Anything mechanical needs time to work itself in with other pieces, especially moving parts, and a voice coil definitely qualifies. You do not put a engine together without first breaking it in. The cones on a speaker along with the surround is not metal, but definitely move also. If this procedure were not that important then I don't believe a company like
http://www.northcreekmusic.com wouldn't bother breaking speakers in and then testing them to within .5% frequency response to match them in their speakers. Now to test this I suppose you would need a response curve of a brand new speaker, vs one that has been run through for 100 hours and see the difference. To quote them "For perfect pair matching, tweeters are broken in with 24 hours of pink noise, while woofers receive this along with 24 hours of a 25 Hz 1/3 octave warble tone. Perfect pairs are matched to within ± 0.5dB and provided with anechoic 2pi frequency response and free air impedance curves. Woofers are also provided with T/S parameters." If this wasn't necessary I doubt they would take the time it requires to do it.
