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In an article in The Perfect Vision (NovDec 2000), Gary Mershon tested 23 receivers to see if their component switching was degrading the signal. The key, as you mentioned, is the bandwidth. Apparently, according to his article, a progressive DVD signal (480p) requires less bandwidth than a high definition signal requires. He found that 13 MHz was sufficient for this signal.


However, he found that high definition (HDTV) required at least 33-37 MHz. As a result, only 3 of the receivers he tested passed! You'll find a little variation sometimes with what the ads say versus the specs. For example, I've seen the Denon 5800 listed as either having 30 or 50 MHz in bandwidth on its component switch. The Integra DTR 9.1 and RDC-7 offer 45 MHz. Yesterday, to my astonishment, a Krell engineer claimed that its HTS2 pre/pro could switch a component signal at 10MHz. I don't think so. Clearly, he was thinking of a DVD signal. So be careful and quite specific about what you need.


Switches are available (I've been doing a lot of research on this in the last day) from Extron, Inline or Altinex that offer much, much greater bandwidth. An Altinex model offers 350MHz, as does an Inline.


Hope this helps some.

Leslie
 

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But I think in the real world those findings are still up for debate. I have a Denon 3801 which apparently doesnt "pass" but yet I can switch cables all day long between the component switching on it with 2 HD sources as opposed to running either STB directly to the set and I see no signal loss on either of the 2 HD demo loops. Now of course I'm using a lowly 55" Mitsu HD with 7" guns so it could be that if I had a 15K FP with 9" guns I would notice the difference.


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Dan
 

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I noiced that my Denon 3802's component pass through is rated for 5Hz - 27MHz, and that the 4802 and 5800 go up to 50MHz. Someone told me that you need at least 30 MHz for no signal loss. Anyone have any details? I don't need to use my receiver's switching now, but I'm wondering if I would ever be able to use it.


Also, would 27MHz be enough to pass a DVD signal (progressive or interlaced) without any loss?
 

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Rule of thubm is at least twice the highest frequency of interest. Therfore 60mhz is the minimum for HDTV. Analog electronics rolls off and you need the double bandwidth to keep the response flat where you are working.


That said with the less than ideal quality of today's consumer HDTV's, 27mhz is acceptable.
 

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I have the 3801 and have it switch between my HDTV tuner and my Panny RP-91. Although I haven't compared the results with a direct connection between the STB and my Sony HS10 (maybe afraid to find out if there's a significant difference http://www.avsforum.com/ubb/wink.gif ), I find the HD picture to be quite acceptable (even phenomenal with true HD material, such as the PBS loop or with some of their recent HD broadcasts such as the recent Italy flyovers mentioned elsewhere at the forum). Even if there was some appreciable improvement in the picture with a direct connection, the convenience of the switching more than compensates for me, IMHO.

Jim
 
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