(Reprinted from issue 62 of UHF Magazine. To purchase the issue, click here. Or click here to subscribe to UHF)
No, of course not all DVD players are alike. And the included features can make a major difference. Here's why.
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If DVD players appear to be much alike, that's little surprise. So do CD players. However we know -- though the flat earth magazines deny -- that they vary enormously in the way they sound. And that's despite the fact that the transports most often used (Philips, Sony or Teac) and the chipsets (Burr-Brown, Crystal Semiconductors, Analog Devices) are available to any manufacturer.
When it comes to features, DVD manufacturers seem to be playing follow the leader, and indeed "special" features are percolating down from expensive models to ones that are sold in discount department stores. Let's see what the differences are, and what features are useful.
Built-in surround sound decoder
Don't go by the Dolby Digital and DTS logos on the front panel. Those indicate only that discs made with these encoding systems can be played, though not necessarily with surround sound. To spot this feature look at the rear. There will be six analog outputs, including ones for the centre channel, the rear and the subwoofer.
How much weight should you give to the presence of a decoder? It's useful if you are adding a DVD player to a high end stereo system, if you won't be able to afford a good outboard decoder right away, and if you want surround sound now anyway. But note that the decoder seems to add almost nothing to the player's price, and you can guess that the sound will be of only casual interest.
There's another reason for the processor to be outside the player: the ability to process sound that does not originate in the player. This includes broadcast TV (mainly from satellite) with Dolby Digital sound, and also the many sources -- including videotapes -- with Dolby Surround sound, which can benefit from Pro Logic processing.
S-Video output
This uses a round multipin connector rather than an RCA plug, thus allowing luminance and color to be sent separately. Don't even consider a player without this, even if your present TV doesn't have an SV input. You may not have that TV forever.
Component video output
Instead of being channeled through one or two cables, component video is separated into three distinct signals: Y (luminance), Pb (yellow-blue chrominance information) and Pr (yellow-red chrominance). Though this setup will cost you extra in cables (and if you want quality you shouldn't use any cables that may come free with the player) it's worth it. However most TV sets in common use today do not have component inputs. It's one more reason to upgrade.
But be warned: the presence of a component output does not indicate that the next feature is also included.
Progressive output
This is different from the usual interlaced output. In the North American NTSC system, a picture is made up of 30 images per second, which is itself made up of two frames: one with odd-numbered scan lines and one with even-numbered lines. In Europe and other PAL or SECAM areas, 25 frames per second are delivered with 50 frames. Interlacing reduces perceptible flicker, but it also reduces image resolution. Big time.
Progressive video delivers the lines in first-to-last order. This reduces a number of video artifacts that make video look different from film, and which keep reminding you that you are watching TV. The presence of scanning lines is one of those TV artifacts. Progressive scan can make the lines all but vanish.
Unfortunately, common TV sets are hardwired for interlacing. Early progressive video systems (such as the excellent Faroudja line doublers and quadruplers) could be used only with data grade projectors, actually designed for use with computers. That has changed. Any "digital-ready" set (i.e. a TV that will accept a set-top box) is already designed to show more than 525 (or 625) lines. These sets are becoming more and more common, and not long from now all sets will be digital-ready.
Your next DVD player should have this, but the process of assembling a deinterlaced picture requires considerable horsepower. You can expect low-cost players to do it poorly. If price is a consideration, you may opt to buy cheap, and then dump the player when you're ready for your next TV set.
The other thing we can tell you about progressive scan (in NTSC land it's called 480p, because only 480 of the 525 video lines are used for the actual image) is that not all equipment does it equally well. DVD's include a "flag" to tell the player whether the source is video (interlaced at the source) or film (24 frames per second). But the flag is often set wrong. It's what the circuit does with a wrong flag that separates truly great equipment from mass market
When it comes to features, DVD manufacturers seem to be playing follow the leader, and indeed "special" features are percolating down from expensive models to ones that are sold in discount department stores. Let's see what the differences are, and what features are useful.
Built-in surround sound decoder
Don't go by the Dolby Digital and DTS logos on the front panel. Those indicate only that discs made with these encoding systems can be played, though not necessarily with surround sound. To spot this feature look at the rear. There will be six analog outputs, including ones for the centre channel, the rear and the subwoofer.
How much weight should you give to the presence of a decoder? It's useful if you are adding a DVD player to a high end stereo system, if you won't be able to afford a good outboard decoder right away, and if you want surround sound now anyway. But note that the decoder seems to add almost nothing to the player's price, and you can guess that the sound will be of only casual interest.
There's another reason for the processor to be outside the player: the ability to process sound that does not originate in the player. This includes broadcast TV (mainly from satellite) with Dolby Digital sound, and also the many sources -- including videotapes -- with Dolby Surround sound, which can benefit from Pro Logic processing.
S-Video output
This uses a round multipin connector rather than an RCA plug, thus allowing luminance and color to be sent separately. Don't even consider a player without this, even if your present TV doesn't have an SV input. You may not have that TV forever.
Component video output
Instead of being channeled through one or two cables, component video is separated into three distinct signals: Y (luminance), Pb (yellow-blue chrominance information) and Pr (yellow-red chrominance). Though this setup will cost you extra in cables (and if you want quality you shouldn't use any cables that may come free with the player) it's worth it. However most TV sets in common use today do not have component inputs. It's one more reason to upgrade.
But be warned: the presence of a component output does not indicate that the next feature is also included.
Progressive output
This is different from the usual interlaced output. In the North American NTSC system, a picture is made up of 30 images per second, which is itself made up of two frames: one with odd-numbered scan lines and one with even-numbered lines. In Europe and other PAL or SECAM areas, 25 frames per second are delivered with 50 frames. Interlacing reduces perceptible flicker, but it also reduces image resolution. Big time.
Progressive video delivers the lines in first-to-last order. This reduces a number of video artifacts that make video look different from film, and which keep reminding you that you are watching TV. The presence of scanning lines is one of those TV artifacts. Progressive scan can make the lines all but vanish.
Unfortunately, common TV sets are hardwired for interlacing. Early progressive video systems (such as the excellent Faroudja line doublers and quadruplers) could be used only with data grade projectors, actually designed for use with computers. That has changed. Any "digital-ready" set (i.e. a TV that will accept a set-top box) is already designed to show more than 525 (or 625) lines. These sets are becoming more and more common, and not long from now all sets will be digital-ready.
Your next DVD player should have this, but the process of assembling a deinterlaced picture requires considerable horsepower. You can expect low-cost players to do it poorly. If price is a consideration, you may opt to buy cheap, and then dump the player when you're ready for your next TV set.
The other thing we can tell you about progressive scan (in NTSC land it's called 480p, because only 480 of the 525 video lines are used for the actual image) is that not all equipment does it equally well. DVD's include a "flag" to tell the player whether the source is video (interlaced at the source) or film (24 frames per second). But the flag is often set wrong. It's what the circuit does with a wrong flag that separates truly great equipment from mass market
(This is actually only a brief excerpt from the full article. There are other aspects to DVD players you should watch for. You'll want to see the three spectacular off-screen color photos showing a detail of the same scene from VHS, from DVD, and from DVD progressive. You'll also read about the market pressures threatening to derail HDTV. For the entire article, just order issue 62 at our secure server.)
Complete articles from this issue:
Vecteur I-4 integrated amplifier, Antique Sound Lab passive preamp, State of the Art
Excerpted articles from this issue:
Copy Right!, DVD for Your Future, Vecteur L-4 player, Musical Fidelity Nu-Vista amplifier, Moon Attraction processor, Creek OBH-12, Two Interconnects, Antique Sound Lab amplifier