I'm thinking about purchasing a set of Athena Micro 6 surround speakers which is a 5.1 set-up. I already ran speaker wire for 6.1. I found where I can buy a single speaker online to fill the 6.1 channel. My question is will this work? On their website it's stated that the sub cross-over is factory set with no adjustment to perfectly match the surrounds. Has anyone else tried this? Thanx.