Re: the post by Chuck and also attributed to The Absolute Sound.
I might have a suggestion for those folks in the position of building a new home:
When I renovated my home and upsized 49.9% (a limit to avoid immediate reassessment) we changed our service entrance drop and the old 4/0 Aluminum SE cable was surplused. I ran that from the new primary panel to a subpanel just below my new living room and as long as we lived there we never got the slightest dip when the whole-house AC or anything else kicked in - including anything from some extended low end synth to the Also Sprach Zarathustra intro.
I had a separate 20A circuit fed to behind each equipment rack from that subpanel in the basement area below so all runs were less than 15 feet. The only other runs off that panel were to my electronics workshop in the room below, and I could only be in one or the other so it never interfered.
As noted in the really long post, the two key issues are 1: to have the stiffest possible power source (large gauge wire) as close to the load as you can with the best possible connections and 2: have some sort of RFI/EMI suppression as close to the load as possible as well. Even ferrites on every cord at the point it plugs into the load will help a bit, although circuitry in the power conditioner appropriate to the specific load type is valuable as well. I would quote brands, etc. but that construction and circuitry was back in the mid 90's and is not pertinent in todays market.
As always, be sure to take time to listen and enjoy the music!