Theaudiotweak...The 3000Hz tweeter to which you refer has a voice coil that pushes one way on its dome and the other way on a speaker enclosure. You ask us to believe that it moves the 40 pound enclosure more than the half-ounce dome. Obviously you have never heard of Isaac Newton.
Perhaps you are thinking of the woofer moving the enclosure that the tweeter is mounted in. Although the woofer cone is heavier than the tweeter dome, the mass of the enclosure still dominates.
If you want to worry about HF being corrupted by LF vibration think about how HF (say 1500 Hz) is generated by a mid/woofer cone that is simultaneously vibrating with large amplitude at 150 Hz. I believe this is called "Dopler distortion".
The walls of some speaker enclosures do vibrate, but primarily as a result of internal pressure from the woofer. The vibration amplitude is much less than the cone excursion, but there is a lot more area of the enclosure, and significant spurious sound can result. Heavy enclosure walls, internal bracing, and, best of all, curved walls will stiffen the enclosure walls and solve this problem.
Perhaps you are thinking of the woofer moving the enclosure that the tweeter is mounted in. Although the woofer cone is heavier than the tweeter dome, the mass of the enclosure still dominates.
If you want to worry about HF being corrupted by LF vibration think about how HF (say 1500 Hz) is generated by a mid/woofer cone that is simultaneously vibrating with large amplitude at 150 Hz. I believe this is called "Dopler distortion".
The walls of some speaker enclosures do vibrate, but primarily as a result of internal pressure from the woofer. The vibration amplitude is much less than the cone excursion, but there is a lot more area of the enclosure, and significant spurious sound can result. Heavy enclosure walls, internal bracing, and, best of all, curved walls will stiffen the enclosure walls and solve this problem.