Extra speakers in listening room

In a  dedicated listening room,  what is the proper way to handle extra speakers ?  Should one worry about two or three extra set of speakers? Should they be stored in the corners ? Behind the speakers ,or on far wall?  Do they have an affect on sound waves ? All extra speakers are ported cone speakers.The room is 13' x 14' x 8' . The  reference speakers do put out  extended base ( Usher 6371) .I am moving and loss my storage space.I do have  climate controlled storage space several miles away. Thanks for any  thoughts.