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Q&A # 130 - August 5, 1999
Staff
Q My question relates to a comment made in Q&A 129 about the Sony Wega televisions having a "squeeze" feature that enhances widescreen playback on a 4:3 television. I was wondering if you could provide a little more detail on this feature and if it is available in the current production line of Wega sets.
A I knew when I mentioned the squeeze feature that we would get some mail on it. :-) OK, 16x9 enhanced material is squeezed and when viewed back on a 4x3 set everything is tall and skinny. A 16x9 set can unsqueeze or stretch the width of the image to fill the entire screen. Up until now, if you owned a 4x3 set you had a couple of choices: 1. You could let your DVD player down convert the image to standard letterbox. Early DVD players were not very good at doing this, and some artifacts were introduced. 2. You could watch the show with people tall and skinny (not really an option). 3. You could manually squeeze down the image in service mode on some TVs (this could potentially damage the TV). In Japan and Europe, where 16x9 sets are the norm, they have a feature on 4x3 sets to add the black bars to the top and bottom of the image, without downconverting the image, by simply squeezing the height. You can see an example of this by looking at your computer monitor. By going to the setup menu, change the height of the image. The feature on the upcoming Sony Wega's is a simple button to do what is already available on our computer monitors. You just want to be sure you do not squeeze normal TV images.
Q Are the new generation of single chip DLP projectors now suitable for upper end home theaters? I am thinking specifically about the Runco VX1. I would be willing to give up a little bit of performance in black level for more flexibility in room light conditions, especially when watching non-movie material such as a sporting event.
A Three-chip DLPs have better color fidelity than any CRT available. They are able to accomplish this because they have one chip dedicated to each of the three primary colors (red, green, and blue). One-chip DLPs have to use a color wheel that spins, and they are not always as clean as the three-chip design. In the recent past, reds have been more orange than red. This technology is advancing extremely fast, and today's one-chippers are much better than those just a year ago. To help with the black level problem, get a bigger screen. With CRTs, we were limited to a smaller screen. Seven feet wide was the recommendation for a 7" CRT projector. With DLP, you best start with 9' or 10' screen. With CRT, you also need a higher gain screen, and 1.3 was minimum. It had the least amount of hot spotting and the best white field but also provided the least bright image. Higher gain screens produce a brighter image but have poor white field uniformity (sitting at the side is no good). With DLP you can get a 1.0 gain screen and still have a brighter image than any CRT based theater. DLP is a fixed resolution system, currently having a 4x3 aspect ratio and running at 1024x768. We should start seeing 16x9 panels soon and also higher resolutions. Currently DLP cannot fully resolve all of the detail in HDTV's 1080i (1920x1080). Also, any image you feed into a DLP will get scaled to its native resolution. So if you have a DLP that runs at 1024x768, you would get the best image by mating a scan converter to it that can output a 1024x768 picture. The new Faroudja DVP-3000 is one of a few that can do this. I believe the Deuce, Dwin TranScanner, Runco, and Snell & Wilcox products can all do a better job than the internal scaler that DLP can provide. I have only had one look at the Runco and that was for less than 1 hour. It was on a 13' wide 1.0 gain screen. It was a bright colorful image. Spending that much money on a product deserves lots of evaluation before you purchase. Find a local dealer and bring lots of software to watch on it. Bring a copy of Avia or VE with you and make sure it is set up properly. Just because this will be in a high performance show room does not guarantee it will be se tup accurately. Don't make a decision in just one day either. See it over several days. Compare it to an equally priced CRT using the same software and scan converter.
Q A ridiculous question, please don't laugh, If you rate the sound quality of complete audio system by 100% total, what is most influential in terms of overall sound quality, i.e., 40% power amp, 30% preamp? 20% speakers and 10% cables?
A I would say 20% preamplifier, 20% power amplifier, 50% speakers, and 10% cables. Of course, that leaves you with 0% for the source, which makes for a very quiet evening.
Q I went by a TV store today, and they had some HDTVs there, mostly Mitsubishi. The images didn't look very good. I suppose it was all 480p. DirectTV is supposed to have HDTV signals on satellite by October. It's all over the air right now. No cable, no satellite. The large Mits was $9,000 not including the decoder box. That makes it about $14,000 and I don't know if it will do 720p. No wonder they are not selling very many.
A The best way to enjoy HDTV for the next few years will be UHF antenna. DirecTV is not the same resolution. It is lower to push more channels. So, while UHF gets 1920x1080, DSS does not. Washington State has the most advanced HDTV system in the country, but the consumers there are also the least educated about it. Mits is also releasing several HDTV 4x3 models to go along with the true 16x9 ones. This is just going to confuse the market. To fully resolve 1920x1080, you need a CRT projector with 9" guns. Most rear projectors have 7" guns, but some of the new ones do have 9" guns. You can still enjoy, but not fully resolve, the signal.Q Congratulations on your resolution essay. It should help readers better understand resolution numbers. However, the postscript confuses the maximal resolution of some source materials with the DVD medium's actual maximal TVL resolution. On the AVIA test disc, we bypass the head end are able to put details as fine as every other pixel (540 TVL) in the resolution test patterns. The 480 TVL limitation is not of the DVD recording medium, and I am afraid your postscript will confuse people in this regard. The DVD max TVL resolution is 540, not the artificially lowered 480. (Guy Kuo)
A Guy is the Author of the Avia test DVD. What he is saying is that the max of D1 is 480 TVL (6 MHz), but that is not really the max of DVD, which is 540 TVL (6.75 MHz). So, the Joe Kane Disc (VE) only goes to 480 TVL because it was transferred from D1 (all movies are). Guy transferred Avia directly from the digital domain and bypassed D1.Also, Brian Florian answers:
Thank you for your kind comments. It was not without deliberation that the final text was drawn to include the 480 figure. Attempting to present a simplification of the topic is in and of itself a challenge. In referring to the respected writings of Joe Kane, DVD's horizontal figure of 480 has been used. Although the writings using the figure are dated, they are still quoted for the original reason: the level of ubiquitous mastering facilities. An effort to "aquaint" the reader with the variety of figures they are likely to have heard may very well have been beyond the scope of my simplification. Your input is appreciated and will be recalled for future compositions.
Q I am going to upgrade my present five-year old Mitsubishi VS-1202 7" CRT Projector. This projector has a relatively low light output of only 700 lumens at 10% peak white and a fixed horizontal scan frequency of 15.75 kHz. I am now considering to choose the most cost effective projector from three pre-selected 7" CRT products such as BarcoVision 708MM, BarcoData 708, and Sony VPH-D50QM for my 100" home threater. The above three projectors are all equipped with line doubler kit. When viewing the demonstration in the showrooms, the video quality from these projectors are very good (compare to my present projector) and difficult to differentiate which one is better. However, when comparing the technical specifications of the projectors, I am confused by some of the technical terms and figures such as light output, scan frequencies, RGB Bandwidth, resolution, etc. The quoted values from each of the models are as below:
|-------------------+-------------------+------------------->
| | BarcoVision 708MM | Barco Data 708 |
|-------------------+-------------------+------------------->
>-------------------|
| Sony VPH-D50QM |
>-------------------|
|-------------------+-------------------+------------------->
|Light Output |Economy 130 ANSI lm|Economy 130 ANSI lm|
|-------------------+-------------------+------------------->
>-------------------|
| 160 ANSI lm |
|(64kHz:50Hz, 6500K)|
>-------------------|
|-------------------+-------------------+------------------->
| | Normal 170 | Normal 170 |
| | ANSI lm | ANSI lm |
|-------------------+-------------------+------------------->
>-------------------|
| 130 ANSI lm |
|(15kHz:60Hz, 6500K)|
>-------------------|
|-------------------+-------------------+------------------->
| | Boost 200 |Boost 200 |
| | ANSI lm | ANSI lm |
|-------------------+-------------------+------------------->
>-------------------|
| All White 200lm |
>-------------------|
|-------------------+-------------------+------------------->
| | 10% peak white | 10% peak white |
| | 1,100 lm | 1,100 lm |
|-------------------+-------------------+------------------->
>-------------------|
|Peak white 800 lm |
>-------------------|
|-------------------+-------------------+------------------->
|Scan Frequency | | |
|-------------------+-------------------+------------------->
>-------------------|
| |
>-------------------|
|-------------------+-------------------+------------------->
|-Horizontal | 15 - 50 kHz | 15 - 69 kHz |
|-------------------+-------------------+------------------->
>-------------------|
| 15 - 64 kHz |
>-------------------|
|-------------------+-------------------+------------------->
|-Vertical | 37 - 210 Hz | 37 - 210 Hz |
|-------------------+-------------------+------------------->
>-------------------|
| 38 - 150 Hz |
>-------------------|
|-------------------+-------------------+------------------->
| | | |
|-------------------+-------------------+------------------->
>-------------------|
| |
>-------------------|
|-------------------+-------------------+------------------->
|RGB Bandwidth | 45 MHz (-3dB) | 75 MHz (-3dB) |
|-------------------+-------------------+------------------->
>-------------------|
| 75 MHz (-3dB) |
>-------------------|
|-------------------+-------------------+------------------->
| | | |
|-------------------+-------------------+------------------->
>-------------------|
| |
>-------------------|
|-------------------+-------------------+------------------->
|Resolution | 10 lp/mm | 10 lp/mm |
|-------------------+-------------------+------------------->
>-------------------|
| 700 TV lines |
| (video) |
>-------------------|
|-------------------+-------------------+------------------->
| | 1024 x 768 | 1280 x 1024 |
| | pixels/60 Hz | pixels/60 Hz |
|-------------------+-------------------+------------------->
>-------------------|
| 1000 TV lines |
| (HDTV) |
>-------------------|
|-------------------+-------------------+------------------->
| | | |
|-------------------+-------------------+------------------->
>-------------------|
| 1280 x 1024 (RGB |
| 60Hz) |
>-------------------|
Can you explain the implications of the above technical values in relation to possible effects on the video quality and the significance of each other? I recall from Q&A # 28 (Sep 9, 1997) that HDTV requires the projector to have 4 times the standard NTSC horizontal frequency of 15.75kHz (i.e. 63 kHz). I wonder whether the BarcoVision 708MM is compatible with the HDTV standard (Barco's literature claims it is). The cost of the BarcoVision 708MM and Sony VPH-D50QM are comparable, while the BarcoData 708 is 10% more expensive. The projector is mainly used for films/concerts from DVD or LD, and I do not need it for any computer connection or application. I do not want to spend more money on some unnecessary features or purely specification figures that cannot be differentiated by our eyes. Therefore, I should be pleased if you could recommend the most cost effective projector to me based on your experience and professional knowledge on the technical specifications/figures. In addition to the above, I am preparing to purchase a new Stewart SR-1 Electri Screen for my home theater. The choice of the screen surface can be either Studiotek 130 (developed by ISF) or Ultramatte 150. What is your opinion on the above screen, and which screen surface is your recommended option if my projector is going to be hung on the ceiling?
A Lots of good questions. First, the internal line doublers in all those projectors are not as good as the new, inexpensive, iScan Plus from DVDO. For $599, it makes a huge difference over the built-in ones. Second, video, like the concerts you watch, will not look as good when doubled like they currently do on your NTSC projector. This is why, at trade shows, they never show you video based material, only film. It is something you learn to live with. Just wanted to make that clear. It takes a 9" CRT to fully resolve the pixel detail for 1080i, but you can still watch and enjoy it with a 7" CRT. This is how I will be enjoying it for the next few years. Along with the projectors you mentioned, you might also consider the Dwin HD-700, which is in the same price range but has no fan noise. The projector must be able to scan at around 33.75 kHz for 1080 and 45 kHz for 720p. All three projectors you listed and the Dwin will be able to handle that. One thing you will need to find out is the horizontal retrace time. 1080i requires 3.77 �Sec (microseconds), and 720 requires 4.98 �Sec. They are lacking in the resolution department to fully resolve HDTV, but like I said above, you will still notice a great improvement. 1080i is capable of 1920x1280 (1707 TV lines), and 720p is capable of 1280x720 (1138 TV lines) from terrestrial broadcasts (rooftop antenna). HDTV from a satellite provider like DSS is a lower resolution signal. Stewart makes some very nice screens. The lower the gain, the better white field uniformity you will have. This means that when looking at a white field you should see white, but in reality you will see it red tinted on one side and blue on the other. This is because you have 3 CRTs. A lower gain screen will produce the best results on this but will not reflect as much light. It is a tradeoff, but if you can totally control room lighting and have it pitch black, this includes the walls, ceiling, and floor in the area around the screen, go for 1.3, as it is the best. If you need more light, go for the higher gain screen.
Q I bought the unit recently after coming across your review of the meridian 518. Have you found a dither curve setting that works best? I found curve D sounds best. My settings are 16 bits in and 20C out. Emphasis autosensing is selected as is the default setting for resolution enhancement usage. Any other updated thoughts on this unit would be most welcomed.
A I use curve D as well, with 16 in and x out. I have it connected to the 565, so I use 22c out. I also have the clip display turned on. I use emphasis only on music and turn it off if the clip warning is displayed.
Q 1. If you accidentally connect the center channel speaker with the wires reversed, will this cause voices not to match the actors as they speak (misaligned)? 2. Will we ever see Jurassic Park, The Lost World, and the Star Wars Trilogy on DVD, either DD or DTS?
A Reversing the speaker connections for the center won't affect the alignment between the image and sound, but it could affect the soundstage across the front during sound effects that come from all three speakers. However, it would probably be a minor thing, and not noticeable. I am sure we will see all the movies you mentioned on DVD. There is too much money to be made not to put them on this wonderful new format. However, it is all politics for these particular films.
� Copyright 1999 Secrets of Home Theater & High Fidelity
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