:withhomo and yes you should break it in. you should play it at about moderate level for at the very least 30 hours (not continuous), about 2 weeks worth. This is what I was taught by several company representitives. breaking in allows the spider, which is a part of the speaker that helps maintain linear movement of the voice coil, to maintain control over the entire cone movement.
:withhomo
I used to design speakers and they should always be broken in first. They have T/S parameters for each speaker but those aren't the T/S parameters when it's sent. Those are the T/S parameters once the surround, voice coil, and spider have been broken in.
From the factory, the spider and surround are very stiff. I'm not talking a little stiff....VERY stiff. If you blast them immediately, you stand a good chance of lifting one of the two (spider is most likely).
The glue that holds the VC wires in place is cured by heat. From the factory, it's not 100% cured. As you play the speaker, the wires heat up. This causes the glue to continue to cure and smells.
If you don't break in your speakers (especiallly subs b/c of the travel), you can easily break them (even if you're under the recommened power). If they don't break, the T/S parameters won't be what they're expected to be.