adding this for cross reference:
Also one thing to consider:
Sound travels a lot slower than light, so lets say you sit 5m away from your speakers.
thats 14ms of delay right thereā¦ 
(340m/s speed of sound at room
temp approximately).
measure the actual delay using a highspeed camera its fun. I dont know how
many people watch tvā¦ things are something off by a LOT.