Unfortunately, the only real solution is to move, preferably to a detached house that's quite a ways from the houses around it. Even then, if you like your music loud, you may get complaints, so you need to discuss it with potential neighbors before making a final decision.
Also, you might check your purchase contract. Often they include provisions for hours when you must keep noise to a minimum. People who are trying to go to sleep are much more sensitive to outside noise than when they are up and doing things.
There are some things you can try which will reduce the coupling between your speakers and the building, but they won't be perfect, and since your neighbor is already sensitized, they're unlikely to help that situation.
Marantz SR7009/7.1.4/FH+TM/DefTech PM1000/LCR+TM amped