The T/S parameters will change with use which is normal but I think that people are talking about the implied damage that will occur if the subs are not broken in. Not breaking in your subs will not damage them, if the music you are playing does not make the subs exceed their mechanical limits no damage will occur. The subs will loosen up with use but any use will do(as long as it doen't exceed the mechanical limits) "breaking them in" with the above methods only gets you there quicker in most cases.