Before some people start thinking that a "huge" flaw in the Purifi driver was discovered today:
- any mechanical object on earth has a self resonance frequency
- any mechanical assembly on earth has a self resonance frequency
- the amplitude of this resonance can be lowered (or increased) by modifications
- the frequency of this resonance can be changed by modification
-
the resonance can not be suppressed, just mitigated
As usual with engineering, a tradeoff needs to be done between the function, the reliability, the manufacturability, the cost, ...
From the experiment done by
@Nuyes it seems here that the self resonance from the assembly or from one sub-assembly of from one component is around 380-400 Hz. It seems to be very well mitigated since the noticeable effect is a 0.05% distortion.