# maximum cable length with triplehead2go?



## ZachRosing (Jan 23, 2019)

Hello,

I'm planning an installation with a TripleHead2Go DP edition with two DP to HDMI adapters + 100' length HDMI cables going to projectors. Are there going to be any issues with cables this long? I can't find any answers on Matrox's website. The HDMI cables have a booster built in. Trying to get some clarification before I buy everything.


Thank you!

Zach


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## ChrisB_SanDiego (Jan 23, 2019)

I've done that setup with 50' hdmi to a booster to 25' hdmi with no problem for a temp show, but I wouldn't recommend that for an installation. Not sure how a straight 100' would do. For long runs I highly recommend getting a couple hdmi to sdi converters and using sdi for your run (which is what we have for our installation, we use Blagmagic Designs HDMI to SDI converters). Or go hdmi to cat6 for your run.


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## rwhealey (Jan 23, 2019)

I wouldn't count on an HDMI cable that long. Matrox won't have any information because they don't care about what cable you are using - their device meets the HDMI spec, and it's up to you to use a cable that also meets the HDMI spec. Normal HDMI cables shouldn't be run more than 15' (depends on the cable but it's a good rule of thumb). It sounds like you have an active cable. What is the manufacturer and model of the cable you are using? There are some certified "active" cables of that length that may be usable, but by the time you have a good cable and any required accessories you could have bought an HDBaseT TX/RX pair (if you can buy used, Extron DTP transmitters and receivers are available for not much money on eBay) and run a much smaller and easier-to-handle Cat5e


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## Amiers (Jan 23, 2019)

I would agree. Nix the HDMI cable and get SDI 4g cables and sdi-hdmi boxes. You can do backmagic or Missing Link.


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## danTt (Jan 23, 2019)

Amiers said:


> I would agree. Nix the HDMI cable and get SDI 4g cables and sdi-hdmi boxes. You can do backmagic or Missing Link.


SDI conversion is going to get expensive pretty fast.


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## Amiers (Jan 23, 2019)

https://www.bhphotovideo.com/c/prod...DmSPsx9mrn-_R4aAgVsEALw_wcB&lsft=BI:514&smp=Y

45$

https://www.bhphotovideo.com/c/prod...eqAbgU3b5BlprkaAm78EALw_wcB&lsft=BI:514&smp=Y

54$


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## Butch! (Jan 23, 2019)

I definitely wouldn't run HDMI over 25'. As an alternative to SDI you might want to consider devices which 'convert' HDMI to a signal which is sent using Cat 6e cable and then decode it at the other end. This format uses Cat 6e cable, but is not an ethernet type signal and can't go through routers or switches. Get a name brand as the knock offs are sketchy on reliability. We've used gear from Altona, the 4K/UHD line and have had fantastic results in the 200' range. Their system also does 'Power over Ethernet' so you only need a power supply on one end and it sends the power over the Cat 6e cable to the other end to power the other device.


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## ruinexplorer (Jan 23, 2019)

Do you already have your HDMI cables? Length of cable is also bandwidth dependent. For 1080p60 signal, you are pushing 4.46 Gbps. Check the specs of your cable as to whether or not it can handle that. If it can't, then you will want your TH2G to be set to use less bandwidth (say 720p or 1080i).


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## rwhealey (Jan 24, 2019)

SDI is used a lot in production and broadcast but is not used as often in installations of presentation video systems - it doesn't carry audio and the cable is expensive and difficult to terminate. The HDBaseT standard is much more common, as it carries video, audio, control, power for one end, and ethernet in some implementations - all over a cheaper CAT cable.


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## RonaldBeal (Jan 24, 2019)

rwhealey said:


> SDI is used a lot in production and broadcast but is not used as often in installations of presentation video systems - it doesn't carry audio and the cable is expensive and difficult to terminate. The HDBaseT standard is much more common, as it carries video, audio, control, power for one end, and ethernet in some implementations - all over a cheaper CAT cable.


WRONG
SDI does indeed carry audio... in fact the Blackmagic micro converters linked above do convert the audio between hdmi/sdi. 
Additionally, I have found SDI extremely easy to terminate.... not sure what you are doing wrong.


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## Amiers (Jan 24, 2019)

While all that from Cat5 is nice. The source is 100’ feet from the projector. If he needs to run audio from it, it sounds like he can just swing a cable to his Audio console and call it a day. 

Still think SDI is the way to go for this one. 

You want to get expensive then go fiber to Aja’s converters.


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## ruinexplorer (Jan 24, 2019)

I advocate for fiber if you can afford it as you don't have to worry about electromagnetic interference. You can get all in one fiber cables.


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## Ancient Engineer (Jan 25, 2019)

Use HD-SDI.

Solve your video problems with video solutions, not network solutions.


We have a fleet of HDMI to Cat5e-6 converters where I work and they are _not_ awesome.
We are slowly converting them to AJA HDMI-HDSDI converters and good coax.


I don't understand the grump about terminating SDI... you can't put a BNC on a piece of coax??? (Leave your tweaker and soldering iron by the door on your way out...)


RJ-45 connectors are not fantastic for high frequency connections. Their insertion loss approaches 34dB @340MHz and around 7dB @ 100Mhz _per connector_.(ref. a)
I assume, but I do not know, that your engineering team specified a quality cable like Belden 7997A for this situation and that its insertion loss at 100M is 22dB (ref. b) A little division gives us a loss of 7.33dB for the cable in the OP example.
Most of these Cat5e type converters claim a bandwidth of around 340MHz (on a cable that will tolerate ~100MHz)...
So, in just the cabling with the connectors added in, the insertion losses are over 21dB that the receiver/converter has to "make-up".

Addendum: The reason this loss is a problem for non-network types of signals is error correction. Most network protocols monitor packet streams and report lost/bumped packets and request a re-send. I can assure you that nearly all of the inexpensive converters have limited or NO error checking capability. So when your signal goes wonky... pffft, thats all folks. 

Remember kids... every 3dB is half of the original signal... Ugh.

Looking at the HD-SDI approach we get the following:
Using HD-SDI meeting SMPTE 292 (ref. c) and a moderate quality cable like Belden 1695A (ref. d) gets us assured working distances of 100M (20dB loss at ½ clock frequency of SMPTE 292 see ref. h),
And really high quality cable like Belden 4731R (ref. e) gets us to a working distance of 182M (598’) meeting the same standard! (ref. h)
The BNC connectors used in this system are not a special variety and have an insertion loss of less than 0.2dB per connector so their presence on the signal is barely felt. (ref. f typ.)

So, yeah, skip HDMI longer than 50' (without special conditions).
Skip HDMI on NIC.
Solve your problems with good engineering practices. It will last longer and be more reliable.


Quick addendum: EN50173-1, appendix A specifies an insertion loss of 0.4dB per RJ-45 connector... at (drumroll) 8MHz. Logarithms at work...



References:
a. http://www.ieee802.org/3/10GBT/public/mar03/cohen_1_0303.pdf
b. https://catalog.belden.com/techdata/EN/7997A_techdata.pdf
c. https://en.wikipedia.org/wiki/SMPTE_292M
d. https://catalog.belden.com/techdata/EN/1695A_techdata.pdf
e. https://catalog.belden.com/techdata/EN/4731R_techdata.pdf
f. https://www.amphenolrf.com/connectors/bnc.html
h. https://info.belden.com/hubfs/resou...tal-video-distance-chart-product-bulletin.pdf


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## rwhealey (Jan 25, 2019)

Looks like I'm getting beat on the SDI recommendation, and I stand corrected on the audio capabilities.

I didn't mean to imply that _I_ find it particularly hard to terminate - just that any electrician and most IT people have the tools and can terminate an RJ-45 but would have no experience with video connectors.

I still suspect that between Extron DTP/XTP, Crestron DM, and AMX DXlink and other various implementations of HDBaseT is more widely used - there are tens of thousands of classrooms out there that use basic HDBaseT presentation switchers. At least in my world (fixed install, not production) I see far more HDBaseT, for good or ill.


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## Amiers (Jan 25, 2019)

For a permanent install the chances that a BNC connector never touched will last the length of the install and even if the cable fails time will pay for a new cable with connectors on it. 

He could even be redundant and run a spare for each projector. 

Also while HD base solution has all the extras, they seem like they just need a video solution to the projectors. The only extra that would be nice to have would be for networking the projectors. But he didn’t say he had stacks on either side.


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## ruinexplorer (Jan 25, 2019)

If you only ever need broadcast standard resolutions, SDI is definitely a good way to go. As a blanket statement, I feel that it is bad advice. SDI does not transmit HDCP. So if someone needs to use a Blu-ray player, HDMI-SDI converters will generally not work (unless they are non-compliant and strip the HDCP). In addition, if the user needs to use one of the many VESA resolution standards that do not comply with one of the broadcast standards, you will be unable to transmit video.


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## Chris15 (Jan 25, 2019)

And also reminding people that HDCP content can come form places other than BluRay, iTunes for example...
IF and only IF, you control the source 100% of the time, SDI will serve you well.
If you need to cater for someone walking in with their own laptop, then HDBT and the like, along with something in the chain that can at least EDID manage and preferably scale will be the difference between content showing and black screen...


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## MNicolai (Jan 25, 2019)

Ancient Engineer said:


> Use HD-SDI.



OP doesn't say that it's necessary for this application but HD-SDI isn't HDCP compliant. There are limitations to SDI and being able to show protected content is one of them.


Ancient Engineer said:


> I assume, but I do not know, that your engineering team specified a quality cable like Belden 7997A for this situation



Nobody has been specifying CAT5e in the last 5 years. If you're doing video, it should be on CAT6A, probably shielded. Some extenders can get by on less in exchange for being limited to shorter distances but CAT5e is all but retired.


Ancient Engineer said:


> Addendum: The reason this loss is a problem for non-network types of signals is error correction. Most network protocols monitor packet streams and report lost/bumped packets and request a re-send. I can assure you that nearly all of the inexpensive converters have limited or NO error checking capability. So when your signal goes wonky... pffft, thats all folks.



If you're talking about Monoprice-type converters, yes, but in event production I can't say I know anyone using those types of converters for the reasons you've described. In general video over CATx is HDBaseT, SDVoE, or video over IP. AVB is picking up a little steam for video over IP but so far that's primarily in conference systems. In any of those cases, digital is digital and either the signal makes it successfully to the end of the cable or it doesn't.

Of those, video over IP is the only one that's particularly risky because there is a major difference in quality at $300 encoders than at $1500 encoders due to compression. The high-end encoders are visually indiscernible from using an HDMI cable and can pass 4K60 over a 1Gb link across a network switch.


Ancient Engineer said:


> Solve your problems with good engineering practices. It will last longer and be more reliable.



In some cases, maybe. If you're also trying to control the projectors, network the projectors, want to standardize on a ubiquitous type of cable, and don't want to worry about HDCP issues then CATx extenders or encoders will be more useful to the average theater than SDI. If you're primarily doing IMAG and camera feeds, then that's a very different application and SDI is better for that because the cost of routers/switchers and video mixers with a bunch of inputs is much lower for HD-SDI.

CATx cables are not all the doom and gloom that you suggest so long as you stick with quality hardware and quality cables.


ZachRosing said:


> I'm planning an installation with a TripleHead2Go DP edition with two DP to HDMI adapters + 100' length HDMI cables going to projectors. The HDMI cables have a booster built in. Trying to get some clarification before I buy everything.



I wouldn't use HDMI over this distance with boosters. Boosters are pretty unreliable. You may be able to get something work at a lower res but turn it up to 1080p or 4k and your signal could drop out. There are hybrid HDMI cables that have fiber and copper in the same cable. These can be useful for going long distances and will work just as fine at 100' as at 230', but the cables are directional so you have to be careful when you install them. These cables are also not very rugged so you have to be mindful that you aren't going to roach the cable when you put it in by pulling it hard, twisting it, or stepping on it. The cost of these cables is generally in line with the cost of lower/mid-grade HDBaseT extenders, so I tend to go with extenders instead to avoid the hassles of accidentally killing a fiber hybrid cable. There's a wide range of HDBaseT extenders out there, but generally better quality CAT6 or CAT6A cables will carry the signal further without problems. Check the requirements on any extenders before you buy anything.

My projects tend to be higher grade installations with integrated controls so I use a lot of Crestron extenders and NVX video over IP encoder/decoders, but something a little more friendly would be anything from Atlona. More projectors above 5000lm are shipping with HDBaseT built in. If your projectors have this as an option, you really only need to buy an HDBaseT transmitter and some CAT6A cable.

If for some reason you wanted to go with video over IP instead of HDBaseT, don't go with anything less than Crestron NVX or AMX SVSI (though with SVSI you need to specifically select a low latency part # that costs more). There are a lot of products on the market that advertise they can drive you video through a network switch but compromise on video quality and have long latency times. If you try to use those for IMAG you would get nauseous because of how out of sync it would be with the audio. If you go this route, you really should expect to be spending $1200-1300 per encoder/decoder for a production-quality solution. That said -- for that price tag you are future-proofed for the next 7-8 years because these units support 4K60 and the costs coming down on projectors have just started to make 4K laser projectors more accessible. If your project is as cut and dry as it sounds though I would stick with an HDBaseT solution rather than go this route.


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## Ancient Engineer (Jan 29, 2019)

<sigh> I will take my bashing with two comments:

Comment one: Mnicolai - your comments lack good numerical references other than "quality", and "lower/mid-grade" when referring to componentry and their expected usability. Got any science to back up your claims of usability? How about the bandwidth differences between CAT5e and 6A from cabling manufacturers? Wait that is really a rhetorical question, it really doesn't matter.PLEASE PLEASE PLEASE don't humor me by answering any of that. I am a bitter old engineer who is out to mislead and cause unfounded doubt with technology that is beyond hot coal and bronze weapons.

Comment two: Chris15 - I will not engage in debate over the legality of using HDCP protected source material in a venue with "outside" attendees. I will not engage in the debate over rights using iTunes or Spotify in venues other than your personal headphones.

Now, get off my lawn.


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## Dionysus (Feb 18, 2019)

Im a HUGE fan of HDbaseT, I'd NEVER use an HDMI over 50' long (just can't be relied on) as mentioned above. With HDbaseT you MUST use Cat6A cables to guarantee video quality, reliability and distance. Note Cat6A not Cat6, not Cat5e. Yes the most expensive bloody network cable out there. But you can find some for more reasonable prices.

There are a number of manufacturers using the HDbaseT standard, which makes it easy. Personally, I have a Kramer boxes, but there are a number of others out there. If you go to the HDbaseT website it lists all manufacturers. Lots of options out there.

One of my favorite things about HDbaseT is that you get full awesome video quality, and can also transceive things like wired remote control, USB, and others things all on the same cable. Use it for my wired remote for my projector all the time so I can control the projector from the booth.


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## Jay Ashworth (Feb 18, 2019)

Ancient Engineer said:


> Looking at the HD-SDI approach we get the following:
> Using HD-SDI meeting SMPTE 292 (ref. c) and a moderate quality cable like Belden 1695A (ref. d) gets us assured working distances of 100M (20dB loss at ½ clock frequency of SMPTE 292 see ref. h),



1695A?

I'm on the horns of this issue this week myself (Epson L1405 projector), and I was speccing 1694A to go about 150 ft at 1080p60. Is that beyond the pale for 1694?


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## Ancient Engineer (Feb 20, 2019)

Well... you can get 6Gb/s out to 225' on 1694A according to:

https://info.belden.com/hubfs/resou...tal-video-distance-chart-product-bulletin.pdf

So, you should be in at 150'.


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