i have an Ampeg SVT-3 Pro and i run it through a single Bag End S15-D. i'm thinking of getting a second cab but i'm worried cause i know this head has a rep for being a bit underpowered. i get plenty o' power through the 1x15. this boils down to an impedance question for me. yes, i know there are many threads on this subject but, hey, i'm still confused... 1. the head puts out either 4 or 8 ohms. 2. the cabinet is rated at 8 ohms by itself or 4 ohms if its paired with another 8 ohm cabinet (i think, please correct me if i'm wrong here) so... if i get a second 8 ohm cab, they will both have an impedance of 4 ohms and my set up will be louder because although there are two cabinets to power - they are less "impeded" ?? is this a logical assumption?? this stuff boggles me.