String, if it was me I think I would have just picked up the left speaker without disconnecting anything and moved it to where the right was and vice versa.
If the noise persist in the left you know its not the speaker, cable, amp or preamp, just the room.
I've had to do this to determine that a noticeable speaker volume difference was only the result of its placement in the room.
If the noise persist in the left you know its not the speaker, cable, amp or preamp, just the room.
I've had to do this to determine that a noticeable speaker volume difference was only the result of its placement in the room.