Power cord / HDMI cable interference?

[Watchman]

Hi experts,
Sorry if this question has been answered on this forum but I can't find it...

I am mounting a flat screen and can either a) add a surge protected outlet behind the TV or b) use one of those power bridge soutions that essentially extends the power through the wall and allow an extension cord to plug in at the bottom with the advantage you don't have to run electricity to behind the TV.

Option b) is easier obviously but I am concerned that the HDMI cable bundle will be within a few inches of the Romex in-wall cabling and might cause interference. Should I be concerned? Seems like a lot of folks are using this solution. And if the HDMI cables are well sheilded...

My HDMI cables are HDMI 1.3a Category 2 Certified CL2 Rated (In-Wall Installation) Cable (24AWG) w/ Net Jacket..

Thanks

 

[Rickster71]

Welcome to Audioholics.

One option would be to find where the wall stud is located with regards to the TV's mounting. See if you can run power up one side of the stud and your HDMI up the other.
Old work boxes are available with a divider to keep the high and low voltages separated, as per code.

 

[Electone]

My plasma is not mounted on a wall, it is mounted on a stand with a pedestal. All my cables, including the AC cord and HDMI cable run through the same shaft. I have no interference or picture quality issues whatsoever. All of my power cables are plugged into a surge protector/conditioner.

 

[Watchman]

Thanks for the reply. Running power in the adjoining stud bay would require me to ultimately make a hole in the stud (because I don't want the power coming out of that part of the wall) and that's more work than I'm prepared to do.

The high and low voltage would be separated at the work box area (since that system has two separate gangs one for the power and one for the HDMI. Are you saying that running power and low voltage HDMI in the same stud bay is not up to code?

 

[Rickster71]

In the same bay is ok; though they should be on opposite sides of the bay, and not run together.
The code isn't concerned about quality of signal; their concern is from a pure safety standpoint.
If low voltage is kept separate from high voltage, there is little chance of the HDMI cable becoming energized.

 

[Watchman]

Great. So it 2-3 inches "separate" enough? The power and HDMI cable bundle will run staight down from the 2 gang box behind the TV to another 2 gang box at the bottom of the stud bay. So 2-3 inches is about the separation I will have.

 

[Rickster71]

It will have to be; since there is only so much you can do, working within an enclosed wall.

 

[Watchman]

Power cord / HDMI interference

Well, I did my best but I was unable to separate the HDMI cables and romex significantly within the stud bay. And now, it appears, there is some interference - when a source (like my PS3) outputs a black signal I can see little green dots all over the screen. If I run the source through the side HDMI input (as opposed to the ones that go through the wall with the romex, then I get no little green dots.

At this point perhaps the easiest thing to do is to try and shield the HDMI cables more, I can fish them out, them wrap them in something to insulate them, any recommendations what I should use?

Thanks.