Hi I am in the process of building my outdoor theater so far I have a benq w1070, carls 6.75x12 flexiwhite screen and recently purchased 4 dayton audio io655b outdoor speakers and am needing a little help with the sound I do have a old magnavox av reciever I bought at a 1.00 auction to use last year but not really sure how to run the four of these speakers off of it I tried to run just left and right plus center it sounds good but not loud enough that way and have a unused speaker so any recommendations maybe a 2 channel stereo reciever any help, tips would be appreciated thanks