My system consists of a set of dahlquist speakers all around and a svs pci 25-31 the amp is a marantz sr6200 dvd player is a harman kardon dvd-25 I'm using quality cables for everything. But for some reason when i watch movies at high/refrence level it sound very harsh and i have to always put it down 15db. At this level the sound is very undynamic but is sounds much smmother. The speakers are all over 90 efficency so the amp should have no problem running them at refrence (94 mains, 93 center, 90 rears) I have everything calibrated right and selcted all small for the speaker settings. The only thing that i see as the problem is the power supply. I suspect this is the problem because I have noticed that whenever someone is vacuming snow pops up on the tv and one time i was using a high current stereo amp on the same plug and the lights dimmed and flickered occasionaly. What kind of conditioner would help? I was looking at the monster power hts series maybe the hts2500/2600/3500 would this type solve the problem or would something better? Or could it be the marantz?