Whats the most common way to wire inside a wall?

Are you talking Cat6 and speaker wire? Is this for a new house that you're building? If so, you don't need to put wire inside the conduit but it is a good idea to run an empty conduit for future proofing.

At the wall you have a few options. You can either use the terminated cables wall plates you linked to or you can terminate at a plate with keystone jacks. I did the latter and connected HDMI extenders to the wall plate with patch cables. No problem so far.

Also, you may want to consider a recessed box for the above fireplace install like this one from Amazon. It'll give you lots more room to work with behind the TV which is especially good if you want to go with a very low profile mount.

Ah ok that makes things a bit clearer. What I meant by the Cat6 is that its easier and cheaper to run category cable and then use extenders at either end to convert and carry the HDMI signal rather than run in-wall HDMI cable. Extenders using the HDBaseT standard use one cable which can also pass ethernet and infra-red control signals. There are plenty of other, cheaper solutions using 2 cables as well. If you do this, you just terminate the cable at the wall like a regular telephone jack only you'll want 3 or more to each TV location I would think.

Attached is what my setup looks like. The far left recessed plate has 3x cat5e keystone jacks + an R6G. The center one has speaker plugs and then the rest is power.

I use one of these from monoprice. The HDMI plugs into it at either end. At the tv, its connected to 2 patch cables and then to the wall. In the media closet, I terminated the Cat5e and plugged the lines directly into the extender.

The two benefits of using the recessed outlet combo (the Arlington TVBox) is that you meet code for electrical (you don't want to have issues with insurance folks or resale) and it gives you space to hide adapters/baluns like the HDMI extenders ljo000 mentions.

And yes, it's better to go with category cable instead of HDMI (only - running both would be fine), as the HDMI cable is much more likely to be obsolete before you move.

Jeff

If you're going to hire someone to run power (doing the install 'to code') then that person can also run cat6 x 3, hdmi, RG6, and any other cables you want.

You'll use the hdmi now.

You'll use cat6 x 2 for a future extender, when the current hdmi cable becomes obsolete.

The extra cat6 is for connecting your TV to your LAN, for online services and firmware updates.

Retrofitting conduit is usually very destructive. I'd skip it.

Doing some drywall repair is cheap. Drilling through studs blindly can be extremely expensive.

If you want to DIY, post some pictures, for additional input from the group.

Read the manuals for the mount and the TV box. Research more online. Figure out every detail before buying anything.

You would only have 1 hdmi cable to that TV.

Since you have to go sideways, please, please, please hire a pro.

Call and ask. Many, if not most, will give you a quote for free.

Is there an attic above this room? Accessible?

This is a really, really bad idea.

Conduit would be for new construction, or a complete gut to studs. Skip the conduit, and futureproof by adding the correct cables now.

If you have an attic above that room, you would go up into the attic with the cables (from the equipment location), and back down at the fireplace. No blind drilling across studs required.

I'm guessing the fireplace has extra space around it, allowing you to come up from below (if crawlspace below), passing the cables behind or to the side of the fireplace.

An easy way to do this would be to cut holes in your drywall, at each of the studs you want to cross, and drill holes in the studs. Cables pass through studs to the TVBox cutout, above the fireplace. Patching and painting drywall is cheap, and super easy if you hire someone to do it.

But the easiest way for you would be to use the attic. From the attic, you drill through the top plate of the wall, into the stud bay, at both the TV and equipment locations. Fiberglass rods help you pull the cables.

Wire the TVBox with line voltage Romex properly. Again, if you hire an electrician for the outlet, then he can do the additional cables also. The easiest way to add cables is to punch through the drywall - so don't be surprised if that's what he does. Running cables into attic or crawl may cost you extra.

I think most electricians would charge $100 to add that outlet. Plus the cost of drywall repairs, the TV Box, and extra for additional cables (cost of cables and installation). You won't be terminating the category cables until you need them. But, you may want to purchase a terminated category cable (or learn how to terminate) for your LAN connnection to the TV, if needed in the near future. Buy in-wall rated cables.

I'm guessing, ballpark, $250 to have the TV junction box installed.

Hey - for these recessed outlets do they really satisfy code? Are they tamper resistant? This is being required for the home I am building in FL. I wanted to use the recessed outlets, but my electrician is telling me they are not tamper resistant.

Electrician is looking for an excuse to avoid the job. Find another.

The outlets need to be tamper resistant. The TVBox is just a junction box, it doesn't come with outlets.

A difficult client is often the reason to avoid a job like this. Don't be that guy.

The recessed outlets definitely pass code in MA. They're in my new build house which passed inspection less than 1 month ago.