So basically.... The when the bind post straps are on, the total impedance averages 8 ohms. When the straps are removed each section would about 16 ohms. I assume that the drivers and there crossovers are connected in parallel to the inputs, not in series, as then the crossovers would not function properly. Just so everyone understands where I am coming from....I have a seven channel surround amp that I only use three channels of (L R C). I can control the crossover frequencies to each channel. The amp(s) say 8-6 ohm load. In the amplifier manual it does tell me how to bi-amp a speaker. The amp is a Marantz NR-1601.