) that share a single audio input — in this case, an RCA stereo pair as well as a subwoofer out. The four AV inputs each take an RCA stereo pair for audio and an RCA composite video jack, and also either component or S-video as a higher-quality input option. Altogether there are two component, two S-video, and two RGB inputs split across the four AV inputs. The component/RGB physical connections are almost all through RCA jacks rather than BNCs. That will disappoint some potential users but please others depending on specific installation needs. The fourth AV input uses a SCART connection, though Hitachi includes an adapter for S-video, CVBS, and audio. For audio Hitachi includes stereo 12W (6ž) speaker outputs, with optional speakers.

To match its large size, the 55HDM71 has a native WXGA resolution of 1366 by 768 that can fully support 720p HDTV sources, as well as 1080i with minimal scaling. It can also handle computer inputs up to 1920 by 1080, and Hitachi does a fairly good, but not great, job of scaling images and keeping them sharp.

Hitachi’s image quality is good, too, especially when the panel inputs high-quality, high-resolution sources. That’s probably no surprise. However, there are a few caveats. The default settings for the 55HDM71 lean toward blue, and that affects the plasma’s overall color reproduction by pulling the depth of green down and moving cyan toward blue. On the other hand, red is very good, and yellow and magenta are pretty good, as well. My ColorFacts test equipment put blue at about 40 percent above ideal. That’s not particularly unusual, especially for computer source material. Indeed, higher (more blue) color temperatures are generally preferred for computer sources and bright conference rooms, and most display products with color temperature presets for “computer” do tend to accentuate blue. Unfortunately, Hitachi carries this blue bent through all of its presets for both AV and computer sources.

If you’re diligent, Hitachi’s menus do offer individual controls for R, G, and B amplitude and R, G, and B cutoff. These can get the color temperature just about wherever you’d like it. Digging into the menus also allows you to set advanced image features like black enhancement (mostly for video and film content), LTI and CTI luminance and chrominance sharpness filters, and noise reduction and manage individual primary and secondary colors to afford pretty easy and accurate calibration. Unfortunately, Hitachi does not allow you to save multiple settings.

Hitachi does not fare so well in its gray-scale range. Grays are greatly compressed and not particularly linear, as they should be. That ultimately hurts images because, though saturated red looks great, for example, there’s not much range for different brightness levels of red. The result is a lot more posterization across gradients than you might expect from a WXGA-resolution panel. Dark colors also tend to be noisy. In Fig. 1, the white dotted line shows the ideal gray-scale curve, and the yellow line shows the actual measurements from the 55HDM71. The nearly vertical line in the middle depicts a rapid rise from dark to bright rather than a more gradual, balanced gray scale that would ultimately yield a much greater range of colors.

To avert burn-in as much as possible, Hitachi smartly includes Screen Saver modes that, unlike computer screen savers, move (modulate) potentially static images around the screen by a few pixels at a time. You can also change the black bars beside 4:3 content to gray or use a Screen Wipe function to effectively refresh static images on a timed basis. There’s also an Inverse Image mode that displays a negative or reverse version of a static image to allow a panel to “burn” evenly if necessary. Another interesting public display feature is Hitachi’s ability to control as many as seven panels with seven distinct IDs through a single connection.


Overall, size and price are Hitachi’s major calling cards for the 55HDM71, and the combination makes for an attractive display. That should be especially true for public display installations, where big and bright with a low price matter and where quality needs to be good but perhaps not pristine. Still, at an MSRP less than $10,000, this 55-inch plasma display should have a large reception in several target markets.


Screen Size 55 inches diagonal

Screen Aspect 16:9

Display Resolution 1366 × 768

Displayable Colors 16.77 million colors

Pixel Pitch 0.9 mm × 0.9 mm

Horizontal Sync 31-62 kHz

Vertical Sync 50-80 Hz

Inputs (1) control terminal (RS-232C); (1) RGB1 (DVI-HDTV/HDCP); (1) D-sub 15 analog input/switchable to YpBpR (RGB2); (1) component YpBpR composite (AV1); (1) component YpBpR/composite/RGB (AV2); (1) S-video/composite (AV3); (1) S-video/composite (AV4)

Color System NTSC, PAL, PAL60, PAL-M, PAL-N, SECAM

Data Signals VGA, SVGA, XGA, WXGA, UXGA compressed

TV Scan Lines 480i, 576i, 480p, 576p, 1080i/50, 1080i/60, 720p

Audio Performance 12W plus 12W (6ž) amp, SRS TruBass surround, 4 sound modes

Power Supply 100-120V, 200-240V @ 50-60 Hz

Power Consumption 530W

Dimensions (H × W × D) 33¾ × 54⅜ × 41/16

Weight 142 lb.


Company: Hitachi;

Pros: Good image quality; helpful Screen Saver modes.

Cons: More posterization across gradients than usual from WXGA resolution.

Applications: Public display environments

Price: $9,995.99

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