I am running a 2.1 stereo system using a Yahama RX-797 100 wpc receiver hooked to two M70 plus a 12 inch Velodyne sub. The system sounds good, with big soundstage and tight base, but can be harsh in the mid-range. I would like to upgrade the towers. Everything I like requires substantial upgrades in the amp. Are there better towers than the polk monitors that will produce volume plus quality sound from a 100 wpc receiver?