I have a home built DVR PC running Windows 7, 64 bit with a Gigabyte GV-N450OC-1G (Nvidia GTS 450) video card in it. The card has two DVI outputs and one HDMI. I'm trying to run HDMI to every room for a bunch of HDTV's. First, oddly, if I connect a TV directly to the HDMI output it works, but if I connect the HDMI output to an 8 port active splitter/repeater ( I don't like the term splitter as that usually implies signal loss so I use the term repeater), the card thinks nothing is connected. I was able to work around that by using a DVI output with a passive DVI to HDMI adapter, and surprisingly they do provide audio on the DVI ports so everything works for up to 8 TV's with audio on the HDMI.
Now to drive more than 8 TV's, I cascaded a 2nd 8 port active HDMI repeater off of the first one. Video works, but audio does not. As soon as I plug the 2nd repeater into the first, I hear ba-bonk and the audio driver goes offline. The Windows sound settings shows "Not plugged in" for the NVidia audio ports. Unplug the 2nd repeater, ba-bonk, and audio starts working again. Rebooting does not help. Oddly the exact same thing happens with two different Nvidia cards with two different drivers. I'm starting to wonder if it is intentional, perhaps an HDCP issue? If so I'm very angry as I am doing nothing illegal!
Now here is one more piece of the puzzle and a workaround but I don't like it. For my long HDMI runs, I'm using active HDMI to dual CAT-5E converter boxes (which work great by the way). If I run the video card into the first 8 port repeater, then take an output from the first repeater and convert to dual CAT-5E, convert back from dual CAT-5E to HDMI, then run that into the 2nd 8 port repeater, then everything works and I get audio and video on every TV. But that is clunky and will require that I buy either another HDMI to CAT5-E converter, or run longer HDMI cables due to having to place the 2nd splitter on the other end of the house. Since the HDMI to CAT-5E boxes are fully HDCP compliant, this should not be an HDCP issue as the first repeater should see the 2nd repeater (media converters should be transparent) just like if it was plugged in directly.
Repeating HDMI should be a simple thing, if not for all this HDCP crap that requires bidirectional encrypted communication with exchange of encryption keys, sigh.
Has anyone else experienced this or know why I can't directly cascade HDMI repeaters?
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HDMI is a high bandwidth digital signal. It is not recommended to cascade HDMI Splitters/Extenders. I would recommend checking KVMSwitchTech as they offer a wide range of hi-end HDMI Splitter and HDMI Matrix solutions.
The fact that it's digital should make it easier to cascade than analog, where with analog you might overdrive the signal. I work in the computer networking field, and I see this no different than cascading gigabit network switches which work just fine.