Decent Analog>HDMI

[jackstraw]

I'm adding a projector, and I'd like to run just 1 HDMI cable. Main input sources are simple (HD A2 and Verizon FIOS -- both via HDMI), but I'd also like to be able to use component (for Gamecube and maybe a WII). I see several receivers with component>HDMI conversion, but on units like the Onkyo 605 I've read about the conversion adding black bars.

Are there receivers that do this well in the <$700 range?
Or, am I going to have to run more cables to get this to work well?

[santora]

I've not heard of the problems with the Onkyo 605/805 other than the sometimes audible clicking problem which seems to go away when the unit is broken in. But if you're really worried, the 875 has gotten stellar reviews and uses a different chipset for upresing than the 605/805

[jackstraw]

The black bar issue that I mentioned was noted on post #14 of the 605 thread. I'm serious about <$700, so while I'm sure that the 875/905 are great, they aren't realistic unless there are crazy deals I just haven't found.

See http://www.hometheatershack.com/foru...html#post41877

[gsmollin]

For that price range, frankly, run the component cables. A video processor is required to get decent component>HDMI conversion, and those are expensive. For less than $3k, AVR receivers don't do a good job with conversions.

The Wii and Gamecube are not critical applications, and I suppose you would be satisfied with an inexpensive conversion, but component is capable of beautiful performance. Running the extra cable is really worth it.

[jackstraw]

Thanks for the advice. I'll consider adding a component cable after I see how the HDMI response is. I guess I could consider running something simpler (SVideo or Composite) and letting the projector do all of the upconversion/deinterlacing.

Projector is a Panasonic AX100U -- I've read that deinterlacing is fairly good on this unit.

[gsmollin]

Akk, gasp, no, don't run s-video or composite video as a substitute for component video! They are NOT capable of a beautiful picture! I would stack up component video against HDMI any day, and with a cable run > 10 meters, component would usually look better. However, the HDMI connection is the only connection you can use for up-converting DVD to 720p, so you do need that connection. However, component video can be used for cable, OTA tuner, HD DVD, Wii, Gamecube, and many other sources. The switching for component is also cheap and simple, and works very well in an inexpensive AVR.

[Sonnie]

Ditto... whatever you do... DON'T use s-video or composite. You'll have us all crying...

[jackstraw]

Right, for HD sources you need something better. I figured that for my Toshiba HD A2 and main TV source (soon to be Verizon FIOS) I'd use the HDMI. I can consider running component for them as well but I'm hoping that the HDMI will work well (in-wall run is 35' Monoprice tin-plated copper 24 AWG).

All that I was suggesting using the cheap approach for was non HD video games.

Is there a highly recommended component cable that is reasonably manageable for in-wall installation?

[gsmollin]

For in-wall installation I recommend RG-6. It is cheap, low-loss, and the F connector never falls out behind the wall. Use a F-RCA adapter that is through-mounted ona wall plate. They cost a few bucks.

[brucek]

I would stack up component video against HDMI any day,

So component provides a better picture? Is cable length a factor when comparing the two?

brucek

[gsmollin]

brucek wrote:

So component provides a better picture? Is cable length a factor when comparing the two?

brucek

Component video provides a picture essentially equivalent to HDMI. It is slightly softer, but that can be a good thing on a 720p projector which may be prone to SDE. Your Panny has the "soft screen" feature which optically fuzzies-up the SDE, so you wouldn't see any difference between component and HDMI.

Cable length is a really big issue, however. Professional installer routinely run component video >100 feet using RG-6. HDMI becomes chancy beyond 30 feet, and very chancy beyond 60 feet. The problem is that the slight clock skews between the three channels build up on the longer cable runs, and HDMI will abruptly show "sparkles", which signals the breakdown of the digital differential timimg. Component just gets softer as longer runs lower bandwidth. I don't know what the max length for component is, but it is a long way.

In my own installation, I had a 35 foot 28 gauge DVI cable between my Oppo 971 and Infocus SP5000 pj. It worked. When I replaced the Oppo with a Toshiba HD-A2, I got sparkles. I had to replace that cable with a 24 gauge version. The 24 gauge HDMI cable wants to fall out of the back of the equipment rack because all of the twisted pairs are as thick as your thumb, and the cable is too stiff. Going into the wall to the PJ, I am still using DVI connectors because they can be screwed down. I would not use HDMI if it weren't forced on us by the content providers. No current DVD player upscales over component, and some day no high definition player will provide HD over component either. So we are stuck with HDMI, but I don't care for it, and I use component whenever I can.

[jackstraw]

Thanks for the input, guys. I am using an HD A2 and Comcast DVR current (Comcast will be swapped out for Verizon FIOS DVR this coming weekend).

My cable run is source > 6 ft 24AWG > Wall Jack > 35 ft AWG > AX100U. No sparkles yet, I'm eager to make sure that the Verizon DVR will give the same result. I'm planning to add another wall plate and a 3 ft cable at the projector, I hope this isn't pushing it over the limit. I feel your pain on the stiffness of the HDMI cables.

If I end up adding anything, it will be component. I don't see a need for it yet. I understand the analog>HDMI upconversion won't be ideal, but HDMI switching on the receiver should be fine, right? Of course, there's another length of cable to potentially push me over the HDMI limit...

[gsmollin]

The HDMI switch in the receiver has a repeater, so the cable length before that is not added directly to the total, because the repeater has gain and regenerates the fast rise & fall times of the original signal. However, repeaters don't have time base correction, so the timing problems do add up, and any timing problem in the repeater adds in too.

Still, the 24 gauge wire should work at 720p.

[lcaillo]

What kind of timing problems tend to cause problems in repeater systems?

[gsmollin]

HDMI uses differential signaling, which is a balanced system that depends on the differences between the channel signals to detect the digital video signal. The problem is that there are at least three channels running concurrently to make up a HDMI signal, similar to component video, VGA video fora computer. The problem is that even small timing differences between the three channels will cause the entire signal to fail, and you get sparkles in the picture. A repeater does not correct these timing problems. It only regenerates the signal in each channel. So timing mis-matches accumulate between the three channels as the cable gets longer until the signal fails to recreate the original video.

[lcaillo]

Do you have some reference for this correlation between inter-channel timing error and sparkles? And is this timing error meaningful in real world applications? Is this the common failure point in this kind of system?

[gsmollin]

Here's a link you may find informative. There are many others. The clock-skew problems with HDMI have been widely discussed.

http://www.extron.com/company/articl...?id=dvihdmi_ts

I'm guessing your second question is similar to those questions about expensive speaker cables, where you can spend $1000 on a speaker cable, and it sounds the same as $10 cable. This is different. The signal is extremely wide bandwidth, and once sparkles appear, the picture is ruined. You WILL SEE the sparkles, if they happen. This is not a nuance, it's a disaster.

There are so many ways for an HDMI system to fail. They boil down to two types. Those caused by hardware, and those by software. I have had problems with both. Hardware we have already discussed. Software problems are worse, since you can't fix them. The show up as dropped handshakes that make the picture flicker.