Break in period for Cobalt woofer

Depends if you want to learn the dance steps )

Generally speaking, woofers--and pro sound woofers very much so are stiff when brand new. Some folks that build speakers and design their own crossovers will "break in" the woofers for awhile so they get a stable impedance reading when testing them to build their own passive crossovers. They usually just hang the speaker up with a piece of wire and run a low frequency tone through them to get movement and let 'em rip for a day or two.

If you have already built the speaker, I'd run some low frequency dance type music through them to get the woofers moving--no need to blast them so if you don't want it too loud, boost the sub bass EQ and roll off the mids/highs. I did that with my 88 Special build, cranked the 63Hz EQ band +6dB and rolled off the mids highs and brought up the volume with EDM type stuff at around 15 watt peaks. The woofers are running full range so will tend to get some stroke going with bass frequencies far below it's tuning frequncy. Long stroke with lower power helps keep those new voice coils cool, stretches the spyder/surround and won't blow your head off with SPL. You can also put the speakers with the drivers pointing at each other and wire one of them out of phase. That helps cancel out the bass to limit annoying other beings in your abode that don't enjoy the process as much as you.

For PA speakers back in the day, I would just run music at a few watts for 5 minutes then bump it to 1/10th the RMS rating of the speaker for an hour then start pumping in more power. Don't overthink it--you might notice the bass response is a bit higher in SPL down around tuning--or not. Once you get those cones moving, the sound will change starting in a matter of seconds to minutes--the concept of weeks to months of use is mythology and not based in reality. Community will do a break in/QC test on their speakers by running them for 24 hours connected to a computer. That is not done for sound quality, just a burn in test to find any weak drivers in their production line.

I've heard stuff along the lines of 300 hours of burn in with the first 10 hours being at a watt or two and so on. Speakers are electro-mechanical air pumps so breaking in the spyder stiffness and suspension stiffness is pretty quick. The biggest changes happen in the first minute and after an hour--it becomes almost unmeasureable. Danley Sound Labs did test it and things do break in but much, much faster than you think. For most people, just throw some music at them and screw around with positioning and location in the room. If you are afraid of damaging them, break them in with a romantic comedy before throwing in Sci-Fi or action movies. Enjoy your new speakers!