I am an engineer, and familiar with the breakin characteristics of elastomers used for shock mounts and for speaker surrounds. I think that speaker breakin changes are related to changes of the properties of the surrounds, principally softening. This will usually result in better LF response, both frequency extension, and sonic quality.
The "conditioning" process (a better word than "breakin") depends on how much the elastomer is flexed as well as how long you do it. If you set your speakers going with a reasonably loud LF warble test signal in the morning when you go to work there should be a noticable improvement when you come home. If you just play music it could take many hours as you suggest.
Disclamer!! (These seem to be popular lately). I don't believe in breakin...except for speakers and phono pickups.
The "conditioning" process (a better word than "breakin") depends on how much the elastomer is flexed as well as how long you do it. If you set your speakers going with a reasonably loud LF warble test signal in the morning when you go to work there should be a noticable improvement when you come home. If you just play music it could take many hours as you suggest.
Disclamer!! (These seem to be popular lately). I don't believe in breakin...except for speakers and phono pickups.