So I've always noticed the impeadence/graph phases on most (good) subwoofer companies manuals, but I've never understood necessarily how they worked. Of course I know what impeadence and phase meant, but not too sure how it works on this graph (the frequency on the X axis, resistance on Y). To my understanding, it has to do with backpressure in the intended enclosure, so at the certain frequency where the resistance peaks that is where the backpressure in the enclosure its meant for peaks? And as for phase I guess thats just saying that 1 line is at 0 degrees and the other is at 180? But thats my guess whether its right or wrong the factor of backpressure? I've been getting into more advanced mechanics of audio but I've never fully understood this graph. Thanks you guys! MayemX <--- Not mayhem this wasn't a spelling error