2x6 matrix HD+IR+M.ch Audio distrib. over Cat6


Established Member
Heres the plan:

Large Victorian house being gutted and renovated.

I have most of the displays already. 4x 720p PLasmas
Will be adding 1x 1080p Philips 21:9
1x 1080p PJ

Will be adding 7.1 HDMI audio capable receivers for each display. Some will be cheap small bluray/receiver sub sat systems. The 1080p displays will get more substantial audio equipment.

Each display will get an XBMC media streamer box pulling content from a server so thats 1 CAT6 to each display from the getgo.

However I also want to share 2x SKyHD boxes to the 6 displays.

SO I know I am into matrix switching. Distances involved mean I know I am into HDMI over CAT6

First I want to ask about EDID handshaking where Lowest common denominator signals take over.

Am I correct in that having a multi channel audio reciever for each displays means no worry about the default lowest common denominator reverting to Stereo PCM2.0

However in terms of video, even if the native res 720p displays are capable of scaling a 1080p signal, will they still force video even on the 1080p displays down to 720p?

Do HDMI over CAT6 baluns carry HDMI audio too.

D0 the matrix switchers like the OCTAVA HDMI/CAT6 matrix support HDMI multichannel audio over their CAT6 outputs. If not and they only suport toslink, does that still run over the same 2 cat6 runs for each output?

Multi channel audio for each room from the 2 Sky HD boxes is not a deal breaker for me. Nice to have alright but seeing as each room will have a Bluray player for event movies or shows/docs that would be purchased on discs, I can live the PCM2.0 and PrologicII for Sky material

So am I talking 3 CAT6 runs to each display. 1 for my internet access and media stramers in each room connectted to a gigabit network switch and 2 runs for the HDMI matrix switching?

In terms of how matrix switchers work specifically the OCTAVA.

I take it any number of the displays can view either HD box at the same time. 2 people in the house get first choice/refusal on control of a given HD box. ie. They alone have the right to take control of a box and lock it to themselves wherever they are. If a non preferential user is on already on both boxes, they have no choice but to 'suck it up' if a preferential user changes channel. So can the control of the source be locked to one of the displays/rooms/people if you know what I mean. What I mean is, say no one is watching anything on either of the boxes and myself being one of the 'big 2' :D pick a room. I pick one of the HD boxes as my source for that room. Can I lock control of that box to my room for the duration of my stay. If someone else wants to watch something on HD, assuming the other box is still free, they can watch whatever they like via the second box. However if a third person comes on, they have no choice but to watch whatever someone else is watching on HD box 1 or HD box 2. If the third person is a 'Big 2' person they can take control of the second box however.

Oh dear, I am tying myself in knots here trying to explain what I mean. Hopefully someone can dicipher what I mean and answer :D
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Distinguished Member
If you intend to have IR control to the sky boxes in each of your six locations, then anybody can control from any location at any time, so remote wars can ensue!! I don't think you can lock people out, unless you mean not all displays will be capable of IR control. Probably easiest just to have limited number of remotes (say 2 or 3), that way you can only change channel if you have a remote in the room.

SkyHD only does stereo over HDMI, if you wanted 5.1 you would need to distribute the optical (or digital coax) output along with the HDMI signal. You maybe able to combine these signals but I'm not sure.

Member 319784

Prominent Member
What you are looking to do is mightily challenging for the vast majority of HDMI distribution hardware on the market currently.

Mixing different displays with different resolution capabilities causes big headaches.

The 1080p signal will almost certainly be downgraded to a 720p signal. That, or you choose firmware that forces the 1080p signal, which will ultimately result in your x4 720p displays not displaying an image at all.

We have a new HDMI distribution system called HDMI over IP - this system enables you do distribute 1080p, IR and 5.1 audio over a single Cat6 cable.

The beauty of the system for your particular purposes is the in-built automatic resolution adjustment. This function downscales the 1080p image to match the native resolution of the attached display as reported in the EDID. Because the HDMI over IP Receivers have in-built resolution adjustment, you can go ahead and set your HDMI sources to their highest resolution supported. Enjoy the 1080p content on your main screens, and watch 720p on the other screens.

For the HDMI over IP solution you will only require a single Cat6 cable, not 3.

You can get use a DVI to HDMI converter to add the 5.1 audio stream onto the HDMI output from Sky HD. This will then enable you to listen in full 5.1 surround at any of the receiver locations.

You mention you already have a gigabit ethernet switch. Do you know if this is a managed switch? If so, we have a number of options for how you control the system in your home for the easiest Matrix switching around.

Joe Fernand

Outstanding Member
AVForums Sponsor
Hello Calibos

As long as all of your Displays support 1080p 60/50 (no mater the native resolution of the Display) there is no need for the Matrix to force the source to 'down convert'.

1080p24 is slightly trickier as many 'older' displays don't support 24p.

Where you do have a mix of displays and some that don't support 1080p signals its usual that all displays will support 1080i 60/50 and that's what the Source will revert to - not 720p.

The Octava Matrix will support multi channel audio if your 'Sync' device also supports it - your AV Amps being the Sync in the audio chain.

The Octava Matrix is a full 'non blocking' Matrix - you can set up any combination of Source and Display as you want.

Controlling the AV system is not the function of the Matrix - the Octava Matrix has a simple IR Passthru facility that will be sufficient for some but not all installations.

There are lots of options in terms of system control - the level of complexity/control required will determine what you should be considering and the type of budget involved.

From what you describe the Control system is going to require far more planning/budget that the AV signal management.

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Established Member
Wow, thanks guys for the comprehensive advice on my options.


Unfortunately I don't have a switch yet but even when I do install one did I not read over on AVS that one needs an enterprise level managed switch that won't melt under the heavy switching workload of these HDMI over IP devices. Not only would I be running these HDMI/IP devices over the network, I'd be running Terabytes of archived music and video via XBMC over the network to each room too. Quite often both at the same time. 6 people in the house you see. Chances are some will be watching SKyHD and others watching content on the server at the same time. If I am just streaming content from the servers over the network I can get away with a cheaper consumer grade switch.

I also read that there is some compression going on inside the senders to get that 6gbps down the single CAT6 pipe. PQ degradation from the compression maybe not noticable to a lot of people but there is some degradation there, is there not? Now it still might the option to go for but I guess it kind of depends on whether the price for the 4x8 Octava is the original GBP2901 or discounter GPB1419 listed on the site. If the former, the price of all the HDMI/IP senders/recievers might be competative. If the latter, then I am prepared to make some compromises to functionality to hit that pricepoint.


Can we talk about multichannel audio. You talked about the syncing device which is the amp. I understand that. The amp needs to be able to decode multichannel audio coming in on their HDMI inputs. Are you saying that the Octava matrix switches pass HDMI multichannel audio over the HDMI outputs only, or can they pass it over the CAT6 runs too?

This is the model I am looking at. Octava HDMX48CAT-UK 4x8 HDMI CAT6 Matrix Switch + 8 x CAT5 Receivers . Don't know where I got the 4x6 from. Its a 4x8, which I suppose is better in the long run. I'll wire up every single room even those I don't envisage ever having a Display in, if I have 8 outputs to play with.

Also whats this spec about: Optical Audio Ouput for integration with surround sound system? Can't see any optical outs on the image of the device on the website?

Regardless of whether it can passthru M.ch audio, that is not a dealbreaker for me. Nice to have but not absolutely essential. After all, each location will have a local Bluray player anyway. (Probably an ASrock330 Nvidia Ion box with Bluray drive running XBMC. ie. Primarily used as a streamer but with local bluray playback to be used on occasion) And as DwWhite said, Sky doesn't do M.Ch audio over HDMI anyway. (Though I did read this might be enadled in a future firmware update)

Now in terms of 'Planning the Control system' Again, the kind of control I was talking about with preferential users being able to lock a source to their display etc. That was a nice to have, not a must have. We can manage with the old analogue oral/aural method of shouting up the stairs, "Oi ! I'm watch something on SkyHD now!" :D

I am wondering how the source display switching works in practice. I know that the switch just passes through IR signals to control the sources, but how does one select which source one wants to watch from the display/room end. Do the recieving baluns have their own IR codes for source switching while passing through all the source IR codes?

To recap in terms of control, I am more interested in getting the basic functionality at the cheapest price, ie 4x8 matrix switching via Cat6 of video and 2ch audio. Anything else is a bonus but not a dealbreaker

Member 319784

Prominent Member
It is a misconception that the ethernet switch will melt under the workload of the HDMI over IP devices. The system does not use as much network traffic as you might think. On average the switches that we have tested with the system run at around 4% capacity with devices broadcasting anywhere from 30-60 megabit streams. Because the HDMI over IP system uses multicasting you can have as many receiving units as you want with out adding any additional load to the switch.

You could of course have a dedicated ethernet switch purely for the HDMI over IP distribution system if you wanted completely uncontested bandwidth.

In terms of picture quality. When comparing a side-by-side comparison using two identical screens, one connected directly using a HDMI cable to a 1080p source, and a second screen connected through the network using HDMI over IP, you will detect a minor difference. The larger the screen size, the more visible that this difference will be, however, for the vast majority of people using screens under 50” and viewing from the recommended distance, the difference in picture quality will be negligible. We use a live JPEG2000 CODEC optimised for motion. Text and large areas of the same color (i.e. a solid black screen will show some artifacts) present the biggest challenge for the device. However, people who witnessed this solution being demonstrated at CEDIA said the image quality would be more than sufficient for most of their customers. HDMI over IP is not a "perfect" solution, but a close to perfect solution that gives an alternative option for distributed video.

In addition to this, several CEDIA award-winning and award-nominated installation firms are already beginning to implement HDMI over IP solutions for some of their clients. They were very impressed with the picture quality and the HDMI over IP technology in general once they had seen a demo, after being sceptical at first.
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Distinguished Member
In addition to this, several CEDIA award-winning and award-nominated installation firms are already beginning to implement HDMI over IP solutions for some of their clients. They were very impressed with the picture quality and the HDMI over IP technology in general once they had seen a demo, after being sceptical at first.

Hope its better than the Cisco system which is pretty awful with real life video


Established Member
JUst wondering if Joe can chime in here.

In one room I need to be able to re-arrange the room and re-position the TV to another wall every Christmas time.

ie. The runs coming to that room from the server closet which terminates at a wall plate on the wall where the TV will be located most of the year. Can I splice in a Branch run from that wall plate that feeds another wall plate at the Christmas TV location. Will that intefere with the OCTAVA and recieving baluns. Or should I just budget for running two distinct runs from the server closet to that room, each going to a different wall plate at the two room locations. So at Christmas, I move the TV and swap the cables at the OCTAVA to those that feed the Christmas time wall plate in that room.

Member 213491

Established Member
Hello calibos,
Joe's away for the week, As for the cabling i would have two distinct runs, Just swap the Baluns on different paths.
As for current solutions of HDMI over IP the Switch wont melt down but the down side is the picture quality. I will post some pictures to show the results.


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