HDMI length limit?

[Scuba Diver]

Okay, I am sorry if this has been asked but what is the maximum lenght a HDMI cable can be without signal loss? I guess I should have read through the forum more. It appears that this has been asked a dozen times. Sorry everyone.

[Mike P.]

50 feet has been used by some people with no issues reported.

[Scuba Diver]

Thanks.

[MatrixDweller]

It all depends on the thickness and quality of the cable and what you want to pass over it. 1080i/720p signals can be run over a modest cable where as 1080p signals require a more robust one to go over a long distance. A standard 28 or 26AWG HDMI cable would probably be fine for 1080i up to 25 feet, but it won't pass 1080p very well. A 22AWG cable would definitely work for 50ft at 1080p without a signal booster.

I have a 25ft 24AWG cable I bought from monoprice.com and it works well. I haven't tried 1080p as I don't have a source to do so, but 1080i comes through perfectly.

[Prof.]

MatrixDweller wrote:

I have a 25ft 24AWG cable I bought from monoprice.com and it works well. I haven't tried 1080p as I don't have a source to do so, but 1080i comes through perfectly.

That's good to hear...I've just ordered the exact same length of cable from Monoprice..

[John Simpson]

The OP raises a good question: there seem to be a few companies out there promoting electronic "booster" boxes to improve HDMI transmission. It's strikes me as odd that a new digital transmission method could have more problems than a regular component cable. Was this something that the earlier HDMI formats had, or is it still something to watch out for?

In an event, it always pays to run conduit through your walls, just in case your cable doesn't perform well and you need to replace it later.

[Scuba Diver]

You know seeing the boster is what originally sparked this question in my mind.

Conduit is a great tip. However, in my experiance if you are not building from scratch it is just as easy to snake a new cable. Either way running new wiring is expensive. Purchasing the right cable the first time is much more cost effective.

[MatrixDweller]

Computer networks suffer from the same problem. HDMI is a digital signal too so it's not a far stretch to see what's going on. CAT5e (100MHz) and CAT6(250MHz) become unreliable after 90-100 meters. Repeaters are required at or before that distance to ensure reliability.

CAT5e uses 24AWG copper primarily and CAT6 uses 22 or 24AWG copper. HDMI 1.0 is up to 165MHz or 4.95Gbits (1080p60) and HDMI 1.3 is up to 340MHz or 10.9Gbits (1080p60@48bits). Try to pass that signal over 28AWG copper and it's not going to make it 25 feet. Bump up the AWG of the wire and you'll reduce the attenuation so 24AWG will give the signal a longer run and 22AWG even longer. Attenuation increases when the transmission frequency increases though too. 1080i/30 or 1080p24 signals are not as much of a problem since they have a lot less bandwidth than 1080p60.

So HDMI 1.3 cables will either need to be fire hose sized, or have some other way of mitigating the attenuation to stretch the distance. That's where repeaters or signal regenerators come in.

[dwayne mifflin]

mux labs has a balunes,i think thats how its spelt ,that claims it will transmit hdmi through sheilded cat 5e up to 1000 feet. ive never seen it in action though.