slrstcs wrote:If I hook each speaker up to an amp individually, maybe Denon hi-fi amp, and quietly play music, would any voice coil damage or rub be apparent?
Maybe - I've never used that method.
I typically hear voicecoil rub when an open low E string decays. The attack may sound fine but, if it gets fuzzy as the note dies, that's a rubbing voice coil.
Another method - provided one uses extreme care - is to gently and evenly (e.g. hands at noon and 6:00 or 9:00 and 3:00) push in on the cone and release. The cone should move in and out silently. Any scratching is either gunk build-up in the gap or a scraping voice coil.