I am looking at an Elite motorized 16:9 100" screen. Is Elite a reliable company? I'm worried because the screen is only going to cost about $175 which is very inexpensive. Also, does it have the ability to have speakers behind it? I want to make it feel like a theater when the screen is down but I did not know if sound is able to travel through it. Also, does the screen allow for good 3D viewing?