If your expensive new speaker still sounds cheap, this might be the real problem

There's nothing more frustrating than purchasing a new soundbar, surround sound system, or speaker system only for the audio quality not to be what you'd expect. It's the pain point of buying hardware you can't really test out yourself unless you're at Best Buy and can push a test button for a demonstration at a product display. But sometimes, the poor audio quality might indicate another issue. If your new premium speakers aren't delivering the audio immersion you expected and you have worked through every possible solution, the problem might originate somewhere else beyond the speakers themselves.

Source : https://www.pocket-lint.com/room-acoustics-home-theater/