IIRC, Ian uses the cabinet resonance, while most others try to stop it, this, IMO, is what gives Axiom's subs their superior musical qualities; so I wouldn't be tinkering to much with Axiom's subs.
Good point; you would not deaden a piano or guitar as the whole makes the sound. I forget who, but some speaker mfg claims to tune the cabinet to work like a large musical instrument.