Swapping speakers and blowing a channel is a short in the wires which the op created.
No matter what else, that fact the op swapped the speakers and immediately had the failure is CLEAR it is a wiring issue the op caused.
I would bet 100% that a short in the wiring is the cause.
Check you amp rail fuse.
If it has them, you are saved, just replace the rail fuse in the amp on the blown channel. If the amp does not have them, then your amp is toast.
No matter what else, that fact the op swapped the speakers and immediately had the failure is CLEAR it is a wiring issue the op caused.
I would bet 100% that a short in the wiring is the cause.
Check you amp rail fuse.
If it has them, you are saved, just replace the rail fuse in the amp on the blown channel. If the amp does not have them, then your amp is toast.