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Discussion Starter · #1 ·
I hope this isn't blindingly obvious, because I'm going to feel like a total idiot if it is, but:


I saw a post by brvheart over on the HDTV local info forum. He seems to work with cable installation in some fashion, and he said when hooking up Comcast's cable + HDTV package, (Motorola 5100 box?), he hooks up the component and the coax, and tells the customer to switch to coax when watching SD TV.


Now, I should preface this by saying that I saw the SD channels on my friend's HDTV hooked up through the component inputs, and it was pretty bad. But I suggested this technique to him a few hours ago, and he just tried it.


The result? Through coax or composite, his SD channels had a phenomenal jump up in quality, with composite looking better than coax. He has not tried SVideo yet, but probably will tonight. I can relate his findings as soon as I hear back from him if anyone is interested.


By itself, this is great news, and this is the first time I've heard this. Everyone has suggested that you want to use the best connection available to you when watching SD so that the picture is as good as possible -- to me, this means that component inputs should be the best choice for SD.... Clearly there is a disconnect here.


My assumption is that there are filters on the TVs to handle the normal kind of noise that's present in SD broadcasts, but the filter is disabled for composite.


I partly just wanted to make this info a little more available since it's the first time I'd heard it. However, I have several related questions now:


Does anyone have more insight into this?

Which inputs would be filtered, and is this standard?

My friend has a CRT RP, but I'm getting the Panny 50" LCD RP on Sunday (woohoo!), and I'm wondering if anyone has tried this on their PT-50LC13?

Is there any way to control this filtering that anyone has found?
 

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Best connection depends on the nature of the original source material. The signal on the analog channels is composite, so any other output is going to involve comb filtering, and/or deinterlacing, scaling etc. In this case, the 5100 on component out is upconverting the SD to 720p/1080i; it's not too surprising that the TV does a better job of this than the cheaper processing in the STB.


I would expect on the digital SD channels for the S-video to be slightly better than composite. But would guess the opposite for the analog channels.
 

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Discussion Starter · #3 ·
Well, I got my Panny 50" LCD today. :D


I've got my TiVo hooked up to it for normal TV watching, and between the SVideo and Composite, I think the Composite looks a little better. Again, not what I would have expected, but it sure seems to be true. I guess as you go down on the food chain of connection type, the amount of filtering goes up to compensate, and noise goes down! (Though I expect coax would be worse than composite, of course.)


Anyone else have similar/contrary experiences?
 

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Slightly OT, since my DLP isn't delivered yet, but I tried this same thing with the 5100 on my 36XBR400 and had a similar effect.


Analog cable channels that were ok->horrible before now pretty much all are ok. The loss of color depth (which wasn't there anyway I suspect) is made up for by a "smoothing over" of the mpeg-type noise. Having to switch inputs to watch HD/Digital channels is kind of a pain but it's worth it.


Overall, I'd say it looks more like a "average" tube using the composite with the analog channels, rather than a digital display being fed a bad signal. I'll write again when my DLP comes in and I see if the same trick helps.
 

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Discussion Starter · #6 ·
Okay, yes, I admit after a couple beers the PQ did look better, so I switched the inputs around again just to be sure. I'm sure.


But yeah, it looks almost reasonable for SD TV now. Better than I was expecting. I'm soooo happy. :D
 

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Quote:
Anyone else have similar/contrary experiences?
Every day!


Sorry, I just had to chime in on this one. I would say that 95% of TV's I work with see improved performance on SD when not using component connections on the DCT 5100. On the remaining 5%, the SD performance over component looks no better, no worse. Usually these are the Direct View sets.


You've got to keep in mind that the SD picture is simply not high resolution or high quality either for that matter. So the difference between different quality cables will not necessarily result in better picture. You will notice different aspects to the picture when using composite vs S-video, etc. Personally, on my own setup, I find that composite gives me the best performance on SD channels over S-video. But I prefer S-video over composite on other devices such as game consoles, etc.


Cable has really not changed much at all over the decades now until HD. This stuff has always been designed to be used with coax cable. You can pretty much forget about digital cable. That's done for quantity, not quality.
 

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On the 5100 you should also experiment with the "4:3 override" 480i setting in the setup menu (power off, hit menu), which turns off the upconversion to 720p/1080i on the component output for the standard channels.
 

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FWIW - I am using a Zenith SAT520 STB with the Panny 50LC13 and I run HD and SD thru the STB @ 720P via DVI and while the SD stuff doesn't look that great, it isn't too bad either. I don't switch the STB between SD and HD or DVI and S-Video since it is a pain in the a** to switch inputs on these two components. You have to answer a question on the menu and physically flip a switch on the back of the unit to go from DVI to S-Video/Component/RF. The same holds true for the DVD/VCR combo I have (Component vs. S-Video/Composite/RF uses a switch on the rear) What a useless mess!


I am going to convert everything over to component in a few days when my cabels arrive and run anything requiring HD and 5.1 thru the receiver since it has 50Mhz response on the component feeds which is ample for HD and minimal signal loss. I will run the new Panny DVD recorder thru an S-video feed for regular tv watching and recording and move the current DVD/VCR combo upstairs. This eliminates the switchs and questions.


This way the family only has to switch between Video 1, Component 1 & RGB1 for TV, HTPC, DVD, PVR and Stereo - Far less confusing to all involved.


Michael
 

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Discussion Starter · #10 ·
Quote:
brvheart:
Sorry, I just had to chime in on this one.
I'm glad you did, especially since I got the idea from one of your posts in the first place! (Thanks, by the way. Immensely helpful.) :)


Tomorrow afternoon I'm getting digital cable + HDTV through Comcast in the East Bay. However, I'm hesitant to hook my TiVo through the digital cable already because of possible errors changing channels using the IR blaster, and your comment makes me wonder if the digital channels will look worse than having my TiVo do the tuning itself -- it sounds like the answer is yes, huh? If only I could get Sci-Fi without having to go digital....


I really hope the HD revolution comes quickly, but I can at least deal with the picture quality I have right now. If that involves using digital cable for only the HD stations, then so be it.
 

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Discussion Starter · #11 ·
Quote:
Originally posted by Datalux
You have to answer a question on the menu and physically flip a switch on the back of the unit to go from DVI to S-Video/Component/RF.
Ouch! Apparently on this 5100 box, all outputs are active simultaneously, which is nice. I think there's only one set of audio inputs, though. :(

Quote:
This way the family only has to switch between Video 1, Component 1 & RGB
It's kind of funny.... My old Panasonic 32" had four inputs to choose from: RF/TV + channel3 VCR, component for DVD, svideo for TiVo, and one composite for my PS2. Now I've got to hit one button to go from RF/TV to component 1 to component 2 to component 3 to component 4 to video 1 to video 2 to video 3 to rgb 1 to rgb 2 to the SD card reader and back to TV again. I'm so glad it skips over inputs when it's safe, 'cuz otherwise I'd have to hit that TV/Video button 12 times to make a full circle. Awfully painful if you just passed the input you were aiming for....
 

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Quote:
FWIW - I am using a Zenith SAT520 STB with the Panny 50LC13 and I run HD and SD thru the STB @ 720P via DVI and while the SD stuff doesn't look that great, it isn't too bad either.
It should be noted that the poor quality SD over component that we're discussing is on Motorola DCT 5100. I think you know this Datalux, I'm just pointing this out to others that might read this. Your results may differ from device to device. But this is a common HD STB seen accross the country, and this issue should be brought up. (which Cobalt has in it's very own thread)

Quote:
Tomorrow afternoon I'm getting digital cable + HDTV through Comcast in the East Bay. However, I'm hesitant to hook my TiVo through the digital cable already because of possible errors changing channels using the IR blaster, and your comment makes me wonder if the digital channels will look worse than having my TiVo do the tuning itself -- it sounds like the answer is yes, huh? If only I could get Sci-Fi without having to go digital....
I'm not following you completely. I haven't heard about problems with Tivo changing channels on the DCT, but then I haven't read much about it. But as far as digital channels, the Tivo wouldn't be able to tune those itself. The DCT would have to do it, then pass an output to the Tivo.


I shouldn't be too rough on the digital channels. In most every regard, they look better than analog channels. But I don't think that they should be marketed from a "quality" standpoint, when it is obvious digital carriers are used for quantity. They are quite compressed. The digital channels will often look worse than analog channels when being output via component on the 5100. This should be avoided.


cobalt, where in the East Bay do you live?
 

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It's the same with the Scientific Atalanta boxes. Analog channels will always look better when using the TV's comb filter vs. the STB. I've tried watching analog channels via component, composite, and S-video and the coax input blew them all away. I actually watch all non-HD channels via the coax input, and HD channels via component (obviously!). I even find that the digital channels appear clearer via the coax input vs. component. The PQ is much closer than the analog channels, but for some reason the coax input still wins.


Regards,


PBC
 

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Discussion Starter · #14 ·
Quote:
Originally posted by brvheart
It should be noted that the poor quality SD over component that we're discussing is on Motorola DCT 5100.
True, though my curiousity as to its source and commonality is part of the reason I brought this up. E.g. I was wondering if it was true with virtually any SD signal and whether it was usual for a TV to apply extra filtering to various sources to account for this kind of noise.

Quote:
I haven't heard about problems with Tivo changing channels on the DCT, but then I haven't read much about it. But as far as digital channels, the Tivo wouldn't be able to tune those itself. The DCT would have to do it, then pass an output to the Tivo.
Yeah, I wasn't very clear, but you pointed at the source of the problem toward the end there. Keep in mind the TiVo has program guide data and knows when and how to change channels, and in fact needs to be able to change channels in some fashion to get all its features to work. Basically, I have two options to get my TiVo to work:

1) Hook the RF coax directly into it. Get analog channels up to 82, having the TiVo tune the channels. Everything proceeds exactly as it used to.

2) Hook the svideo/composite output of the DCT into the TiVo. But since the TiVo needs to be in control, you have to hook up an infrared transmitter to the TiVo and tell it which model of cable box you have, and it will punch in the channel numbers to the DCT. This is, of course, slower because of the extra step, and slightly less reliable because IR is never very reliable; it might have interference with other IR signals, for example.


Anyway, I lose reliability if I choose option #2. It sounded for a moment that you thought the digital channels were worse than the analog ones, so letting my DCT do the tuning would make me lose on quality as well, though it sounds like that may be too strong of a statement. (Nevertheless, just for reliability alone I might want to stick with option #1 and forego the three-digit channels being TiVo-able.)

Quote:
cobalt, where in the East Bay do you live?
Dublin, a few hundred feet from the San Ramon border. You want to come install my cable tomorrow? I've got a noon-to-4 window. :)
 

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For what it's worth, I have TWC in Houston, and the SD channels are all the same to my eye whether coaxial, S-video, or component.

I tried them all, and maybe the S-video is a little bit better, but I can't really tell.


I watch everything w/ component and it is fine. I don't have to switch inputs either when going to HD.


I have Panny PT-50LC13 and love it. HDTV is awesome.
 
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