WeitzC4

If I were a betting man I would say it's the amplifier, doesn't sound like it's blown if your swapped the leads and no distortion is noticed in speakers. If it were the wire it would more than likely just be shorting out and cause the amp to go into protect mode, so I doubt it's the wire.

I would personally switch the speaker channels on the amplifier and see if the static follows the speaker or stays at the location of issue. Help narrow down the issue to diagnose further.