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Q&A # 360 - August 22, 2003
 

Staff

 

Q Tod DeBie, congrats on your Joe Kane/WM9 article. You shot the lights out! Wish I could have written that. Can Samsung bring this player (plays WM9 DVDs) in at $300? Of course I would pay more to be first on the block.

A Their current DVD player that delivers 720p and 1080i output through DVI is only $299, so we suspect that the WM9 player will also be in that range.

T

Q I have a 55" Mitsubishi 55807. I was wondering what the best viewing distance would be. I have about 7-8 feet distance from the screen. Is that too close to get an optimal picture?

A It really depends on whether you are watching 4:3, 16:9, or 2.35:1 images. I find that for widescreen movies, I like to sit closer than when just watching 4:3 stuff. In general, about 1.5 - 2.5 x the width of the screen is a good sitting distance, but actually it is just a preference thing, like some people at the theater enjoy being in the front row and others want to be in the back.

T

Q  I have noticed that flat-screen direct-view HDTV monitors (1080i native resolution) don't display DVDs (even from a progressive scan DVD player) very well. Why is that? Have I just seen a few poor models?

Here's what I've noticed:

1) CRT based displays that are not flat screen direct view (two examples: all RPTVs and the now discontinued RCA F38310) do a fantastic job of displaying a 480p signal.

2) Flat-screen direct-view HDTVs show a ton of upconversion artifacts when displaying a 480p signal, but do fine with a 1080i signal.

Here's what's strange: in both cases the 480p to 1080i conversion is in the analog domain, but flat screen monitors seem a lot worse (I know my Mitsubishi RPTV has a 960i mode for this, others like Toshiba RPTVs don't and don't have this kind of problem).

I know that using a DVD player like the Bravo D-1 or that new Samsung would solve this problem because the scaling is done in the digital domain, but these DVD players need a DVI connection (the Bravo can be connected with component, but your own tests say that it's not a good idea), which are not yet present on enough TVs.

Is there a solution for people who already own flat-screen direct-view HDTV monitors without DVI connections? (I'm thinking of my sister-in-law here.)

A The A/D and D/A converters are not what they should be in TVs yet. There are still some problems to be worked out. The worst seems to be in plasma displays for some reason. For a DVD player, the signal is digital, converted to analog, sent to the TV, converted to digital, upconverted, then converted back to analog for the actual display. There is where the problem lies. Too much back and forth. DVI eliminates that problem, because the image is not analog until it is sent to the pixels on the screen. For digital TVs without DVI inputs, there may be adapters for sources with DVI output down the road, but the signal will still be converted to analog before going to the TV. It is an injustice that early adopters get the shaft. It has happened to me a number of times.

T

Q I have a Parasound C2 processor, and my amps are the Aragon's 8008BB, ST, and X3. When I first bought these amps I was told by Aragon that they more than meet the specs for THX but now my question is, do these meet the specification's for THX ultra 2?

A Aragon builds their products with massive power supplies, so I suspect they will meet just about any THX type of specification.

T

Q Do you have a pointer to the THX Ultra2 speaker design specifications? I am mainly interested in knowing the changes from the earlier specs.

A The actual THX specs are confidential to THX and its licensees. THX will divulge on request what sort of things they spec but not what the figure/parameter, etc., actually is.

In the broad strokes therefore, with regards to Ultra2 speakers specifically, not much has changed really. The speakers still need to hit a given SPL within a certain distortion threshold and must do so with the minimum of dynamic compression, etc. They still need to have broad and even dispersion horizontally but limited and directional dispersion vertically. They still must be flat in their spectral response. All speakers must exhibit their own natural 2nd order rolloff at 80 Hz.

If anything, the output requirements (I believe) have been raised a tad.

The subwoofer spec has changed in that they must be anechoic flat to 20 Hz in order to accommodate larger and more varied spaces. Previously they needed to be anechoic flat to 35, albeit with a shallow (usually 2nd order) rolloff so that assumed room gain would take up the slack to 20 Hz.  In practice, this worked very well in my opinion (much better than ported designs which reach a little lower, but then disappear all together). It worked so well in fact that Ultra2 SSPs must include the "Boundary Compensation" option which is a fancy way of saying they make an Ultra2 sub behave like an Ultra, because in most rooms, room gain and an Ultra2 sub end up yielding way too much bass. Go figure.

Of course, the other new thing is the rear pair. They are to be a pair of direct radiating speakers, but this does not mean that direct radiators are suddenly THX's choice for any surround role. One has to understand that the rear pair in Ultra2 is controlled by ASA (Advanced Speaker Array) which treats the speakers each as one pole of a dipole speaker. ASA can be thought of as "varying" the dipole characteristic. In a classic THX Surround EX setup, dipoles are still called for at all surround locations.
 

T

Q I tested a Philips TV set with HDTV capability. One of its component inputs was specifically assigned for progressive scan and the other for interlaced signals. When inputting 480i through the progressive input, there is no image, and vice-versa. Could you please explain to me why? Even the Philips support couldn't give a reasonable explanation to this feature, which is annoying because when the progressive input is used, the TV locks into 16:9, and as a result non-anamorphic DVDs become stretched and distorted.

A With the progressive input, the deinterlacer is not in the circuit, so it is not passed through. With the interlaced input, it can't recognize the progressive signal. Philips knows this part, but don't know why they designed it that way. We found a similar thing with the BenQ PE8700 projector that we just reviewed, but its progressive input allows both interlaced and progressive signals. Interestingly, we found that an interlaced input gave the best picture, using two different DVD players.

T

Q Is the Denon DVD-1600 player still a good value, or are there other players that surpass it now?

A It is an excellent value in that it is at the end of its product life, so you should be able to get one at a reduced price.

T

Q When I am watching a DVD on my setup, say for example "Lord of the Rings", I can usually see what appears to be pixilation on the screen, in between the characters' lips as they speak, in the black area inside their mouths. It can best be described as horizontal lines of color, nearly matching what should be there. It is very distracting, and I find myself watching only their lips throughout the movie to analyze the artifacts . . . and I don't see any of these artifacts on other parts of the screen. Now I am aware of the incorrect chroma upsampling present in many DVD players, probably in mine too, but could it be something else? Can it be that the compression that is done to the original video source has such a limited dynamic range that the darker blacks cannot be realistically reproduced?  It almost looks like that section of the video is not really progressive scan. If you think this is the faulty MPEG decoder in the DVD player, then what current models do you recommend that have been fixed? As you can see below, my system is on a budget, so I would be looking for a low-cost replacement DVD player.

Samsung TXM3096-WHF, 30" HDTV
Yamaha HTR-5560, 6.1 receiver
Toshiba SD-3750, progressive scan DVD player
(AR component video cables from DVD, to receiver, to HDTV)

A It is funny to think back when we watched movies on VHS tape. The picture was garbage, but we were not obsessed with it because we couldn't do anything about it. Now, with digital movies, we worry about every pixel on the screen, to the point of not enjoying ourselves. We all do it, I guess. Anyway, this sounds like one of the chroma problems we described, since you see horizontal lines as part of the artifact. Sometimes the artifacts are just more noticeable in dark areas, but they occur everywhere. Perhaps the D/A and A/D that goes on from player to screen might aggravate it. I am anticipating that DVI from player to TV will help with many of the artifacts that plague us now. The Samsung DVI setup (DVD player and DLP TV) that I saw recently just blew me away, so I have great hopes for it.

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