Since the first machines were introduced five years ago, DVD players have reached a remarkable level of performance—to the point where it's no challenge to find players for well under $200 that will satisfy most buyers. In fact, most video measurements tell us little about what we'll see from a given machine. The color quality is generally consistent from player to player, and video noise is almost always low. Artifacts are few (at least in interlaced mode), and are more often a function of the DVD and video display than the player.

But there are differences between DVD players, some of them not readily measurable. Some players perform better than others when downconverting anamorphic widescreen transfers for use on a standard 4:3 television. But this difference is meaningful only with the least expensive players. If you pay much more than $500 for a DVD player today, and you don't plan to use it with a widescreen set or a conventional set that has a 16:9 mode, you're probably spending too much money—unless you're buying it primarily for its audio features.

Two other characteristics that are visible but not readily measurable are deinterlacing artifacts on progressive-scan players and the so-called "chroma bug." We always look for artifacts—jagged edges or other, similar problems—on progressive-scan players. And the chroma bug is a glitch in the MPEG decoder that can cause streaks in areas of bright color. It is present in most players, though we have rarely found it annoying.

One aspect of player performance that can be measured and does seem to produce visible differences is the luminance (black and white) video frequency response. Table 1 shows the responses of a number of players, measured with a Philips PM 5662 waveform monitor in response to the luminance sweep (chapter 17-23) on the Video Essentials test DVD. The numbers were read from a plot on the face of the waveform monitor's CRT display, and so should be considered accurate only to about ±0.2dB.

Some interesting observations can be made about these results. In most cases, the interlaced frequency response is flatter than the progressive (but note that the Krell DVD Standard was much flatter in progressive mode). The most consistent players in this regard, and the flattest overall, were the Denon, Kenwood, Marantz, Pioneer, and Sony. We've read criticism elsewhere that some Pioneer players "ring." Ringing is a time-domain (impulse) problem that should show up as a sharp peak in the video frequency response. At least up to the 5.5MHz limit of our measurements, we saw no evidence of ringing in the Pioneer DV-47A or any of the other players. But players with very flat response, such as the Pioneer and Marantz, may well bring out the worst in DVDs with edge enhancement.

In my experience, players that roll off much more than about 2dB at 5.5MHz tend to produce slightly softer images than players with flatter response. Even losses of 1-2dB might be visible with finely detailed material, particularly on a larger display. But no player in the chart looked obviously soft when viewed by itself; it often took a direct comparison to a flatter player to see a difference, and even then, it didn't jump out.

Some viewers might even prefer a player with a slight high-frequency video rolloff. As noted in the review, with "flat" players like the Marantz and Pioneer, details such as the borders of faces could occasionally look a little edgy or enhanced on some DVDs—even when viewed on an affordable but very sharp, well-calibrated consumer display like the Hitachi 51SWX20B RPTV. However, both of these players provide flexible Sharpness controls to help minimize this effect.

Of course, none of this addresses those other issues: scaling quality on a progressive-scan player, chroma (including the chroma bug), and, of course, sound. The latter is a particular point of pride with players from high-end audio companies.

The measured differences between the progressive and interlaced video outputs of many of the players also suggest something else. It goes against conventional wisdom, but assuming you have a widescreen, HD-ready set or integrated HDTV, and the scaler in the set is relatively free of scaling artifacts and itself has a flat luminance response (two assumptions that won't always be the case), you might actually get a better picture by switching that shiny new progressive player to its interlaced mode. Don't automatically assume that the progressive mode will always give you the more detailed image.—TJN