I'm new to this forum - so hello to everybody. I need some input on some M&K speakers. Basically I'm considering setting up the following hardware: Yamaha RX-V1400RDS 3x M&K K17 4x M&K K4 1x M&K K10 sub So: Questions. (1) Any idea how that setup would fill a 4.25 by 7m room? (2) It seems that the K17s are 4ohm, but the K4s are 8ohm tripoles! Would this be ok for the amp? Would they sound as loud at the same level? Is it normal that speakers in the same range (which are reccomended as a set) are of a different impedance? Thanks guys (& gals!!).