So I started out with a TV. Then I put the TV through the Hi-fi speakers. Then I buy a cheap processor and get a centre and rears. Then I got a better AV amp and had stereo rears and added a sub. Next step was a new centre. Most recently an AV amp upgrade that can give me 6.1 if I buy an extra speaker. Now I see talk of 7.1 (whatever that is). Should I be installing ceilling and floor speakers so that the new 9.1 full surround can work, with sound not just going AROUND the room but also up and down it?