Space bar can sound atrocious if you have tray-mount case with center and bottom poles removed and either:
- don’t use case foam or
- uses a thin foam that doesn’t touch the the PCB.
For me, I don’t use a case foam when I want to emphasize switch sound or if the case is acrylic and PCB has underlight RGB.
When the space bar sounds like shit with such a build, I place a strip of case foam or Sorbothane under the space bar only, thick enough to touch the PCB. When a strip of foam is not available, use a folded sheet of tissue.