I should have labeled it Speakers?

My system..... Vandersteen 5A, all Ayre preamp, amp, CD player     I thought someone might have a suggestion for noise in my system....sounds like a resonance in the upper mid/highs from the left. Noise remains if CD or Vinyl.  I tapped around the room with a big spoon to hear if anything was vibrating...none.  Changed the left/right cables..remained in the left.  I use a separate headphone amp with earphones...don't hear the noise.  Took out the tweeter and mid of left speaker and sent them to Vandersteen...good.  I sent the amp back to Ayre (150 lbs) ....fine. I checked that the cones under the speakers are tight. Richard Vandersteen, and Dealer Audio Connection took lots of time with me ....couldn't suggest anything I hadn't tried.  Anytime I listen to the system I listen for the noise and when the frequencies are "right" I hear it...very annoying.