Distance of Rear Speakers

[kevbach]

I am in the process of putting together a 7.1 system in a room that is roughly 15 X 35 feet I am going to have a pool table and some other stuff in there, so the couch is going to be in the middle of the room. The side speakers are going to be directly to the left and right of the couch, but I am wondering if I can put the rear speakers on the wall opposite of the TV - about 20 feet from where my couch will be. Looking at some of the 7.1 diagrams, they might be too far away but I wasn’t sure. This will be the most convenient place to put the speakers, so Im hoping it will be ok.

Anyone have any input?

 

[MDS]

You have to work within the constraints of the room so if they would ideally be placed 20 feet back, then so be it.

The only potential issue I see is that some receivers (at least my Onkyo) have restrictions on how far away certain speakers can be when you specify their distance in the setup menus. Those distances are for the time alignment (delay) features to work properly so that the sound from each speaker reaches your ear at roughly the same time.

I don't have the manual in front of me but it is something like the back speakers can be set anywhere from 5 feet less to 10 feet further from the distance to the front speakers - so if the fronts are 10 feet away you would be able to set the back speakers at 20 feet but if the fronts are closer you wouldn't be able to specify the actual distance to the back speakers.

At worst, you would have to lie to the receiver slightly but since sound travels roughly 1 foot every millisecond, if you ended up telling the receiver the back speakers are 18 feet away when they are really 20 feet away, it won't exactly destroy the sound.