Ive got yet another question on impedance matching. Ive been looking at an amp to power 4 speakers all four are 8ohms 100 watts a piece. Now the problem is that the amp states 8 ohm for speakers A or speakers B, but to run speakers A+B simultaneously it is 16ohms. If I run a speaker selector with impedence matching will this solve my ohm problem or are these selectors simply for hooking up speakers with different ohms.