With how far technology has come in the car audio world, is it still necessary to break in brand new speakers and subs properly before blasting them at their peaks?

 

Only if you use the expensive cables.

 

Yes, you should always break them in properly. Dont peak them out when you first install them. Play your music lightly for a couple of days until the surrounds, spiders and everything else part of the speakers and subs are worn in. They will last you much longer.