Power Conditioners to reduce Sibilance

Not sure if the power conditioner would tame down brightness in your system. When I installed Shunyata Hydra power line conditioner in my system I noticed overall reduction in noise floor, but I can't say that it reduced sibilance. You may want to audition different speaker cables and interconnects to begin with. B&Ws are pretty critical to upstream components, so if any of your components has a tendancy to be bright, it will be shown by the speakers. Also, you may want to try corner busters from Echo Busters or any other company that makes a similar product. Aside from that I don't know what else to suggest. However, be carefull with power conditioners as few brands and types actually can hurt the sound of your system. I know 2 brands that won't probably make it worst - Shunyata and Richard Gray. Steer clear of strip power bars.

Have you tried towing the speakers in so the tweeters cross in front of the sweet spot?

I would assume that your room acoustics have something to do with it. As you upgrade to more revealing equipment, sometimes the room will be more noticeable.

In my system, the power conditioner smoothed the sound out just a bit, but I don't think it will cure anything.

Rob

Thanks for all the replys. My room is actually an acoustic nightmare and am looking to add some canvas prints to tame things down a little. I have fiddled with toe-in but not to the point where they cross in front of the sweet spot so I shall also give that I try. I was actually looking to purchase a RGPG 400 but I will hold off to see if I can alleviate the problem by focusing on the room. Thanks again.