I’m not necessarily a veteran but here’s my 2 cents.

I would do some sound proofing, maybe buy a large floor rug, and definitely abide by any “quiet hours” rules from your apartment.

You already removed your subwoofer, so doing the other above mentioned things you will have done your due diligence IMO. If the neighbor still complains then I believe that would no longer be your problem :p

Edit: Also that is a bad ass looking system OP!