Jim , although I've made clear that my preference is for a vertical center speaker(if any),I haven't experienced the major difference you describe(haven't heard the VP150). In addition to the rather remote possibility that your particular VP150 is damaged, the suggestions offered by Alan and others may be helpful. One possibility that you mentioned can be disregarded; you aren't "pumping so much power" through it. Most of the time about 1 watt is being "pumped" regardless of the maximum capability on brief peaks which the amplifier has.
