A mystery for you tech gurus out there

Hi all -

I am stumped, to say the least, at what could be going on with my home theatre system. My equipment hooked up is:

-Denon 1913-AVR receiver
-Dual CS7000 (Golden one) turntable (grounded to a casing screw on the receiver case)
-Marantz 5 disc CD changer
-Front speakers: Paradigm studio 60 v1
-Center and surrounds: Sony
-Klipsch subwoofer
-Panasonic plasma TV

So the issue revolves around the front Paradigm Studio 60s. Whichever one is plugged into the FRONT LEFT speaker output on the receiver emits an occasional, loud pop. Usually the pop comes in bursts, and sounds almost like a fireworks show would with a succession of airy-sounding, concussive pops.

I thought it was my receiver (I originally had a Denon 1911-AVR giving me the same issue) and recently got the 1913, and the issue persisted. I have tried using new speaker wire as well. The part that I cant figure out is when i go behind the receiver and switch the 2 front speakers around so that the speaker that was right is now left and vice versa, the popping now comes out of the right sided speaker which is now plugged into the FRONT LEFT output.

How can this be? Any thoughts or ideas?
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