Please help, I have a 5.1 surround system comprising of 43in Pioneer Plasma Onkyo Tx-Nr 1009 4x Mordaunt Mezzo 6 speakers = 2 front and 2 rear I have a Mordaunt Mezzo 5 centre speaker and mezzo 9 subwoofer I was wondering if I could change this 5.1 setup to a 7.1 surround by connecting the pioneer mounted speakers as 2 high front speakers as these speakers at the moment are not being used. The Pioneer speakers are PDP s37 side mounted. The speakers will be high enough as they are about 14in from the ceiling. BUT ARE THEY GOOD ENOUGH TO USE WITH THIS SETUP I WELCOME ALL ADVICE ON THIS MATTER. THANKS.