Chris Shooter

Switching Component vid through Onkyo receiver

I have just entered the HD/HT world, and boy, am I happy! I purchased the following:

Samsung TXN3075WHF 30" Widescreen HDTV
Harmon Kardon DVD22 Prog. Scan DVD player
Onkyo HTS760 6.1 HTIB

and just got setup with Brighthouse HDTV service.

I am using the receiver to do the video switching for me between the following:

HK DVD player
XBOX HD
HDTV STB

Does this receiver have any problem sending a full, clean HD signal through to the TV? The picture looks great to me, but I don't have 'trained eyes' like some of you might have, so to me it looks great... but to you it might not. I have heard pros/cons from co-workers on using the receiver to switch for me. Any education in this area would be helpful!!

Chu Gai

If you're using a receiver for video switching, then the bandwidth of the receiver should be 3x that of the signal you're putting in. If you're ouputting regular 1080 from your DVD player, it has a bandwidth of about 35 MHz so in order for there to be neglible visual degradation of the signal, the receiver ought to have a bandwidth of about 100 MHz. Regular old DVD signals are somewhere in the vicinity of 5 MHz.

Now it's up to you to determine just what your receiver can do and what signal you're putting out. Do the homework and you'll get your own answers.

Shane Martin

Chris,
Call Onkyo and find out what is the bandwidth of the component ins on the Onkyo. Personally I'd avoid the switch if you can for now. I'd be willing to bet its not 100mhz.

Chris Shooter

If I recall from the specs in the manual, it might have said it was operating at 50Mhz bandwidth. If so, would I notice a difference if I just ran it straight to the TV instead of sending it through the receiver?

Shane Martin

Probably. I would most definitely. The easiest way to tell is to use test patterns like what is on Avia.

Chu Gai

50 MHz will allow you to run 480 out of your DVD without any problems. Consider that broadcasting studios, remote locations, etc. use switching all the time. You're safe.

Chris Shooter

I also have the HD STB running through it, and I believe they are using 1080i. Am I still safe?

Chu Gai

You'll get more signal loss (1080 is ~35 MH) and you'll have to determine if you can compensate at the TV. Generally you'd be looking for a video bandwidth of 100 MHz or better. This is one of those things that you'll have to visually determine for yourself. You see, generally when a manufacturer says that the video bandwidth is say 50 MHz, that means that at 50 MHz, the signal is 3 dB down. This can also be expressed as 1/2 strength. Consequently, at 35 MHz, maybe you've lost 30% (I'm guessing) of your signal.

Chris Shooter

I will try it both ways this weekend (source direct to display vs. receiver switching) and see if I notice a difference. Thanks for the info...