We are doing the same thing and have run a 2" conduit for the cables and will leave a pull string in to swap out as technology changes. Make sure you have adequate lumber behind to support the arm you will use to hang the TV. I bought my arm first, used two 2x6's and will mount the electrical box between. You should get the recessed box for electrical and electronic connections. My alcove needs to be 7" deep to hide the arm and back of TV, even though the TV is about 1.75 inches deep.

You will need an infra-red gizmo to wirelessly use your remote unless you have your cable box up there on top of the mantle. I just had my cable installed and even though it is all wireless the TV needs to be cabled to the cable box or use the little attachment. Is what the cable guy told me.

I just bought an ultra hi def TV ( samsung and fabulous picture BTW) and had to special order the 50 foot special ultra HDMI cable to feed through the conduit. we are waiting on that.

Watch out for heat accumulation from your FP vent pipe and insulate accordingly. We used roxal and the silver bubble wrap.

Good luck with your project

Awesome! I don't understand a lot of what you've posted, but my husband will. Thank you muchly!

In our new build home we have our TV over the mantel. Many here will discourage you from doing this, and I would have chosen differently, but we had no choice in its placement. Anyway, the electrician ran a "smurf" tube (it's blue...other than that, not sure why they called it that) from the back of where our TV would be placed to where our cable box is located in DHs office. The HDMI cable was then run through the tube to the box. Remote runs fine with no need for an infrared repeater.

We have 3 TVs over fireplaces. They are all fine/comfortable to watch, I don't get the fuss that some people make about not liking the height.

We have conduit run to connections in the basement for equipment. We had those IR repeaters for Apple TVs (which were kept in the basement and hooked to the TVs through IR repeaters run through the conduit) but they basically stopped working effectively after 2-3 years (and we paid a lot to have all this set up correctly).

I switched to SmartTVs in two of the rooms and in the third (the one right above the area in the basement where the equipment is kept) I got a Boxee. That way, I was able to get Netflix and all the apps without needing to use the IR repeaters because all of my apps are right there in the TV. I would highly recommend a SmartTV for simplicities sake so you don't need any extra equipment except cable/satellite (if you have either)

We have satellite TV (I don't want it, others in my house do) and the boxes for that are in the basement as well, but the remotes work w/o IR repeaters.

I think IR-technology may be fading...

You all are fantastic! So helpful and so appreciated!

FYI, in the shot you posted (it was my project) the cable box was attached to the back of the tv using adhesive Velcro! It was a suggestion from the audio/video company that sold my client the tv and the gadgets needed. They then added a wire with infrared eye from the cable box to the top edge of the tv, so she can use the remote to communicate with the cable box (cable box on the back of the tv was the best part, as the tv is in an arm, and we had enough room to attach the cable box without having the tv stick out past the edges of the surround.

jewelisfabulous, that's going to look nice. Just for future reference, it's called an overmantel. They were quite popular and often ornate back in the Victorian days.
beaglesdoitbetter, the problem with a TV over a fireplace is the height. It's so high one has to look up when viewing it unless they are far enough away from the TV. My hubby wanted our TV directly over our fireplace, but it was too high and two close from where our double recliners are placed for me to watch in comfortably. Instead we placed it as high, but over where the built ins will one day be at the far side of the fireplace. This allows me to comfortable view the TV by just laying my head against the back of my side of the recliner or while reclining. The mounting bracket we used also allows it to come out and be swiveled toward us as I can't comfortable turn my neck for more than a few moments. So yes, there are legitimate reasons some do not want to place a TV over a fireplace other than aesthetics.