For a few VR games that are more of a viewing than interacting experience (like Statik, which is an EXCELLENT puzzle game with a free demo, or Thumper, which is an EXCELLENT rhythm game with a free demo), I prefer to just sit on my couch. For games like Batman or Job Simulator, that require more arm movement, I will sometimes turn my camera to point to the side of the room and use a folding chair to sit. For games that really require standing up (the only one I can think of is Farpoint), I just stand in place in front of my couch. Honestly, the only things you need to worry about are the camera height/angle relative to where you and your VR headset/controllers will be and how much movement space you have (not so much for walking, since the PSVR only has a roughly 4 or 5 foot square "box" of area that it can recognize, but more so for not hitting stuff). The Camera doesn't need to be centered to your TV or anything, it just needs to be centered to where you (with the VR headset) will be standing. I think some games recommend waist-level or head-level camera placement, but in all honesty it doesn't matter so long as it can see the blue lights on the headset. I would recommend maybe not putting the camera on a speaker. The vibrations from the sound might give you some slight tracking issues. Regarding free movement in Doom VFR, I would recommend checking out Farpoint for it's free movement system. You can literally just go anywhere in the game world without using the "warp" mechanic a lot of other games have (though I mean "go anywhere by pushing the joystick," not by physically walking, though you can do that to whatever extent the camera will track you).