Quote Originally Posted by Reffc View Post
That sort of misses the point. Any significant amplitude in the sensitive midrange frequency or lower upper frequency is bad, and adding resonant panels of a different frequency isn't really damping since it has no effect on anything other than it's own frequency (or equal multiples thereof).
Depends... what matters is the final resonant amplitude and frequencies. If all parts combine to create a resonance which is out of important ranges then that could be good.

A panel which resonates at a slightly higher frequency to the tuned air inside (for example) can greatly dampen those resonances as the energy of one will be absorbed by the other rather than resonating in sympathy.

I've no idea what the Bosendorfer speakers actually do or how they work though, just talking very generally here..