HD Video Switching - Inexpensive Solution (1 Viewer)

[Jay_E]

Yup, however, read closer--the cheaper Inday model is remote controllable, but does not have discrete codes for each video input--that is, it makes you cycle through each input until you have the right one.

If you already have your own pronto Inday will sell you the model that accepts discrete codes for the lower price ($168) and not include the remote control.

Jay

 

[Andy Anderson]

Jay

That's very cool--I didn't know that. Unfortunately, I don't have a Pronto--I have the big ol' Sony learning remote. That's a cool offer, though.

 

[Aaron H]

I just was reading thru this thread
http://www.avsforum.com/avs-vb/showt...0&pagenumber=1
and on page 3, there is a guy who has made something that seems to have the best of all of these units. Has 4-in, 1 out, switches digital audio, does the automatic switching like the AA, but also has IR reception like the Inday. If this thing really ships mid-Jan, this will be the piece to beat for sure.
Here's a direct link to the new product. Oh, and I like the 1 rack space case much better, too.
http://www.zektor.com/hds4/index.htm
Aaron

 

[Bob McElfresh]

The Zektor unit looks good. I tend to avoid listing the switchers that use BNC connectors as these are production-studio products that require BNC->RCA cables, or adaptors, and cost several hundred dollars more than what we would use in our homes.

 

[Luke_Y]

Bob, I didn't read the AVS thread but the pics on the Zektor link show RCA connectors not BNC- Just FYI
Also, if you are still looking in on this thread I was still kind of curious about my earlier question

To be honest, people have run HD video through older receivers and not noticed any signal problems. The roll-off of the higher frequencies takes either trained eyes or electronic equipment to measure.

Thanks

 

[hef]

i,ve put a few other posts elsewere on this forum, but i'm still not sure about which switcher to get. i like the sound of the JVC jx-s111, but is the bandwidth to low for my large TV?(i have the hitachi 65twx20b) i don't want to buy something that won't put out the better image for my DVD and XBOX. or is the inlay or audio auth" the better way to go because of the higher bandwidth?

thanks

 

[Bob McElfresh]

Bob, thats sort of what I was thinking, and what I was figuring Denon was insinuating. What kind of things would a "trained eye" notice

Good question. I dont know.
I'm trying to figure out what part of the HD video is contained in frequencies above ... 20 Mhz. These signals will be reduced - a bit! And this is the important part: a bit.
If it was simply some colors in these higher frequencies, you could adjust for it by the controls on your TV. If you have to really tweek the controls to compensate, I suspect there will be some side-effects like a little loss of focus/bloom/over-shoot.
But even with these problems, the picture will still be many times better than an ordinary interlace TV.
It would take a trained eye to notice, and frankly the people who have discovered bandwidth problems are using video analysis equipment to tell.
PS: I have not gotten the offical word from Yamaha, but I did speak to an engineer. He recollects that when they claim a receiver has something like a 80 Mhz bandwidth this means that all the signals below this frequency drop less than 3 db. I trying to find out if all the other receiver manufacturers use the same criteria.

 

[Luke_Y]

Thanks Bob.

 

[Bill.P]

Hello, Bill from Zektor here. I just found this nice forum, and signed up so I could respond to some posts regarding the Zektor HDS4. I don't want to spam the group here or anything, but I am happy to answer any questions about the product.

Aaron wrote:
...Has 4-in, 1 out, switches digital audio, does the automatic switching like the AA, but also has IR reception like the Inday.

The HDS4 doesn't do any auto-switching. I found that to be an undesirable feature, as you don't have very good control of th switch, and are forced to turn of devices in some cases in order to switch.
There are some people that prefer the autoswitching, but with total control of the box through IR, a macro capable remote such as the Pronto can make it seamless.
-Bill

 

[Bill.P]

Luke and Bob,
Let me help with a couple of your questions.

First understand what signals are in component video.
The 'Y' signal (green connector) contains all the sync pulses, and a full resolution image.
The 'Pb' signal (blue conn.) is a half bandwidth channel.
The 'Pr' signal (red conn.) is also a half bandwidth channel.

These signals come from an RGB source, and are encoded so that Y carries Luminance + Green, Pb carries Blue - Y, and Pr carries Red - Y. Processing these three signals can derive the original red, green, and blue signals. The Pb and Pr signals are about half the resolution, but our eyes have poor resolution when it comes to colors, so we don't notice the loss. The actual encoding is more complex than I have described it, but the formulas aren't important here.

If you do the math for 1080i mode, there are over 31 million pixels per second. There are also dead times with no picture information such as sync pulses. Assuming one pixel is black, and the next pixel is white, the signal must go from the lowest value to the highest as quickly as possible. These fast rise time can contain frequencies of over 30 MHz. Fast rise times like this would only occur on images with sharp vertical edges, thin lines, text, etc., and only in the Y channel. Whenever 1080p arrives, it should double the bndwidth.

So the original question was, what would lack of bandwidth look like on the screen. Well since the Y signal would be affected most, and given your eyes capability to only see B&W in high resolution, the sharp edges would be softened. Colors should look fine unless the bandwidth gets real ugly, like perhaps less than 15MHz.

As far as bandwidth claims go, when someone says 80MHz bandwidth that means that at 80MHz the signal is 3dB down from the input signal. 3dB means 50% power, or 70.7% of the voltage. This is standard practice for science and engineering, not just consumer equipment.

-Bill

 

[Aaron H]

The HDS4 doesn't do any auto-switching

Bill,

Sorry, of course you are correct. I have been researching these component switchers for a while, and also following this thread. When I saw mention of your product over at AVS, I was really excited, and came over here to share the good news. I apparenty had some of the facts messed up. Again, I apologize, and also realize that the auto-switching isn't a good feature - really the one thing that kept me from buying the AA unit by now.

Aaron

 

[Bob McElfresh]

Hi Bill. Welcome to HTF!
We always love it when industry people participate. It really helps to get past the marketing department. (Dont get me wrong, Marketing has it's uses. But sometimes we want the more in-depth information.)
So HD Video still follows the Y/Pb/Pr encoding of component video. Good to have this confirmed.
On the 3 db issue: does this hold true for coaxial cable or only the electronics/switchers?
I thought the rule was to take 2X or 4X your highest frequency and make sure the coax could handle it with less that 3 db drop. (I used to think it was a 15 db drop).
Here is a Canare frequency response chart for their coax:

Is this your understanding as well?

 

[Bill.P]

The 3db rolloff spec is a standard measure used for coax, amplifiers, filters of all types. It works for audio (as in sound pressure), electrical, optics, radio, and anything else that needs it's bandwidth expressed.
I hadn't heard the 2x or 4x rule, but in some cases more bandwidth is not desireable. In the case of system or switch that uses amplifiers (including zero gain amps), excessive bandwidth can pickup RF noise, which will also be amplified. In some cases the energy spent to amplify the noise is energy taken away from amplifying the main signal, and something will be lost in the process.
On the other hand a cable is a transmission line. Ideally you want all of your transmission lines to be zero loss, and be perfectly shielded from the outside world. The only thing to be gained by excessive bandwidth in a cable that the frequencies of interest might be 0.1dB loss instead of a lesser cable that has 3dB of loss at the same frequency. Also as the Canare graph indicates, the longer your cable run, the more loss. My cable run from my equipment to my projector is 35 feet, so I bought cable with excess bandwidth to make up for the long run.
So when it came to deciding how the HDS4 switch was going to work, it was obvious that placing an extra amplifier in the middle of the transmission line was not going to get me anything besides amplifier noise, and some undesired gain or loss. That is why I designed it as a passive switch, and kept all signals well shielded from everything, including the other signals.
And don't get me started on marketing...
-Bill

 

[Luke_Y]

Bill, welcome to the HTF and thanks for contributing.

 

[Bob McElfresh]

Someone mentioned the Sima switcher, but I've come to discover that it's not component or HD compatible.

 

[Michael D. Bunting]

Is anyone actually using the AA switch yet? I really need one (not sure of what brand) bad!!! I just haven't pulled the trigger yet and ordered one.

Here is what I have:

Display: Sony 57HW40 (2 Component Inputs)

A/V Receiver: Denon AVR-3802 (2 Component Inputs & 1 Component Output - Digital Audio Inputs: 1 coaxial, 3 optical)

Current Component Sources:

1. DVD (Panasonic RP-91)
2. XBOX
3. HD Cable Box (Motorola 5100 from AT&T/Comcast)
4. HTPC (Nearly complete)

Future Component Sources:

1. HD Tivo (I'm so happy these were announced at CES a couple days ago - I can't wait to own one!)

The Denon AVR-3802 receiver is really somewhat short on digital audio inputs...as it only has 3 optical and 1 coaxial (they are all assignable, which is cool though).

But I find myself needing more and more each day it seems!!!

I use the lone coaxial input on the 3802 for my Laser Disc player (Pioneer DVL-909) and combine that with an S-Video cable from the LD player directly running to an S-video input on my TV , and this really throws things off for me as far as digtal audio inputs are concerned.

This leaves me with 3 optical inputs for my 4 digital sources - all using optical cables (DVD, XBOX, HD Cable Box, and HTPC).

Any feedback on the AA model...or even the JVC model is much appreciated! TIA!

 

[Aaron H]

HD Tivo, huh? I hadn't heard about that. Do you have any news or pricing info you can share?

Aaron

 

[Michael D. Bunting]

It (HDTV SUPPORT) was just announced at CES the other day - pricing/exact specs have not been released yet to my knowledge.
Here is what I know:
Tivo will offer standalone HDTV PVR's and a DIRECTV HDTV PVR.
Both will be capable of recording ATSC OTA signals and satellite broadcast signals.
Click on the link below for tons more info and press releases...and while you are there, dont forget to check out the new TiVo HOME MEDIA OPTION!
TiVo at CES
There is tons of discussions on it over on the tivocommunity forums as well:
TiVo Community Forums

 

[Jason Cald****]

I just rewired and hooked up my system the other day.
I bought a used Audio Authority 1154 off Ebay since there is a 2 week wait to send out new ones.
I have 6 things now that use component outputs and only 2 inputs on my Sony 57hw40.
Slot
1.Xbox
2.PS2
3.DVD
4.Replay 5080
Direct connected is my Motorola HD cable box to the TV.
I still have my Gamecube that is not hooked up but i just swap it with slot one. Works for now until i upgrade to seperates.
I love this though, my Denon AVR 3200 has 2 digital inputs one being coax and of Tos. Its nice you can hook up either coax or tos connects and use either out to the receiver.
With the auto switcher if you have your cable box or DVR hooked up just put it in the last slot and it works great.

I would highly recommend this to anyone.

 

[Michael D. Bunting]

Jason

Thanks for your feedback on the AA switcher. I think I'll look on ebay as well - or maybe just order one new...

BTW: We almost have the same setup:

-Sony 57HW40
-XBOX
-Motorola 5100 (Looks like you have the silver one - mine is black)
-Denon 3802

And I used to have a Replay 5080 myself - brfore going with a Series 2 TiVo. But that's another discussion for another time...

thanks again for your help!