I have a 15" L7....just play it half volume for about 30-45 minutes...You'll smell excess glue burning off and so forth...after that, the suspension will loosen up a bit and you can really let em loose.
You'll be fine. You dont HAVE to break them in, but I was just safe and did it due to them being square. Stress points like they have, better safe than sorry. Just play it at moderate volume til you feel safe crankin' it.