I moved my floorstander HEPA filter into my living/listening room (not for improved audio reasons) and heard popping noises coming from the speakers. I was playing CDs and as long as the device was in the listening area, I heard the popping sound. There was no weird sound when the filter was behind the speakers.
Questionable Tweak
Someone on Audiogon mentioned using an air purifier to improve the sound of their system. I dragged my wife's purifier into my listening area, cranked it up, and.......,no change at all. They said it removes dust particles,to improve the sound. Has anyone ever heard of this?Is there any science to back this up?