Re: Dirty AC and the theater
The goal here, someone correct me if I'm wrong, is to be able to crank the volume up on all your amps and speakers without any input and be able to put your ear right up to the speaker and hear absolute silence. If the sine wave is pure and the voltage is stable with no RF or harmonic distortion on the carrier wave, then that's what you should hear. Thus the reason it's so important in a high end studio to regenerate all the electricity with U.P.S. to ensure there are no electrical outages. I imagine the better studios even have some kind of generator back up present for that occasion. I think the output of even a really good generator would have to be cleaned up and it would be expensive to isolate the low frequency rumble the motor would put out. Even if all the electrical was cleaned before it entered the main circuit panel, there's still miles of wiring in the average home that acts as an antenna and can attract RF, so the closer to your expensive rack of gear you can get to clean the power, the better. If a person was building a room from scratch like I will be, I think there are steps that can be taken with redundant grounding and high-end wiring to further limit the noise. I just hope I can still make it all affordable.