[retrodrive]

They sound pretty good (surprisingly) however most of them have horrible reliability. I have seen more burned perfects then any other subs out there.

 

[retrodrive]

Each day I would do a bench mark with my eyes closed, when the car was running, how responsive my subs were becoming.

By the 2 week break in, my subs were much louder and very responsive to the lower end of the spectrum.

It is true that brake-in makes subs sound better but I really doubt you would be able to hear any changes in sound by day-to-day auditionings. The only way to tell the difference is to listen to a new sub and then listen to a broken-in sub within 30 seconds (auditory memory span). Otherwise all the differences you hear is the matter of imaginary perception.