Does it matter at all if I put the port at the top of my sub, as oppsoed to the bottom encap? I don't think it should, but I'm just making sure. Also, is there anyway to use a speaker grill to cover the port opening on top? Hopefully someone has a picture of how this was done. I dont think I'll be able to fit a 24" tube in my room, so i'll have to go to an 18" probably and port the top.