I am having a house built and next weekend the builder is giving me a few days for prewiring low voltage. Here are my questions before I buy the material:

1. What is the minimum size PVC conduit chase I should run from the TV location to where the A/V equipment is going to be located? Would 1-1/4" conduit be sufficient for running HDMI cable? Is there really a reason to run any additonal cables in the conduit beside HDMI if the A/V receiver is going to upconvert everything to the HDMI cable?

2. Should I use the low voltage gang boxes for the speaker wire at the speaker locations? Or should I use the open back/mud ring type? What is the best way to protect the wire from the drywallers?

3. Does anyone have pictures of an installing before drywall and after drywall?

Regarding question 1, I would say minimum would be 1.5" and I am running 2"! As far as other cables, I'm planning other cables because I never know or might want to run a computer signal (VGA). Either way, You'll kick yourself if you don't at least run component and maybe even another HDMI (in case you run out of HDMI inputs on your receiver).

I'd say use at least 2" if you can (and the gray electrical PVC, not white plumbing, since the curves are more gradual). I also ran my cables alongside, but outside, my conduit, leaving it completely open for the future. Since they were cheap, I also ran component and coax I think, just in case. But since you'll have the conduit, there's probably no need.

For boxes, I found the regular plastic gang boxes (same ones as used for electrical) were the cheapest and worked just fine for speaker wire, coax, etc. A couple of them (like where my conduit came to) I even cut off the back with my miter saw so they pretty much were like an open back/mud ring type.

Stuff the wires as far back inside the boxes as you can - that seems to be what electricians do with the electrical wires. If your HDMI cable is sticking out, I'd at least tape a plastic baggie over the end of it to protect against drywall mud and paint that the contractors may not be too careful with.

How do you run 2" plastic conduit thru load bearing 2x4 studs since code only allows you to drill holes that are 40% of the stud depth which is 1.4" diameter. Would you have to double up the studs? I need to go horizontally thru the studs above the fireplace.

Ditto on everything Bucky said. I did the same things - right down to chop-sawing off the backs of my HV blue boxes (it's hard to find 3 gang LV boxes!)

As far as 2" conduit through 2x4's, well you're out of luck unless you want to break code. I don't know about doubling up, but if you find a reputable source that says that is cod-friendly friendly then go for it. I didn't have to go horizontal, just up through doubled 2x6's. Otherwise, your option may be to run multiple 1" or, if they exist, 1.25" conduit. Don't forget that that dimension is the Inner Diameter, the O.D. is bigger and rapidly approaches your 1.4" limit on a 40% hole in a 2x4.

There is 1-1/4" PVC Conduit at the local Lowes, so I might run 2 to be safe. Thanks.

Is it possible to route your conduit through the ceiling/floor joist spaces, and then just straight down into the stud bay where you need it?

Mine was in the basement, and just going from utility room to the projector location in the ceiling, so I didn't have to worry about going through any studs.